On the bench today an IBM XT in an unknown state I will try to revive.
Thanks PCBWay for sponsoring this video: pcbway.com/g/M525r4
Part 1: This video
Part 2: • This IBM XT had only O...
RGB To HDMI: github.com/hoglet67/RGBtoHDMI...
PS/2 repair series:
Part 1: • IBM PS/2 Model 30 - Un...
Part 2: • IBM PS/2 Model 30 (808...
Part 3: • IBM PS/2 model 30 - Fl...
Macintosh SE repair series
Part 1: • Apple Macintosh SE Rep...
Part 2: • Apple Macintosh SE rep...
Part 3: • 100% Fixed Apple Macin...
Restoration: • Macintosh SE Restoration
Adrian's digital basement HardCard 20 videos:
• IBM PC/AT Model 5170: ...
• Plus+ Hardcard 20 Fail...
00:00 Cinematic intro
02:36 Disassembly and cleaning
07:05 Motherboard tantalum replacement
11:13 Power supply test and power up
13:28 Video card repair
16:13 EGA RGB To HDMI
18:08 Power up
19:13 Keyboard issue and troubleshooting
25:39 Floppy drive test
26:42 Keyboard troubleshooting and fix
34:21 Outro
We want more
Will do! :) Thanks for watching!
Another way is to chop the tantalum’s close to their body and solder the new capacitor to the remaining legs. This way you don’t stress the metallic holes and avoid causing damage do the board.
That's probably a good idea - I don't like it particularly but maybe better than damaging the PCB. Thanks!
Not very elegant ;)
No, I agree. But if the option is to potentially damage the board, it might be something to be considered. But my first choice would be to remove them.
Low melt solder? Adding that to the existing joints before trying to desoldering might help.
I've done that many times. It can work well. I leave the legs a tad long so there is enough room to solder and dab a squirt of silicone under to keep them from "flappin in the breeze" (eev dave voice)
For fat ground planes desoldering, i usually simply use a very hot iron, like 400 - 420 °C and desolder quickly. Typically, the component is out of the board before the ground plane has time to sink heat all around too much. Since the goal is to do it hot and quick, i also always add fresh solder to melt the old quick. Pretty much all the lifted solder pads i ever had were done trying to desolder using normal soldering temps ~300 - 350°C.
That's a very good advice, thanks. I was thinking that 400C would be too much and I would damage the pads. But I see your point. My desoldering gun doesn't go so high though - well, it says it goes to 480 but that in its dreams. :) I'll try something like that, I also have a new T245 station which should be able to dump heat much faster than my previous one. Thanks again!
Always love XT content! And repair content! Learning something new every time 😊
Thank you for watching!
Very nice signal decoding of the keyboard! I really enjoyed that! Great job as always!
Thank you, I'm glad my unnecessary Binary troubleshooting was entertaining! :D
The old IBM PC:s and XT:s are iconic. Recommended.
They are - I'm so attached to my PS/2, I need to finish it and move it to my living room! Thanks for watching!
These intermittent faults are the worst. Thank you for the video.
ahah YES! So funny and frustrating! Thanks for watching!
0:15 I’m only 15 seconds in and that is one of the best intros from a retro / pc / electronics / repair video ever. I’m going to keep watching now.
ahaha thanks! I wasn't sure my audience would like it! :D Enjoy the rest of the expl... video!
@@tony359 that has reminded me I still need to get to the museum and see you. Work has been crazy so my apologies.
No apologies needed!
With old solder, adding new solder and using flux helps to flow it, then use the braid to remove it and clean the hole
I did but unfortunately the ground plane was sucking away all the heat... I got some low melt solder to try for next time. Thanks for your feedback!
if worried about damaging the board, chop the cap off on the component side, leaving a stub of wire present and solder the new one onto those stubs, it may not look brilliant but this was an 'approved' method by many manufacturers in the early days of PCBs to save/reduce track damage
interesting! I am testing some low melt solder - doesn't seem to be able to do miracles but I am still practicing with it. Thanks for your feedback!
I've never seen an expansion card with an HDD. You truly never stop finding weird cool old devices.
Thank you! It's indeed a cool card! Let's hope I can make it work in part 2! Thanks for watching!
I had a 5150 with one of those. Unfortunately it died :( So we upgraded to a 35MB 5/14" half-height drive.
