Socket 7 motherboard repair - endless faults! 

So happy to see you here Adrian, I love your videos! Thank you so much for watching and for your kind words!

ahah indeed it's where everything started! I agree it's a cool video, lots of things happened there! Thanks for coming back! :)

Oh TRW is a valuable source of information - not sure how the Internet could exist without it! Thanks for watching and for subscribing, I look forward to contributing more to the database!

Thank you for your hard work !

Hi. I have a couple of obscure boards myself. If I want to contribute, should I post pictures in its original state or after I recap them?

I've run out of retro boards to repair! :D Thank you for watching and for your kind words!

@@tony359 buy more, simple as that

@@juliedunken1150 ahaha - I'm always trying of course! (spoiler: I just got another one for a future video! ;) )

Thanks for watching, Master! Your padawan is excited to have you here! :)

@@tony359 Oh, I please you... :D

wow two master here

I'll never use this board either - but we both know the feeling when they come back to life after many hours of work! :)

I am very happy you enjoyed the video and let me thank you a lot for your kind words! Indeed recording and editing those videos is a big task (getting better but still takes many days of work!) so comments like yours are very much welcome! Thanks for watching and for subscribing!

@@tony359 The effort shows, imho. 👍🏻

Thank you a lot!

Amazing! Thank you for your kind words and for watching!

Thank you a lot for your kind words, and thanks for subscribing!

Thank you Doc! 🖖

Thank you Hashem, it's very kind of you to say. I'm confident that one of these days I'll have some magic smoke coming out at the "three" :) Thanks for watching!

@@tony359 Thank you for all the knowledge you already shared. i will be binge watching them.

@@hashemmehyar9614 That is so kind of you, thank you! Please bear in mind that this channel is young so the older the videos, the... less polished they are (and some are very long!) :)

Eh eh I very much understand! Thanks for watching!

that's amazing! Well done! and thanks for watching!

Thank you!

This is incredibly useful, thanks! I'll definitely save this for future use!

Thank you for watching and for your kind words!

Thanks for watching!

Thanks for watching!

Thank you!

Thank you!

glad that the video had that effect, which I know very well! Thanks for watching!

Thank you for watching!

Thank you!

Thank you!

Thank you!

Hey Thank you! I have to admit that this one was a challenging (=fun) one! :)

Thank you!

Thank you!

Thank you Jérémie for your kind words! Welcome!

Thank you!

That is very kind of you to say, thank you!

Thank you!

Thank you!

Thanks Mark!

Thank you Sir, your channel is amongst my favourites, looking forward to your next videos!!

@@tony359 Thank you : ) Next video is out tomorrow : )

You're welcome, thanks for watching!

Thank you Hector!

Thanks a lot 😊

Thank you!

amazing, thanks for watching!

Thank you! I'm glad you like my magic skills! :) I shall post something here if I ever sold something - I honestly don't need all those Socket 7 motherboards! :) Thanks for watching!

Thank you for the comprehensive analysis, it’s so cool to understand those things. Meanwhile I have found some replacement so watch this space for a follow up!

Wow! I was lucky that all the voltages on my board failed by lowering their values! Someone on Vogons suggested to use a CPU which uses the highest possible voltages when testing a board. I don't have one yet and as you noticed testing the voltages beforehand is not always a reliable test! :) Thanks for watching!

Thank you!

Interesting! Those were fast moving times when it come to computer tech! Thanks for watching!

Old video but always nice to watch! Thanks for watching, obrigado!

Yes, I've noticed that some of those older sockets tend to fail to hold the module in place. I had to bend some of those clips in the past to allow the modules to click in place. Thanks for watching!

Eheh yes, il always learning when it comes to electronics. But at least I realised my mistake! Thanks for watching!

Thanks for watching!

ahah you know what, I didn't realise I said that! Thanks for watching! :)

Thank you!

Thank you for watching and for the feedback! Do you mean that white line you see on the video? If that is what you mean, those are white marks printed on the board every 10 pins - so you don't lose count when looking for a specific number. I had a look under the microscope anyways and I do not see issues there. But thank you anyways, 4 eyes are always better than 2! :)

Thank you very much!

