No post codes. You can see the reset working but it just sits there after that doing very little. Clock and Frame lights are lit, not sure what frame means to be fair. Voltages all check OK too.
@@CRG I have a 286 board that does the same thing. Means the board is not starting. Try re-flashing the BIOS and then check for voltages and clock signals on the CPU and various ICs. Also, check to see if the voltage regulators are working. Maybe the CPU isn't getting power due to a faulty regulator.
No post code usually means the cpu isn’t able to execute bios code. Is the chipset getting hot? You might want to use ipa to identity if it’s too hot. If so, the chipset might be faulty. Power regulators might definitely be broken. Especially when there’s no heat sink attached. It’s a good sign! Good luck!
@@Inject0r The chipset IC to the left of the CPU socket gets screaming hot fairly quickly (after about 30 seconds) so I'm fairly sure that's where the problem lies. There is absolutely no activity on an address or data lines so for now I've conclude its dead. Time to move onto the next project box and hopefully with a bit more luck.
I made an offer on a Gigabyte GA-586HX which was "broken", it looked perfect the only issue was a lack of a BIOS chip and missing Dallas battery. Usually, prefect boards are dead but I wanted this board (even if it was dead) as I had one briefly back in 1996 (which was DOA) and exchanged it for a different board. So I flashed a BIOS image onto a 27c010 and inserted the battery expecting it not to boot at all, but it booted! Got lucky that time.
Well, a good approach is always start with checking voltages after fixing all obvious places with visible damage. In this case good idea would be to check what voltage you actually do get supplied to CPU, to chipset ICs, to PCI and to ISA slots. Refer to widely available docs on the Internet with info on what CPU socket, ICs and slots pins to check. Next point - obey KISS principle. You don't need memory or video card to check if MB is alive. Bare minimum is CPU (best idea is to use some common midrange one - like iPentium 120 or even Pentium 90 for this case) and PC speaker to be able to hear beeps. Even better would be to have ISA post card on hand to see if CPU is getting reset/running or not. For "voltages ok but no CPU activity" case first places to check are PowerOK and PowerOnReset circuits followed by checking BIOS IC contents. Yet another good idea for this MB would be to reflow all pins on IC that you were re-soldering some damages pins. It even might be reasonable to desolder this IC completely using a lot of flux and air gun just to check the condition of traces that are under the IC - you might have some more damage there as well.
Thanks for the detailed response. Some good tips in there and I will go and check voltages to be sure but certainly at the PCI / ISA slots along with various chips the voltages all look good. Didn't check the CPU but will do. I've since also tried a post card which shows the reset line working fine but then just sits idle. No post codes etc so my thinking is its something to do with the BIOS. I've checked the rom and it looks fine but also tried a BIOS image I found online for this board, same result. Keep the ideas coming though, always grateful for any help or advice. I'm not keen on removing that chip totally since my soldering skills may not be up to replacing it again, just want to rule out everything else first.
@@CRG Look up "How to troubleshoot your defective 386/486 motherboard with an oscilloscope" topic on the EEVBlog forum where I helped feipoa (true vogons legend that lad) with few dead boards, covers wide range of diagnostic steps. You do have a Hantek LA so diagnosing whats wrong shouldnt be difficult (just tedious). Start by looking at the Bios address/data lines if its being accessed at all.
@@CRG s7 boards were so simple there is almost nothing that cant be repaired :) If you need step by step help just post on eevblog in Electronics »Repair
@@rasz I've found evidence to suggest there are faults on the internal layers of the board. Discovered a missing 5v on one of the transistors bottom right but if I pull or push the component or even just flex the board it'll suddenly come back. Not much I can do to fix that and if there's that one internal problem there's most likely others.
Hi, nice channel! I have as many boards like yours awaiting repair, sadly with the same symptoms ... it's a little frustrating when it's not showing signs of life. Do not give up!
