Back at this.

If I use some epoxy to insulate the burnt area would be the same?
I ordered some solder mask but it'll take 2 months to get here.

If I add a fuse on that line to avoid future issues, would it be a good idea?

You can always pick up some clear nail polish I've used that many times and it's cheap if you take the bottle from your wife like I did.

Nexxen wrote on 2021-06-29, 09:01:

Back at this.

If I use some epoxy to insulate the burnt area would be the same?

Yes, it's ok. Personally sometimes I use such thing, I don't know how to explain in English though 😀
Maybe it's something like a nail polish like chrismeyer6 said, but for specific usage.

The sticker says (google's translation):
"Varnish L-88 for drawing printed circuit boards, painting light bulbs and models . Drying time 20 minutes. Easy to wash off with nitro thinner"

Roman555 wrote on 2021-06-29, 15:31:

Yes, it's ok. Personally sometimes I use such thing, I don't know how to explain in English though :-) https://images.ua.prom.st […]
Show full quote

Nexxen wrote on 2021-06-29, 09:01:

Back at this.

If I use some epoxy to insulate the burnt area would be the same?

Yes, it's ok. Personally sometimes I use such thing, I don't know how to explain in English though 😀

The sticker says (google's translation):
"Varnish L-88 for drawing printed circuit boards, painting light bulbs and models . Drying time 20 minutes. Easy to wash off with nitro thinner"

YES!! 😀

Thanks Roman!

I used some epoxy and the result is good.

Now, I wanted to test the board before soldering anything,
and the voltages for the caps and USB + LPT are, for a live board, 2.70V.

There is V going to USB and LPT.
Trace to LPT is 2.70.

There must be some other connection I can't see.
Correct me if wrong.

Tried to install W2K, RTM and SP4 but it reboots at "installing devices" (or similar), right after booting to HD.

Probably there's a driver I need to install at the beginning, when asked to press F6.

Never had trouble with W2K on the rev 1.0 of this board (mine is currently dual booting XP SP3 and DOS) but I guess it does depend on what cards you have inserted. Are you running the latest BIOS version?

Nexxen wrote on 2021-07-02, 12:00:

I used some epoxy and the result is good. […]
Show full quote

I used some epoxy and the result is good.

Now, I wanted to test the board before soldering anything,
and the voltages for the caps and USB + LPT are, for a live board, 2.70V.

There is V going to USB and LPT.
Trace to LPT is 2.70.

There must be some other connection I can't see.
Correct me if wrong.

It should be 5V (all voltage measurements are relatively to GND).
If it's not - check using an ohmmeter the wire between the fuse FS1 and this point. Maybe the via is broken and has high resistance. Or FS1 could be broken.
Also check using an ohmmeter resistance between this point and GND.
Obviously an ohmmeter should be using when the power cord is disconnected.

gca wrote on 2021-07-02, 23:39:

Never had trouble with W2K on the rev 1.0 of this board (mine is currently dual booting XP SP3 and DOS) but I guess it does depend on what cards you have inserted. Are you running the latest BIOS version?

The bare minimum. Only graphics card could be the issue but I never had issues with other builds.
This board could have some damage that W98se doesn't pick up while 2K does?

BIOS 1.3, max for this model i think.

Roman555 wrote on 2021-07-03, 06:53:

It should be 5V (all voltage measurements are relatively to GND). If it's not - check using an ohmmeter the wire between the fu […]
Show full quote

Nexxen wrote on 2021-07-02, 12:00:

I used some epoxy and the result is good. […]
Show full quote

I used some epoxy and the result is good.

Now, I wanted to test the board before soldering anything,
and the voltages for the caps and USB + LPT are, for a live board, 2.70V.

There is V going to USB and LPT.
Trace to LPT is 2.70.

There must be some other connection I can't see.
Correct me if wrong.

It should be 5V (all voltage measurements are relatively to GND).
If it's not - check using an ohmmeter the wire between the fuse FS1 and this point. Maybe the via is broken and has high resistance. Or FS1 could be broken.
Also check using an ohmmeter resistance between this point and GND.
Obviously an ohmmeter should be using when the power cord is disconnected.

No power:

FS1 to GND 150 ohms
Fs1 has continuity (free flow), but also has continuity with GND.
Gnd to point on pic is "no reading".