Thank you for watching and for your kind words!

Thank you!

I can be persistent/stubborn! :) Thanks for watching!

Ahah yes they look so cool!

Amazing! Yes I like how you can now get those once-very-expensive-upgrades for peanuts!

@@tony359 Yes, I wanted to keep this computer going as long as possible, so I even added a couple of fans. There is one chip on the mother board that has a heatsink, but it still gets darn hot, so I extracted a tiny fan from an old dead Pentium module, and used that to keep things cool. The other fan is positioned on the front of the desktop chassis, and thus it helps with the overall air flow going through. The amount of dust that its blades quickly accumulate, tells you it is doing it job very well. I also added a fan to my 2009 SAMSUNG TV, and that made a huge difference to its overall operating temperature. This TV died at one point earlier on, but once again, all I had to do was replace one measly electrolytic capacitor. I may be an old timer at 65 years old, but I still get a kick out of fixing things like those mentioned, plus my 2004 microwave oven, and my 15 year old coffee maker, my 1987 DENON DCD-900 CD player, my 1978 home made speakers that each have one 15" woofer, 2 mid-range drivers, and 4 tweeters, my 1976 Heathkit AA-1506 audio amplifier that at one point went up in smoke, my 2008 Sony headphones, and a few other odds and ends. Saves money, and givers me something to do. Anyhow, Thanks for making a great video.

Hey thank you! Regarding the name, yes! :) I might reveal that one day! Thanks for watching!

Thank you!

From eBay UK, it was a UK seller. Pricey if I remember right. Did you check the legs? Thanks for watching!

Yep, pricy, fould some cheap on ali, but I wont try those. Ill look ebay, thanks. Yes, Ive checked all issues what you sorted out in your video. I got thinking, it has a 24/48MHz clock generator, myb its worth checking if the clock is correct, I hope it can be supplied from outside if its faulty, but I dont have an oscilloscope so can not check it.meh. The following pins sould be interesting by the datasheet: 7 CLKOUT O8 Output clock generated by the crystal oscillator 8 X2 O Crystal oscillator output 9 X1 I Crystal oscillator input 48 MODE IS Primary function is selected when this pin is low; secondary function is selected when it is high

@@bsvdoom interesting analysis. I didn't check on mine as it was scorching hot - so likely failed.

@@tony359 yep, mine is not hot so got my hope's up

ahaha yes!!!

PC-Chips were apparently very popular back in the days - some were good, some were not :) Thanks for watching!

Ahah thank you!

Thanks for your comment! Well I knew the PSU didn’t output 3.3V so it had to come from somewhere else. The CPU switching supply is variable so can’t be that one. That transistor looked like the only component suitable to be used as power supply so I checked continuity from the 3.3V supply of the ram (you can find pinouts online) and the transistor.

It does thanks! You’re not the first mentioning the P55C which I’m not familiar with. I shall do some research! Thanks for watching!

Thank you! New or old graphic cards?

@@tony359 only newer card. From gtx9xx to RTX30xx cards. I never worked on old cards.

@@gerrepair7862 on my stack of ‘broken things to repair’ I have an R9 270 which… works on some systems and not on others, powers up intermittently and funny things like that. I found a shorted cap which I replaced (the board still managed to power up and work with that though!) and that surprisingly didn’t improve things. Weird. I was thinking of reflowing it at some point but I couldn’t replicate the issue anymore last time I tested it 😂

@@gerrepair7862 on my stack of ‘broken things to repair’ I have an R9 270 which… works on some systems and not on others, powers up intermittently and funny things like that. I found a shorted cap which I replaced (the board still managed to power up and work with that though!) and that surprisingly didn’t improve things. Weird. I was thinking of reflowing it at some point but I couldn’t replicate the issue anymore last time I tested it 😂

@@tony359 I only repair nvidia ,for a got reason😅. The r9 270 has sometimes Problem with the GPU soldering. The question is ,it is the the connection from DIE to pcb DIE or is the connection between pcb DIE to card pcb bad. When you have problems with the card on some mainboard and one some not, check always the pex voltage and the pcie caps.