You could also get them where you had controller and a standard 3.5" drive on one assembly that plugged into an 8 bit slot. Obviously they were thicker than the hardcard in this video, but you could at least replace the drive seperately. They came in 8 bit IDE and MFM/RLL form.
Big fan of old IBM PC repairs, just love how open and clear the technical reference guide is, really makes understanding how the computer works much easier, like the keyboard interface. Looking forward to pt2
Oh yes, HP was another one I think. It's times where things could be repaired... Long gone. Thank you for watching, PT2 should be online soon!
Really enjoyed the troubleshooting journey! 😄
Really happy you liked it, thanks for watching!
Great video again. eager to see the next video about this machine. thanks
Glad you enjoyed it and thank you!
Great video. Can’t wait for part 2👍
Thank you, coming soon!
Thank You for this great video. I can't wait for more, especially about hard disks.
Thanks! Part 2 has plenty of HDDs :)
Great one thank you sir! Love the cinematic intro!
ahah thanks! I was unsure about that intro, glad you liked it!
Great video Tony! As always, fun and educational -- I find I often go back to one of your videos when stuck on a project because you move quickly to first principles and DON'T spend the video wiggling wires (tho sometimes that's the problem, of course lol). But when wire-wiggling DOESN'T work, your videos are a good resource for getting down to serious diagnosing.
ahaha more wiggling next time! :) Thank you, I am honoured to hear that someone is using my videos in such a great way!
Very good video/repair.. The explanation of the Keyboard clock/data was freshly easy done. Good job from the first to the last second. For part 2 i want to see a slowmo of the tantalum explosions ❤
Thank you for your kind words! I'll think about the slow mo, maybe it's a good idea!
There are those that say, "if it works, don't fix it" and those that say "while you're in there..." I'm more of a "while you're in there" guy when I know that I can save it for years to come. It's also practical to leave things alone when you know that you might cause more damage. I've clipped those tantalums out by the leads and added more low melt solder (as suggested in the other comments) to better remove the leftovers. Leaving the lead allows me to get the desoldering tip over the lead and uses the remnant to help melt the solder. Just need to clean the desoldering tool every (well nearly every) time. Thank you for all that you do. So important to save these for future generations to enjoy!
Thanks - I never thought of low melt solder as I understand the inevitable leftovers will weaken the following joint. But in this case I might give that a go, thanks! And thanks for your kind words!
Excellent video Tony keep it up
Thanks for your kind words!
Thanks for the regular uploads, again, here's one of my very rare comment to get other people to see you! Loving your videos, calm presentation and skills I definitely lack :)
That's so much appreciated, thank you!!
Love the deep dives :)
Glad you like it! Thanks for watching!
Great knowledge thanks for posting
Thank you for watching!
Great job!!
Thank you!
The intro was great, I liked it!
ahah thanks! I was unsure of that intro but glad that several people enjoyed it :)
24:26 🤯MIND BLOWN! You are the first to explain that in such clear language. And thank you so much for windows programmer calc link. My son (10yrs old) does lots of programming and loves messing around with a calculator. I am trying to show him binary and hex so thank you from ❤ for that insight.
Hey thank you! That section took some time to make (I'm not a graphic designer!) so it's amazing that someone is enjoying it! Also amazing that your son is playing with Binary, well done!
Thanks for again a very entertaining video 👌
You're welcome and thanks for watching!
Thank you Tony :)
Thank you!
Well done
Thank you!
Hi Tony, with those heavy ground plane boards you really need to pre heat the board with a PCB pre heat tray, I don't have one either and wish I did, but I don't do enough now I am retired to merit the cost. You can cheat by heating the underneath of the board with a smd hot air gun while using the soldering iron on the other side, it helps. Bob. UK
Hey Bob, thank you! I do have a pre-heater, I just didn't feel like baking this 40-YO board this time :) Thanks for your comment and for watching!
Cool video. Thanks!
Thank you for watching!
17:00 👍 great use of the raspberry pie
I love the RGB To HDMI, it's simply amazing!
Thanks, great video!!
Thank you for watching!
Great video Tony! Really cool to see how the KB actually works. I have done many tests with these motherboards. I had the best result removing the tantalums by first heating the area with a regular heat gun set to the lowest temp for about 30 seconds. After heating the area the desoldering gun does the job perfectly.