Superb channel buddy! Discovered today and subbed. Love the 486 Pcchips M912 build. Got the same board in a later revision. But only 128k cache with 16MB RAM and DX4-100. VLB SCSI and Primax Soundstorm GUS Clone and also an S3 VLB VGA with 2 MB. After watching your video i feel tempted to add a CT1600 to test if they knock each other out too on my board. Will keep you updated.
Thanks for the kind words and for subbing. I've since got the issue with the GUS sorted. Well mostly as the GUS is muting it's line in randomly but easy to sort with a simple command. If you do try the ct1600 alongside please let me know how you get on. I have a DX4 100 system to build at some point in the future, was tempted to drop that chip in the PC Chips build but I'm happen enough with the DX2 66 in there.
That would be a nice little Triton chipset board. Could be a stupid or already answered/tried question: are the CPU Vcore, I/O, BIOS ROM and DRAM voltage rails read nominal? Could be the person before you used it for a long time without the LDO regulator heatsinks. Does it beep the DRAM error code when there's no RAM installed?
@@chris-tal going to check that later to be sure but I'm fairly sure there is internal damage. Found a missing 5v with no signs of damage. If you push or pull the component or even just flex the board it'll come back. Doesn't bode well for fixing it.
@@chris-tal check the 14.(odd) MHz crystal on board which is fine. Not sure where the system clock is generated. Need to pull the datasheet for the chipset but going to check the bios address and data lines first.
My feeling is that the lack of boot isn't due to damage, but configuration issue. It's possible the CPU isn't supported. I would have expected at least a beep otherwise. Just discovered your channel thanks to this video. Awesome! Looking forward for more :)
That has crossed my mind too, that the processor might just not be compatible. I'll order up a Pentium 75 (or something similar) just to try. Always good to have more in the collection anyway. Plenty more to come on the channel so thanks for watching and please stick around.
Well you can actually use a 2.8V CPU. You have to configure it to "split voltage" operation :) Also, I think the way you've installed the EDO ram is wrong (it should be in pairs in two slots next to one another), but I doubt it'd prevent you_r board from POSTing.
If you look at the board the edo slots are labelled 0101 that's why I installed the ram as I did. Both are in slots labelled 0. But yes that's highly unlikely anything to do with why it doesn't boot. I've since tried the cyrix cpu at 2.8 volts with the split voltage but same result :(
@@CRG Yeah I noticed that but I think they meant slot N°0 of bank 0, slot N°1 of bank 0, etc. I've never seen a pentium board with a different slot layout than that (but this could be the exception nonetheless, who knows ?)
@@DxDeksor you might be correct but regardless its not the issue. Using a test card the board seems to get stuck after reset. Need to do a bit more reading on the boot process to understand what should come next.
@@DxDeksor no post codes. You can see the reset flash then it just hangs. Power rails are all good. Clock and frame leds are also lit but admittedly I'm not sure what frame is.
Ive been over the bottom of the board with my magnifying glass and don't see any. A complete relow will probably be one of the next things I try although it'll be difficult on the smd stuff.
I know I am very late to the party watching this one, but is it possible you need to briefly jumper a power "sw" header on the board to in effect turn it on? I have not looked up this board to check but that is sometimes a thing with older boards I have worked on.
I don't recall anything like that in the manual, well what I had of it. If I get the chance I'll take another look at it but I'm fairly sure the issue on this board is down to a fault in the chipset.
Have you tried to reprogram the BIOS EEPROM with your TL866? (providing you can download it somewhere) I myself had some luck reviving some dead SS7 boards just by doing that.
Yep I've since tried that. Found a bios online although in a bit dubious if it's correct or not but tried it anyway and no difference. The original bios is saved and to be honest the 2 files appear identical so the original was probably fine.
Even if the other capacitors look good, they might be "dry" and need to reform, by leaving the board on for a while. But i guess that can't be done safely without the missing heatsinks. Or replace the other capacitors too. When in doubt, change capacitors :D But changing throughhole capacitors on multi layer boards is no fun... Needs lots of flux..and then some more flux :p
@@8bitbubsy Well, with "dry" i mean, the electrolyte inside has to be respread and reactivated again; and with the board coming from the late 90's, it's actually more than 20 years old now. Also, if it just sat there without it being powered on, that wouldn't have benefited the capacitors. It doesn't mean it HAS to be the capacitors, but it's an option.