And I like Pentiums because they are superscalar and much faster than 486.

I hope Adrian won't mind if I took some... inspiration from his thumbnails! The opening is also borrowed from "The Slow Mo Guys" :) The board is currently cacheless unfortunately. I tried fiddling with some 0 Ohm resistors I found on the PCB but that didn't change anything. I'm trying to source some spares but I am not holding my breath! One of my viewers is trying to help, watch this space! I like my thermal camera (Seek compact Pro BTW, took me a while to find a "used" one at a reasonable price) but I have to admit it's not really so necessary for projects with larger components. Definitely more useful when components are half the size of a grain of rice! :) Thanks for watching and for your comment!

@@tony359 If the lower cache (the lower 128KB) chip is missing the higher might not be recognized. So maybe you can at least get 128 KB of cache if you desolder the one still present and resolder it in place of the first one. Had some similar problem with missing chip memory while fixing an Amiga 600 some years ago. Tried to find datasheets with pinout for the installed cache-chips, but found only a thread on vorgons where you were asking about that board shown in the video. ^^

@@devil5051000 Sounds like a great idea, I will try that for sure. I've felt that chip burning at times too so it might be faulty as well but I guess it won't hurt to try!

Re FLIR - eBay sometimes has cheap E4 floating around. As most here would know E4 = E8… next level would be cheap E40 which is sort of E60…

Good eyes, others have noted too. I had some footage about that but in the end decided not to add it to keep the video shorter! Thanks for watching!

Finished the video, what an amazing troubleshooting skill and also a superb set of tools! I think those similar chips from the Vogons thread will work, looking forward to the next episode!!

@@GabrielZ666 Thank you! You make me blush! I don't think I could find those chips either so I am trying to get some I have on a similar motherboard, UM61L3264F-6. Who knows 1. if they work 2. if they are genuine 3. if I ever receive them! :) Watch this space! :)

I tried yesterday night! The "selection resistor" (at least the one I think it is) seems to go to multiple pins on a chip so it's not easy to figure things out. I'd like to try sourcing new modules first, they are not so expensive. Failing that I'll think of something - a MB like that with no cache is no use to be honest... Thanks for suggesting!

For socket 7 this is the page I found more useful: www.pchardwarelinks.com/586pin.htm Please note the companion page where each pin is described, the link is on the same page. The pinout are when looking from the bottom of the board. For voltage you can use one of the many VCC2 or VCC3 on the board. A graphical visualisation of the voltage pins is pretty clear on this page: en.wikichip.org/wiki/File:CPGA-321_K6-2_pinmap.svg I hope this helps and thanks for watching!

Thank you! One of my viewer managed to send me a set from another TX board so watch this space as I'll try to fully restore that board!

That makes sense, thanks!

Good question. I feel the 3.3V power transistor damaged the cache modules with a spike - then it just dropped to 2.2V as to say "it wasn't me". But the RS232 buffer chip is 5V so... What if there was a 5V spike from the PSU, that damaged the RS232 chip, the 3.3V power transistor which in turn brought down the cache. Potentially RAM, CPU and anything plugged into that motherboard went. Then the motherboard was binned and got physically damaged. PSU are normally protecting the outputs but anything can happen (particularly on cheap ones...). What do you think? Thanks for wathing!

The video where everything started! :) That was a fun repair! Thanks for watching!

Oh sorry Tony, didn't know it was an old video. Hope things are still going well!

No need to be sorry! It was the first successful video of my channel and took me over 1000 subs :) I hope you enjoyed it!

Thank you. I think I tried that but ended up with a burnt copper wire? I’ll try again. Thanks for watching.

@@tony359 No worries mate. I would however suggest that you have look at Kynar wire (not the cheap knockoff stuff) for this kind of repair in future. If you must however use magnet wire be sure to remove the enamel before trying to solder it down, the extra unnecessary heat on the fine PCB traces can cause the traces to lift off the fibreglass subtrate causing further damage.