Thank you! I did use my hot air (which goes up to 200L/m so not dissimilar to a heat gun I guess) but it really didn't work. Maybe I should have insisted a bit more? Or maybe the heat gun has a much higher airflow allowing a more even temperature. I'll try a few tricks - I'll also keep yours up my sleeve! And thanks for watching! How is your scope doing? Did you find one you like in the end?
@@tony359 Unfortunately my research led me to the MSO5074. I'm saving up for it and hoping it will come down in price meanwhile lol. I used the heat gun method in this video: kzhead.info/sun/ecN6dsudfImbqn0/bejne.htmlsi=aT95zm_p1ct9qhmW
Thanks for the link! Well... my board was hot to touch too :) I'm not sure to be honest! But I like your de-soldering gun. I can hear the vacuum, mine barely does that and I keep cleaning it. Which model is that? Nice scope, I hope to see it soon on your channel!
@@tony359 I hope to see it soon on my bench too haha. I've been using a Pro'sKit SS-331 for about a year and a half. I'm very happy with it so far. My heat gun is the cheapest no-name heat gun you could find in your local hardware store. I've had it for at least a decade, maybe two and it still does the job :)
Thanks. I'll check out the reviews. It looks better built than mine. You have an actual ceramic filter in the reservoir? I have a piece of sponge... What concerns me a bit of that station is the very small tip? It feels it might struggle with larger joints but if you're happy with it... Thanks for mentioning! I have a heat gun too, maybe I could try that next time - or maybe give my hot air station a bit more time. Sometimes I forget that temperature doesn't change in 5 seconds. Thanks!
That was decent troubleshooting.
Thank you!
great video, keep it up
Thanks, will do!
Amazing video Tony. I will use it as guidance when I can reach my IBM-PC and AT again. I developed a method on tantalum and caps (work with caps) but cannot explain it here in this limited text interface !!! Glad to share.
Glad you enjoyed! Feel free to share using whatever mean that works for you, my email is on my profile under "about"!
@@tony359 Will do it during the weekend. Hope you like it !!
I watched it with pleasure !
Amazing, I'm glad you liked it! Thank you!
Cartridge -style soldering irons (those with the heating element embedded in the tip) can really help when dealing with ground planes. You can get greater thermal transfer at lower temperatures.
Yea, I’ve just gone one, it’s amazing!! Thank you!
If Klaus was yelling in the background I would have lost it.
Nice job, well done. Great 'cinematics' ☺ Just be clear. You do know that a device places data on the bus, then sends an IRQ in sync with clock ? Component removal: remove the solder, then heat and push the component further into the board. Alow the area the cool. Remove any extra solder, cut the protruding pins flush with board. Heat and remove as per usual. A Bamboo Toothpick can be a useful tool here.
Data on the bus: yes but yours is a much simpler and effective explanation I guess :D Thanks for that! I'll try your method, as others say maybe I should have used a larger tip. Thanks for watching and commenting!
Yeah, a bigger tip might be helpful, I'm a bit paranoid about lifting, burning, tracks. Cutting the component off leaving the legs in-situ is equally valid I think.
I'm paranoid too and I hate when that happens!
Perhaps adding flux and low melt solder makes removing the capacitors easier. I did not try this myself but learned this from Alex and his repair channel Northridgefix.
A very generous use of flux (not just a tiny layer, a solid blob) would definitely help along with careful use of heat gun. As others have commented, a preheating tray is also really helpful. You should also clean the area before you start.
Thanks! My concern with low melt solder is that I understand that the inevitable residues will weaken the following joint. What do you think about that? I guess I shall give that a go though, thanks for your comment and for watching!
@Qngali I appreciate the pre-heater is important for motherboards - I just didn't feel like baking this very old one! Thanks for watching!
@@tony359 my point about flux is the more important thing, use a thick layer of it. Flux also have a cleaning effect for when you solder a component back in, it makes the bond stronger. Use it for both desoldering AND soldering.
I agree it's very important. I shall add some more next time!
I'll use a hot air station on a low setting to soak an area with low heat which helps on boards like these. I always add fresh solder as well.
Thank you. Sometimes I struggle with that too as in this video or in the "LivingControl" repair one... Thanks for watching!
I find it hard to get the solder out of power plane vias in many modern boards, too. Even after preheating thoroughly. I changed my method to just heating up the solder pads with the iron while pulling the cap out the classic way. Once the cap is out, the desoldering gun has a lot less trouble with getting out the remaining solder in the hole.