I recently had a socket 370 Mainboard that showed similar behaviour, with fans and peripherals like floppy and CD-drives initializing, but the screen stayed blank and there were no beeps coming from the board. I left it on for a while and after a few restarts it sprang back to life, complaining about RAM not being found, tho it was installed. I removed the ram and used contact cleaner both on the ram slot and the ram itself. It found the ram. But the cold start issues kept returning, until i cleaned the ATX power plug and socket on the board with contact cleaner too. i guess they were tarnished enough to sometimes not make a good enough contact for delivering power reliably. Another possible option of what it might be that doesn't let your socket 7 board start?
If I had the other caps in stock I probably would replace them but to be honest I'm not convinced that's the problem. I do need to order some for another project so for the few £ it costs I might just get them for this board too.
Check voltages on regulators, I have a very similar board 1994, and there are some really beefy low profile heatsinks on those regulators. Oh, do not use a MMX Intel CPU. Get a Pentium 75/100 from 1993. Also use EDO ram instead of SD, Gosh I remember 32mb EDO ram in 1997 costing an arm or leg back then.
You could email it to me. Casualretrogamer@outlook.com I'm fairly sure my board is dead though, but if you didn't mind sending the picture I'll give it one more go.
You are putting the heatsink wrong, it must be displaced in the other direction, that will not make it start, but the compulsive obsessives can sleep better.
Only just started watching but I know exactly how that capacitor was removed. Something pushed into a drive bay took it clean off probably. Ask me how I know 🤐
@@CRG Yeah, I 'done messed up' as they say. Sorry you couldn't get this board working. Not sure what else to suggest other than go over it again a few times and see what gives.
@@rasz Yeah, true. To be fair I have a few boards like that. What made me think it was the drive bays is that it's always that same corner of the board that loses a capacitor.
Just a few other quick things to test then yes it might get put aside for a while. Is sometimes better to walk away from something like this then come at it with a fresh set of eyes later.
I sometimes wonder what people who remove components from motherboards are hoping to accomplish other than to thoroughly annoy someone else in the future. "Oh yes, these VRM heatsinks and jumper bridges will come in handy, it's not as if they're already present on every other motherboard which requires them." - Wankers.
Order a POST card for it to see where in the POST it's failing at. This way you can narrow it down to what part of the board is failing.
I actually have one of these and it never dawned one to try it. Great idea though, I'll go try it now and let you know.
No post codes. You can see the reset working but it just sits there after that doing very little. Clock and Frame lights are lit, not sure what frame means to be fair. Voltages all check OK too.
@@CRG I have a 286 board that does the same thing. Means the board is not starting. Try re-flashing the BIOS and then check for voltages and clock signals on the CPU and various ICs. Also, check to see if the voltage regulators are working. Maybe the CPU isn't getting power due to a faulty regulator.
No post code usually means the cpu isn’t able to execute bios code.
Is the chipset getting hot? You might want to use ipa to identity if it’s too hot. If so, the chipset might be faulty.
Power regulators might definitely be broken. Especially when there’s no heat sink attached. It’s a good sign!
Good luck!
@@Inject0r The chipset IC to the left of the CPU socket gets screaming hot fairly quickly (after about 30 seconds) so I'm fairly sure that's where the problem lies. There is absolutely no activity on an address or data lines so for now I've conclude its dead. Time to move onto the next project box and hopefully with a bit more luck.
I made an offer on a Gigabyte GA-586HX which was "broken", it looked perfect the only issue was a lack of a BIOS chip and missing Dallas battery. Usually, prefect boards are dead but I wanted this board (even if it was dead) as I had one briefly back in 1996 (which was DOA) and exchanged it for a different board. So I flashed a BIOS image onto a 27c010 and inserted the battery expecting it not to boot at all, but it booted! Got lucky that time.