@@gnif You are totally right about heating traces, that is why I was disappointed about the outcome! I tried flame and soldering the wires before using them (require 400C apparently) but nothing gives me a clean result. Kynar wire is excellent but it's not available in small gauge. I'll keep researching and testing, thanks for your input!

@@tony359 Some flexible audio cables are actually multi stranded fine copper wires inside. Or maybe event the teased out screen wire would suit your purpose. Then you would not have enamel to remove.

@@Hereford1642 I know which ones you mean, they have very very fine strands. I can try again for sure. Thanks for mentioning!

Good point! I checked and they seem to be disconnected. I do not see any traces coming out of the 3.3V lines and I cannot measure continuity with anything. Another board I have have a jumper selection to be used for when ATX is being used - this one I am not sure as I do not have the manual. There is an ATX switch jumper and that's it.

@@tony359 Thank you. You know, I find fascinating the computers from transition periods. When I upgraded from 486 to Pentium, I also upgraded from AT to ATX without knowing it. Imagine my surprise not seeing "Now is safe to turn off your PC" message. Also is interesting to see what approach took the manufacturer to integrate old and new technology (SDRAM and FPM/EDO RAM in your case). That is why I was intrigued about 3v3 power rail. Also I find weird the thing that ATX dropped -5V that is needed for some ISA cards and is used on a ISA machine.

@@sebastian19745 it was an interesting period indeed! Things were changing so rapidly and computers were fully obsolete every 24 months more or less! :)

Yes it was recommended by Necroware. I got it from aliexpress but the one I got is not available anymore. I found another one which looks like the one I have (can’t guarantee it’s the same) and you can find it here: www.aliexpress.com/item/1005004052040884.html Thanks for watching!

@@tony359 Thanks for the reply, these won't work on the battery hand drills I have but they are still supper useful.

It’s an 8 ohm 100W one. Totally overkilled but it’s handy to use - I use those for testing amplifiers . I use ohms law to make sure that that’s going to be ok. 4V and 8ohm make 2W or 500mA.

@@tony359 Thank you. I wonder why you want to put a load on this transistor :) many times I do the same check but never put a load on transistor :)

@@elenium115 Sometimes a supply voltage can be off if there is no load. Check on my other video here ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-1kVps2oBmhs.html what happened when I tested the CPU VCC with no load! :) In this case the load was not the issue but I thought it could help.

@@tony359 Ok thank you for link.

Really! I wouldn't be surprised then! Wondering whether replacing those fake chips with real ones would enable the cache or whether the whole PCB was just not designed for cache!

I believe most of those mother boards didn't have any traces connecting the fake chips to anything except grounds.

That is very right, well spotted! Took me a few hours to realise, I put a subtitle at 5:09 to clarify! Thanks for watching!

Cool! I thought they would throw an error message, not preventing the whole board to post! Thanks for watching!

Hello - I got it ages ago. You’ll find many different models, they’re based on Arduino if not mistaken. I wouldn’t be able to say which one is the best one today (maybe one which is upgradable?) but it you Google for Arduino component tester you can find them cheap. It’s honestly super-useful but don’t do as I did and check a large capacitor still charged! 😂 thanks for watching!

@@tony359 Thank you for the information, I appreciate it 👍🏻

Well the X99 is a much modern board and it’s much more complex than a 1996 Socket 7 motherboard!

That makes sense and explain why on misbehaving systems sometimes working CPUs get scorching hot if they're not being initialised! Interesting, thanks!

Wow I didn’t know the motherboard was worth €50, my best guess was €20!!! 😂

who knows, maybe one day! This is "tinkering shop", anything can happen! Thanks for watching!

Wow thanks. :D 🙏

I have - also tried disabling/enabling it but unfortunately it made no difference. Thanks for watching!

Thank you!

It could be an idea. Some subforums might help. It also add a lot of fragmentation though. Food for thought. Thanks for watching!