Thanks. The problem is that sometimes I can't even do that with my soldering iron! I've got a better one hoping it would help for multi-layer boards, watch this space and thanks for watching!
@@tony359 heat and then solder all the "pins/legs" together with a thick copper wire, be generous with the lead. Finally, pull the component
I use a ball of solder which covers all the pins. It usually works but sometimes... I used the copper wire too to remove a large IC without using hot air! That's a cool trick!
I have a Weller DS600 desoldering station and sometimes it doesn't cut the mustard. I turn my regular iron up to 450c and heat the back side while watching the front. As soon as I see the solder melt, I blow as hard as I can on the via while lifting the iron at the same time. Check for solder snot on both sides.
That's an option but I am not a fan of using 450C on a PCB, particularly a very old one! The Weller should be good though. I've just got a cartridge station, that might help a bit. Thanks for commenting!
@@tony359 No problem. KEEP UP THE GREAT WORK!!!! That's just what I do. I have never had a problem and I've worked some of the greenest battery corrosion cases and this new lead free crap that doesn't flow at all. Aluminum can caps whose housing is soldered to a solid copper ground plane... Cut heat and BLOW!
Thanks for your kind words!
I've been testing and repairing a large amount of PC parts of this sort of age this year. I had tants fail on about 20% of the boards, normally the 12V ones, at first power up. I only replaced the failed ones and i didn't have any more fail on subsequent power ups. It seems to me if they are going to fail they do it first power up. I did try measuring the tants first for shorts but never found any, they don't seem to go short until the power is applied. I change them them by cutting the cap off , remove the legs with the big bit in the soldering iron and then suck out the solder with the desoldering gun. I use the hot air gun to preheat the board before desoldering if need be. I think you needed the bigger soldering iron bit you used on the video card for the motherboard, it's not so much the size of the bit but the fact it's bigger and has more heat reservoir, the smaller tip just looses heat into the motherboard faster than the element can heat it. You also had the hot air gun too hot, it's just to preheat the board and the soldering or desoldering iron will do the rest. Add more fresh solder to the joint if it doesn't suck out fully straight away, trying to suck solder out of a half filled via doesn't normally work. As somebody else said, sometimes it's better to have the Iron hotter but you have to be quick, if it doesn't flow within a few seconds wait until the pcb has cooled a bit and try again. I use > 400C quite often without damaging the boards. Did you have to do any setup of your RGB to HDMI to get the picture ?, I've never been able to get good picture on mine, i assumed i needed to tweak the various technical settings but it looks like you just plugged yours in, set to the default PC EGA and it worked. Maybe mine has a fault. The XT keyboard cables also often break internally between the strain relief and the plastic cube though yours does look in good condition there.
Thank you for the comprehensive message, I appreciate that! Yes, I'm always lazy when it comes to swap tips - you're absolutely right and I should have put the larger on, I completely understand why. I've got a new station with 245 cartridges and swapping a tip is now a matter of seconds so it might help! Also the 245 can dump heat much faster then mine. I'll try as you and others say: hotter for less time. Also with the hot air, I cannot remember which temp I used. RGB To HDMI: I only skipped the section where I had to plug it to a monitor as my capture device didn't like its output - I think there is an HDMI setting in it. I set the correct CPLD, EGA preset and that was it. What you see on screen is what I got with no tinkering at all. I am so impressed, it just works and the quality is just stunning. Are you using the latest software? Thanks for watching!
@@tony359 Thank you, i think i will wipe the RGDtoHDMI SD card and try again. It was the latest software 2 or 3 months ago when i tried it. It could be a fault on the interface or on the PI, i think i have another PI i can try. Keep up the great videos, Jim
I remember back in the 80's when I got our first IBM PC and XT and having to run Autocad 1.5, We thought it was the best computer, I filled it up with extra memory card 1MB :-) and used the extra 384mb of memory as a RAM drive then added 2 Serial ports, Parallel port and finally install one the 20MB Hard card. The biggest issue was that I had to watch out for was the IRQ's and base address as trying to run all these cards was hard. I finally had to remove the parallel port to allow the Hard card to work... Many hours trying to make this work.. But I learned alot, there was no KZhead back in the days.. Compuserve if you were lucky...
ahahah yes the nightmare of conflicting IRQs and DMAs! Trying different ones until it worked! Amazing thanks for the memory!