Well, a good approach is always start with checking voltages after fixing all obvious places with visible damage. In this case good idea would be to check what voltage you actually do get supplied to CPU, to chipset ICs, to PCI and to ISA slots. Refer to widely available docs on the Internet with info on what CPU socket, ICs and slots pins to check. Next point - obey KISS principle. You don't need memory or video card to check if MB is alive. Bare minimum is CPU (best idea is to use some common midrange one - like iPentium 120 or even Pentium 90 for this case) and PC speaker to be able to hear beeps. Even better would be to have ISA post card on hand to see if CPU is getting reset/running or not. For "voltages ok but no CPU activity" case first places to check are PowerOK and PowerOnReset circuits followed by checking BIOS IC contents. Yet another good idea for this MB would be to reflow all pins on IC that you were re-soldering some damages pins. It even might be reasonable to desolder this IC completely using a lot of flux and air gun just to check the condition of traces that are under the IC - you might have some more damage there as well.
Thanks for the detailed response. Some good tips in there and I will go and check voltages to be sure but certainly at the PCI / ISA slots along with various chips the voltages all look good. Didn't check the CPU but will do.
I've since also tried a post card which shows the reset line working fine but then just sits idle. No post codes etc so my thinking is its something to do with the BIOS. I've checked the rom and it looks fine but also tried a BIOS image I found online for this board, same result.
Keep the ideas coming though, always grateful for any help or advice. I'm not keen on removing that chip totally since my soldering skills may not be up to replacing it again, just want to rule out everything else first.
@@CRG Look up "How to troubleshoot your defective 386/486 motherboard with an oscilloscope" topic on the EEVBlog forum where I helped feipoa (true vogons legend that lad) with few dead boards, covers wide range of diagnostic steps. You do have a Hantek LA so diagnosing whats wrong shouldnt be difficult (just tedious). Start by looking at the Bios address/data lines if its being accessed at all.
@@rasz I'll take a quick look but I've found another issue this evening that might mean curtains for the board.
@@CRG s7 boards were so simple there is almost nothing that cant be repaired :) If you need step by step help just post on eevblog in Electronics »Repair
@@rasz I've found evidence to suggest there are faults on the internal layers of the board. Discovered a missing 5v on one of the transistors bottom right but if I pull or push the component or even just flex the board it'll suddenly come back. Not much I can do to fix that and if there's that one internal problem there's most likely others.
Hi, nice channel! I have as many boards like yours awaiting repair, sadly with the same symptoms ... it's a little frustrating when it's not showing signs of life. Do not give up!
Superb channel buddy! Discovered today and subbed. Love the 486 Pcchips M912 build. Got the same board in a later revision. But only 128k cache with 16MB RAM and DX4-100. VLB SCSI and Primax Soundstorm GUS Clone and also an S3 VLB VGA with 2 MB. After watching your video i feel tempted to add a CT1600 to test if they knock each other out too on my board. Will keep you updated.
Thanks for the kind words and for subbing.
I've since got the issue with the GUS sorted. Well mostly as the GUS is muting it's line in randomly but easy to sort with a simple command. If you do try the ct1600 alongside please let me know how you get on. I have a DX4 100 system to build at some point in the future, was tempted to drop that chip in the PC Chips build but I'm happen enough with the DX2 66 in there.
You answered your question at 18:35 at the start of the video. But we've all done and will most certainly do it again, many times over :)
Yeah don't be buying crap at 2am 😂. Not totally given up on this one yet, still a couple of things to try.
That would be a nice little Triton chipset board. Could be a stupid or already answered/tried question: are the CPU Vcore, I/O, BIOS ROM and DRAM voltage rails read nominal? Could be the person before you used it for a long time without the LDO regulator heatsinks. Does it beep the DRAM error code when there's no RAM installed?
No beeps, the board is dead on the post card. Voltage rails look OK but I have found another potential issue that could spell the end of the board.
That's too bad. Is there any activity on the pins of the BIOS ROM?