Great find! What a pain of an issue. For us amateurs playing at home, could the IC that combines/regulates the two clock signals have been shorted in a way that 9mhz was being blasted out over an input pin (the keyboard clock one)? That's what I was guessing before you found the bad cable, but I don't know if that's even a feasible idea! Looking forward to part 2!
I’m not sure to be honest but it was 9 Hertz! Not megahertz🙂 I really don’t know where 9 Hertz could come from in a computer, modern or vintage that is! Thanks for watching!
I'd also be concerned about the caps in the Power Supply. Back in the day, it was common to use 6.3V Tants on the 5V lines and 15V tants on the 12V lines...It turned out that doing so was too close to the edge. When replacing tants with regular E-lytics, companies like Tektronix used a 3:1 cap ratio. Eg. use a 15uF E-lytic to replace a 5uF tant...
Good point about the PSU, I only looked for RIFA's :) Interesting about the ratio, I wasn't aware of that. I hope the ones I fitted will be ok then! Thanks for watching!
Desoldering alloy helps with large ground planes. It's very low temp solder made to dilute old solder so you can easily remove it. Just make sure to remove all of the alloy before reattaching because it because it'll weaken joints otherwise.
Thanks, I've purchased some!
@@tony359nice
for ground plane desoldering, you can try using low temp melt solder (like rose's metal), adding this to the joint you are desoldering helps a lot with ground planes, components just fall out themselves. However, you need to make sure to remove it all with a wick when done, as it would lower the melting temp for your fresh solder significantly and if the component is prone to heating, it risks desodering itself when in operation.
That's why I never used it, I'm concerned the new joint could be weaker. But it feels that - particularly on components not being mechanically stressed - it might be a good idea. Any pointers on which one to get? Thanks for your comment!
Sorry bought mine off line, but people say that chipquick has decent low temp solder. Although i share your concerns entirely, for me this is a tool of the last resort!
Then we are on the same page. It's a "nice to have" but not the first one to try. It's expensive BTW! :)
I think the cap leads were not straight when they were soldered originally ( =⎭=⎩=). You can: 1) push the cap down into the board hard while heating it, cut the ends of leads, pull it back up 2) have some tool to grab it well - possibly between the leeds, and pull with a LOT of force 3) remove the cap leaving as much of the leads as possible and then wiggle them around while heating from the other side. Find an angle that allows removal and pull pretty hard. 4) push the cap down while heating, cut off the cap, grab the leads from other side and pull while heating, Non of those are foolproof or universal but something you might want to try.
thanks for your input, appreciated!!
A bad technician repairs the problem. A good technician repairs the problem and prevents future problems. Change all tantalum and electrolytic capacitors on the board. It's the first thing you have to do before even plugging it in.
Then there is Tony, burning the board trying to remove a capacitor! :) Just joking. I usually replace all the electrolytic on something I really care about, otherwise I tend not to and only focus on issues. But I agree it's never a bad idea, it gives the unit some future reliability! Thanks for watching!
Low Melt Solder - forms an alloy with the original solder and reduces the melting point to where the huge heatsink which is the board doesn't prevent the removal of the through hole part. That and flux with desolder braid after will result in a clean hole. I like Amtech 559 flux but whatever is your preference. Then leaded solder to fit the new component.
I do have Amtech 559 (genuine one) but I moved to a cheaper one for less critical jobs. It's called Kingbo, it looks ok for smaller jobs. I'll source some low melt solder - it's pretty expensive! But I guess it's a "nice to have". Thank you!
@@tony359 A little goes a very long way.
Nice intro 👍
Ahaha thank you! I was unsure it would be get good comments :)
I had that same Conner Hardcard in a compaq luggable XT clone. I have also seen one in a PS/1? I think. It had a nifty little feature that when it accessed the disc it would blink a little ascii highlighted + in the top corner of the screen.
Ohhh that is indeed very cool! I wonder how that is done from a HW/SW perspective! Thanks for watching!
@@tony359 Been 30 something years I seem to think there was a utility but I can't recall if it was a TSR that loaded on startup or if it was just something that turned the feature on and off in the card. It worked on top of most DOS programs. You could be in word perfect and it would strobe occasionally in the corner. The card itself was like the XT IDE card of it's day you could plop it into just about anything it would fit in and it would work without much of a fight. If it works see if there are any utilities or entries in the autoexec/config.sys that might be related or a utility floating around on the drive probably in a root or dos directory. Been too long to remember but I marveled at it at the time they were able to fit a hard drive and controller into a single slot.
With all that steam power history in Swindon you would think that a 5160 would just work. They are basically steam powered. 😊 Great video as always. I like learning while you are learning. I am doing a rebuild of an Epson XT class machine right now.
It just needed some coal! I wasn't aware of Epson XT class machines, very cool!
@@tony359 Like Fujitsu and Siemens computers are not well known in North America, Epson didn't sell PCin most of Europe. Only in the US and Japan apparently. They had the Equity line. They are mostly 8088 and 286 machines. I am working on an Equity II which is a native NEC v30 machine. Basically the 8086 but a bit faster.
I remember the V30! Amazing!
I wonder if it would be better just soldering in the new caps, neatly on the top of the board on the old legs? I know it's not ideal but might be better than risking damage. Especially from a ‘hobbyist' pov who doesn’t have access to specialist equipment.😊
You are not wrong - if the alternative is to damage things, that could be a good plan. Thanks for commenting!
Nice. 51xx or a TRS80 are a couple computers I eventually want.
I hope I can tinker with a TRS80 at some point, they look so cool! Thanks for watching!
👍
The keyboard cable is probably broken in the strain relief of the connector. That is where mine were typically bad with same symptoms.
You're right! I wish it had shown when I checked with the multimeter. But then we would have missed all that beautiful binary section :)
@@tony359 This happens because keyboard cables tend to get snagged on stuff and then when someone is trying to move the keyboard out of the way they end up pulling pretty hard sideways, which breaks very thin flexible copper wires at the base of inflexible plastic filled connector. They make contact when you kinda push them together and break connection otherwise.
I've had good luck flowing a low temp solder in with the old solder and then remove with solder pump or wick
I shall try some thanks!
@tony359 I think fastchip is what I've used. It is designed to be added to the solder on quad flat packs and make them easier to remove. Lowers the melting temperature of the existing solder significantly. Usually by more than half
Thought the intro was awesome
The networkcard can be a ne1000 or Arcnet.
Thank you! Not sure about the Arcnet but the NE1000 seems to have a DB connector at the back which the one in this XT doesn't have? Thanks for your comment!
'Exploding Tantalums' would be a good name for a band.
What kind of genre do you think it would be? :)
@@tony359 Electronica, duh! 🎶
ahahahaha!
Always check simplest solution first!! :D
That would be too easy! :D That said, I did play with the connector a bit - and also checked continuity of the cable but clearly it was in a "ON" moment!
Leave the legs there and solder the new caps to the stumps 👍
That's an option indeed, I guess I can consider it next time, thank you!
i just had that keyboard connector problem a few days ago. the solution was to just replace the cable. it might have developed a break at some point, i don't know when. an easy way to replace the cable is to get a DIN extension cable off of ebay and snip off the female end.
i think adrian actually did a video on this a while back.
Good idea about getting an extension on ebay and snip the end! Thanks for watching!
FYI - A large number of 16bit VGA cards will run in 8bit mode, most never documented this. So you won't know till you try them in an 8bit slot.
I didn't think of trying as I found a web page with a list of compatible cards and the list was very short so I thought I could just save time! Well, the EGA had to be tested somehow and the RGB To HDMI is actually a great product so I don't regret purchasing it! Thanks for letting me know!
the easy way I think is to use a pre heater that will heat the goundplane just do not set it too hot then cut the caps and remove the legs with the soldering iron you would not beable to do it without pre heating the board
Of course and I do have it. I just didn't feel like pre-heating such an old board! But it's definitely the best solution! Thanks for watching!
Out of all the great work in this video, I'm just wondering what in the world is going on with your finger at 21:41?
Ahahah amazing! That’s the iPhone wide lens which is distorting everything the closer you are to the edges! I’m not an alien I promise! Well spotted!!
Uh huh. A likely story. ;)
I remember some old BTC enhaced keyboards with a switch stating AT and XT. The signal were diferent in those systems. The XT keyboard should work on AT, but I would rather check if the Keyboard is fully XT compliant.
There were so many keyboards made by IBM and sometimes distinguish them is not easy! Minuszerodegrees has quite a lot of information on the subject! Thanks for watching!
@@tony359 I remember the old XT keyboard. It was unpractical, but I loved PC-Write, the Shareware text editor. It adapted the weird layout to full effect. Later the enhaced keyboard made a more logical keys use.