@@chris-tal going to check that later to be sure but I'm fairly sure there is internal damage. Found a missing 5v with no signs of damage. If you push or pull the component or even just flex the board it'll come back. Doesn't bode well for fixing it.
@@CRG You could also check the clock generation circuitry, but this board flexing thing sounds bad enough already.
@@chris-tal check the 14.(odd) MHz crystal on board which is fine. Not sure where the system clock is generated. Need to pull the datasheet for the chipset but going to check the bios address and data lines first.
Where you repaired the track on the underside, I noticed some bent pins in that row and also looked like it was shorting to the next pin.
Thanks, I'll double check this but didn't see any shorts initially. Might have missed something though.
My feeling is that the lack of boot isn't due to damage, but configuration issue.
It's possible the CPU isn't supported. I would have expected at least a beep otherwise.
Just discovered your channel thanks to this video. Awesome! Looking forward for more :)
That has crossed my mind too, that the processor might just not be compatible. I'll order up a Pentium 75 (or something similar) just to try. Always good to have more in the collection anyway.
Plenty more to come on the channel so thanks for watching and please stick around.
@@CRG It's hard to resist the appeal of collecting ;)
I've had similar luck getting socket 7 boards to come back to life.
I've not totally given up yet, still a few things to try but it isn't looking good for this board.
It might be worth reprograming the BIOS chip from a good file. It only needs one bit to flip with age to corrupt it.....
Well you can actually use a 2.8V CPU. You have to configure it to "split voltage" operation :)
Also, I think the way you've installed the EDO ram is wrong (it should be in pairs in two slots next to one another), but I doubt it'd prevent you_r board from POSTing.
If you look at the board the edo slots are labelled 0101 that's why I installed the ram as I did. Both are in slots labelled 0.
But yes that's highly unlikely anything to do with why it doesn't boot.
I've since tried the cyrix cpu at 2.8 volts with the split voltage but same result :(
@@CRG Yeah I noticed that but I think they meant slot N°0 of bank 0, slot N°1 of bank 0, etc.
I've never seen a pentium board with a different slot layout than that (but this could be the exception nonetheless, who knows ?)
@@DxDeksor you might be correct but regardless its not the issue. Using a test card the board seems to get stuck after reset. Need to do a bit more reading on the boot process to understand what should come next.
@@CRG which post code exactly ? And which bios ?
@@DxDeksor no post codes. You can see the reset flash then it just hangs. Power rails are all good. Clock and frame leds are also lit but admittedly I'm not sure what frame is.
If the board was dropped you may have cracked solder joints on the bottom of the board.
Ive been over the bottom of the board with my magnifying glass and don't see any. A complete relow will probably be one of the next things I try although it'll be difficult on the smd stuff.
I know I am very late to the party watching this one, but is it possible you need to briefly jumper a power "sw" header on the board to in effect turn it on? I have not looked up this board to check but that is sometimes a thing with older boards I have worked on.
I don't recall anything like that in the manual, well what I had of it. If I get the chance I'll take another look at it but I'm fairly sure the issue on this board is down to a fault in the chipset.
Have you tried to reprogram the BIOS EEPROM with your TL866? (providing you can download it somewhere)
I myself had some luck reviving some dead SS7 boards just by doing that.
Yep I've since tried that. Found a bios online although in a bit dubious if it's correct or not but tried it anyway and no difference. The original bios is saved and to be honest the 2 files appear identical so the original was probably fine.
Even if the other capacitors look good, they might be "dry" and need to reform, by leaving the board on for a while. But i guess that can't be done safely without the missing heatsinks. Or replace the other capacitors too. When in doubt, change capacitors :D But changing throughhole capacitors on multi layer boards is no fun... Needs lots of flux..and then some more flux :p
I doubt they are dry, the board is not THAT old...
@@8bitbubsy Well, with "dry" i mean, the electrolyte inside has to be respread and reactivated again; and with the board coming from the late 90's, it's actually more than 20 years old now. Also, if it just sat there without it being powered on, that wouldn't have benefited the capacitors. It doesn't mean it HAS to be the capacitors, but it's an option.