I case you did not know this, you can use most 16-bit VGA cards in an 8-bit slot. So you do not need an 8-bit VGA card.
I didn't think of trying - there is a webpage saying that only a few selected VGA cards work with the 5160 so I didn't think of investing time on that! Thanks for letting me know though, I'll surely try next time!
Your XT was muuuuch cleaner than mine, which looks like it could have come straight from Pompeii 😂
ahah - I admit it was pretty crusty at the beginning but once cleaned it turned out pretty nice!
@@tony359 you could still see the PCB in yours even before it was cleaned. 🤣 If I could post a photo of how mine looked you'd be amazed at how dusty it was.
oh I can very much understand how those machines can get in 40 years! Unfortunately KZhead does not allow to post pictures on comments :(
You could try low melt solder, Indium Tin Alloy, it should be like magic. It works for me, but for newer stuff ...
Thanks. I got some after I shot this video. It works like magic for more modern stuff, I'm sure it'd help on those old ladies too! Thanks for watching!
were there any other companies that made boards this high quality? i have heard the ground planes on ibm boards of this era are huge.
They must be! I am told those computers underwent many days of testing involving ovens and fridges to confirm the equipment was up to the strict quality expectations of the time. After all it was IBM and those machines were EXPENSIVE! :)
Low Melt solder with plenty of flux will do the magic easily
Shall try thanks. I never considered low melt solder as I understand the inevitable residues will weaken the following joint? Thanks for watching!
@@tony359 the minuscule residue of the mix of low melt and normal solder after using wick or desoldering gun are way too small to affect the subsequent solder. Using low melt is gentle on the joints, pads, board itself and its a nice way to remove big chips, components that have plastic parts and/or big ground planes since you stress the board with less heat overall. The other technique you could use is preheat the whole board to around 100C-150C using a preheater or a reball station but it just depends on what your working on.
Thanks I shall try some. Any direction on where to get some?
Did you consider low melt solder? might be an option??
I never really considered it because I understand that residues might weaken the new joint but I've ordered some. I've also got a new T245 soldering station which seems much more capable when it comes to those multi-layer boards. Thanks for your comment!
use a low-temperature solder, such as rose alloy or wood's alloy
I got myself some bismuth solder, 138C. It should help for next time! Thanks for your comment!
8:25 I’ve heard learning electronics suggesting that we don’t need to replace them also Carlson’s lab. It’s an interesting subject: remove and risk heat stressing other components or don’t and risk it blowing. Let’s watch and find out….
Indeed - if you are still watching you should have got to the point where I make a decision about that!
5:03 I am very jealous. These hard cards were a shame re the company themselves. Too many companies did similar not so “good” clones and pushed them out of the market. Yet this ability to easily swap large storage media is the reason we have, SD cards, USBflash, compact flash and NvMe
Will it work? I see online lots of bad news about them. Maybe mine is luckier :) Thank you!
Typically you need to replace just one or two tantalums with electrolytics and just cut the rest off. As long as total capacitance is not lower, and mean ESR is not higher than what it was, you should be fine. Those older boards are much less finicky than modern ones.
Oh for sure. But wouldn't be the distance from where the device using the voltage is make any difference? Those are filtering caps, no? That's why you see them close to the memory bank, they filter very close to the RAM banks. If I removed them and install one closer to the PSU connector, some noise might be picked up on the way to the memory banks and cause issue - it's unlikely of course but it's "good practice" i guess? Thanks for commenting and watching!
@@tony359 It IS considered "good practice" but in practice it is not really doing all that much if the board is well designed, such as ground planes, sane routing, etc. Newer multi-layer boards with VRMs are more sensitive to ripple and positioning of capacitors. But on XT ones it is much more important that the capacitors in the PSU are good. You can try to do this: run a good random memory test (I'd say memory is the most fickle part on this board), snip one lead of each tantalum cap on one power rail where it can be soldered back, run that test again. If there are no errors, you can snip all those tantalums. If somehow I'm wrong, you can solder them back. Although desoldering them from that state may be harder depending on the method. If a couple of tantalums faile, it is quire reasonable to suspect others are somewhat likely to follow.
I see what you mean. I'll experiment a bit, thank you!
If you have an 8 bit VGA video card it is a good replacement for these units. [Provided you have an extra VGA monitor]
I don't! And only some VGAs work on the XT anyways and I only have a couple! Regardless, I'm looking for an MCGA one now as the 5160s were not sold with EGAs.
Comment to tell the algorithm that I like these videos
Thank you so much!
Any Reefers in that power supply?
Thankfully not :)
i've seen many videos of tants shorting and blowing up but not ....yet....had it myself,, plenty of RIFAs, and one occasion a load of multilayer ceramics self immolating! maybe mostly these 3 terminal ones, only have one thing with them, an as yet untested IBM MDA board
I had a tantalum exploding on me before - but that was me being silly as I mounted it backwards! :)
maybe just the ones on 12v? what voltage rating did they use?
@@tony359 oh, they definitely dont like it up 'em backwards 😉
Why bother desoldering the caps and destroy the board ? Simply cut them out and solder on new caps on the stubs. I know it does not look neat, but it can be done nicely and is definitely much easier !
That's an option indeed, I just don't like the look of it! But as you say, if the alternative is damaging a board... Thanks for your comment!
Never plug in an 80s era electronic device that has tantalum capacitors, without checking for power rail shorts fist. Ever.
RIFA, tantalum… they’re demanding things 🙂 thanks for your comment!
That's it for today... nah I'm joking, I'ma fix it... heh, got me there. I worked on an TFX power supply today, was just bad caps, but it still felt great when it just worked after replacing them.
ahah I'm getting carried away! Yes, that feeling when you fix something is so cool, isn't it? Thanks for watching!
You work in the cinema industry? Pretty cool. In what role?
All I can say is that you won't be seeing me on a movie poster :) It's a cool industry indeed, pretty unusual! Thanks for watching!
@@tony359 I was assuming it was behind the camera, but now it sounds to be in front of it? Nice.
But I said "you won't be seeing me" :) Camera lenses would crack if they try to shoot me! :)
@@tony359 Movie poster implied to me you weren't a famous actor, like the vast majority of them 🤷
why not using Ceramic Caps? or Tantalum?
I was recommended not to use tantalum as - unless bought from large suppliers - they might be very old and prone to failure. A good quality electrolytic should work fine in a filtering situation like this. Thanks for commenting!
@@tony359 Thanks a LOT for the tip. Is it same for Ceramic caps?
Good question, I do not know. But I never heard of ceramic exploding. If not mistaken tantalum's are electrolytic, ceramics are not. I think Ceramics are safe!
But why electrolytic replacements? Seems like new tantalums, or ceramics would be a better choice. (I just can't trust electrolytic caps not to leak)
In the UK it's not easy to buy small quantity of components from the largest resellers. They charge extra fees and shipping for small orders. So my options were 1. Use some tantalums I bought on Ebay - chances are they're 40 years old, who knows! 2. Wait until I need more components and place a large order: meanwhile I have a large doorstop (the XT) laying around my workshop! 3. Place the order anyways and likely be charged £20 for a handful of tantalum's (this is my hobby, I barely cover the cost with YT!) 4. Use the good quality electrolytic I had in stock :) I used Panasonic ones, if they leak it's going to be in 40 years time :)
Overdoing an analysis is always better than the other way around 😂
ahah thank you! Sometimes I feel silly when I spend days after something without realising the very simple problem before my eyes! Thanks for watching!
Use low melt solder
I’ll give that a go thanks!
@@tony359 you welcome 🤗
I would upvote is as many times as there are explosions. :) Sadly, I can only do it once. So here's a comment instead.
ahah let's find more explosive computers then! Thank you!
Heat gun is last resort, covering areas you aren't removing stuff important.
Yes, heating the board would help a lot, I just didn't feel like heating such an old lady... But it might be inevitable. Thanks for watching!
Yikes. I don't like those explosions - Don't know if I dare turn on any of my vintage PCs now!
ahahah - they're harmless but a bit scary indeed! I hope I didn't stop you from tinkering with vintage computers!
@@tony359 It's worth the risk! :D
always!
If you find PCs boring as well and are here just for the explosions goto 13:45
You missed one 🙂
@@tony359 the one at the beginning doesn't count
LOL!
15:00 " Testing video card explosion with a multi meter and it says it is made in USA by the card slot connectors and I never see anything made USA especially compterss 😂😅
ah yes! Well, those where other times where things were built like tanks! I was explained that those computers underwent strict testing processes - a day in a refrigerator and another one in an oven to make sure that reliability was 100%. Those were VERY expensive machines and there was no money spared! Thanks for watching!