I recently had a socket 370 Mainboard that showed similar behaviour, with fans and peripherals like floppy and CD-drives initializing, but the screen stayed blank and there were no beeps coming from the board. I left it on for a while and after a few restarts it sprang back to life, complaining about RAM not being found, tho it was installed. I removed the ram and used contact cleaner both on the ram slot and the ram itself. It found the ram. But the cold start issues kept returning, until i cleaned the ATX power plug and socket on the board with contact cleaner too. i guess they were tarnished enough to sometimes not make a good enough contact for delivering power reliably. Another possible option of what it might be that doesn't let your socket 7 board start?
@@Asriazh Possibly...
If I had the other caps in stock I probably would replace them but to be honest I'm not convinced that's the problem. I do need to order some for another project so for the few £ it costs I might just get them for this board too.
Hi sir, what kind of bios reader you use for award 586. I got few working board but some bios seems faulty . Pls advice me. Thanks
you seem to have a knack to find stuff nobody knows about and it's hard to find documentation on xD
It's just my dumb luck 😆
Check voltages on regulators, I have a very similar board 1994, and there are some really beefy low profile heatsinks on those regulators. Oh, do not use a MMX Intel CPU. Get a Pentium 75/100 from 1993. Also use EDO ram instead of SD, Gosh I remember 32mb EDO ram in 1997 costing an arm or leg back then.
This board is very tricky to setup. I have the exact same board with working jumper setups for MMX 233. If I take a pic how do I get it to you?
You could email it to me.
Casualretrogamer@outlook.com
I'm fairly sure my board is dead though, but if you didn't mind sending the picture I'll give it one more go.
You are putting the heatsink wrong, it must be displaced in the other direction, that will not make it start, but the compulsive obsessives can sleep better.
At this stage I'd try anything to make it boot 🤣
Check the power supply of the cpu and the clock freqvency of them, if ok them use a post diagnose card.
do you have other socket 7 cpu you can try?
Unfortunately not, just those 2. The Pentium is a good chip though. I should probably get another few models just for testing.
@@CRG I would try something lower end like 75-150 MHz just to be sure. Motherboard might act like a dead one if cpu is not supported
@@mrvellu easy enough to test, take the cpu out and see if it beeps..
Use a stanly knife blade to split the pins and flux and wick to remove the bridges
I used my craft knife to seperate them and yes flux and braid cleaned up the mess.
total hardware 99 has all manuals and jumper settings
Thanks I'll take a look.
Tried that site but it doesn't seem to have a listing for the AVB55C. If you were able to find it I'd be most grateful if you could post a link.
Its probably been said but I'm sure that board doesn't support MMX CPU's
What a beautiful, compact board. Shame it's dead.
Only just started watching but I know exactly how that capacitor was removed. Something pushed into a drive bay took it clean off probably. Ask me how I know 🤐
Speaking from experience?
We've all done some silly things with hardware over the years.
@@CRG Yeah, I 'done messed up' as they say. Sorry you couldn't get this board working. Not sure what else to suggest other than go over it again a few times and see what gives.
to me it looks like the board was tossed into the trash pile
@@rasz Yeah, true. To be fair I have a few boards like that. What made me think it was the drive bays is that it's always that same corner of the board that loses a capacitor.
How disappointing after all that fiddly work. Mmmm, maybe just put it aside and let the 'little grey cells' work on it for a while. 👍😊
Just a few other quick things to test then yes it might get put aside for a while. Is sometimes better to walk away from something like this then come at it with a fresh set of eyes later.
@@CRG Works almost every time.
I sometimes wonder what people who remove components from motherboards are hoping to accomplish other than to thoroughly annoy someone else in the future.
"Oh yes, these VRM heatsinks and jumper bridges will come in handy, it's not as if they're already present on every other motherboard which requires them."
- Wankers.
find a good quality picture and copy the rest of the jumpers position
use a diagnose card
I tried that and there is no activity. Fairly sure the board is just dead.
just recycle it, i guess its way beyond repair and can't be fixed.