Power:

FS1 is 5.08V
Cap in the pic has 2.80V <----------- could it be bad?
Gnd to L3 (as on pic) is 2.50V

I haven't soldered anything yet, L3 is still cut.
Just put some epoxy to fill the hole and insulate the trace that runs below it.

***

AFter checking to find the origin of the V, I found that behind the cap there is a RESISTOR R6 - 471
Reading is 280K Ohms
Live is - 287k Ohms

reading is fs1 to R6 3.66V (live board)
through r6 3.66 to 0.62
non to fs1 end to gnd 2.75

I'll have to remove the cap ...

Nexxen wrote on 2021-07-03, 09:49:

No power: […]
Show full quote

No power:

FS1 to GND 150 ohms
Fs1 has continuity (free flow), but also has continuity with GND.
Gnd to point on pic is "no reading".

Power:

FS1 is 5.08V
Cap in the pic has 2.80V <----------- could it be bad?
Gnd to L3 (as on pic) is 2.50V

Power to USB goes this way:
PSU +5V -> FS1 -> L3 -> USB +5V

The schematic would look like this:

1+5v >--[FS1]-----[L3]---+----> +5v USB
2                        |+
3                       === CAP
4                        |
5                       GND

No power:

FS1 to GND 150 ohms ===== It's maybe power supply (PSU) output impedance
Fs1 has continuity (free flow) ===== ok
Gnd to point on pic is "no reading". ===== the bottom pad of L3 which designated by red arrow? - IMO, it should be the same that FS1 has, because they definitely should be connected.

Power:

FS1 is 5.08V ===== Ok
Cap in the pic has 2.80V <----------- could it be bad? ===== don't know
Gnd to L3 (as on pic) is 2.50V ===== don't know

Thanks for all the help.

I'll solder a wire over L3 to see what happens then.
First I'm going to desolder the cap and post a pic for posterity.

I soldered everything back together.

L3 connected to +5V makes usb work 100%
Have to test LPT but I doubt it's not gonna work.

LAst thing, if I put a replacement smd what could it be for the values?
I guess I am done with this unless it burns again.

Now I have to find what's wrong with W2K not installing. 😀

Flashed to bios ver F6 but keeps rebooting after files are copied to hd.
As soon as the loading logo appears it reboots after a few seconds or immediately.

Ubuntu doesn't load, hangs after casper dots and reboots.

Using an amd k6-2/500.
No cards, ram is known good.
AGP card 8mb nvidia 128

Nexxen wrote on 2021-07-03, 13:37:

I soldered everything back together. […]
Show full quote

I soldered everything back together.

L3 connected to +5V makes usb work 100%
Have to test LPT but I doubt it's not gonna work.

LAst thing, if I put a replacement smd what could it be for the values?
I guess I am done with this unless it burns again.

It's difficult to say. Everything is IMO.
I would pick something similar from any "boards for parts".
Ferrite bead with size 0805 for current maybe 0.8-1A because "USB 1.0 and 2.0 standard downstream port, delivers up to 500 mA"

P.S. Is Ubuntu old enough and 32bit? Have you tried Win98 yet? What about memtest86 - does it hang too?

Roman555 wrote on 2021-07-03, 20:03:

It's difficult to say. Everything is IMO. I would pick something similar from any "boards for parts". Ferrite bead with size 0 […]
Show full quote

Nexxen wrote on 2021-07-03, 13:37:

I soldered everything back together. […]
Show full quote

I soldered everything back together.

L3 connected to +5V makes usb work 100%
Have to test LPT but I doubt it's not gonna work.

LAst thing, if I put a replacement smd what could it be for the values?
I guess I am done with this unless it burns again.

It's difficult to say. Everything is IMO.
I would pick something similar from any "boards for parts".
Ferrite bead with size 0805 for current maybe 0.8-1A because "USB 1.0 and 2.0 standard downstream port, delivers up to 500 mA"

P.S. Is Ubuntu old enough and 32bit? Have you tried Win98 yet? What about memtest86 - does it hang too?

It reboots with all x86 ubuntu releases up to 9.xx (didn't burn 10.xx). Memtest works though.
Win 2k/xp hang at what looks like a driver issue.

Win 98se only loads in safe mode, while I previously had everything ok.
I'll remove the soldered wires tomorrow to check if that's the issue.

Nothing changed. Just usb not working.

Issue is with some peripheral and drivers. Safe mode works, others don't.

I was having issues with K6-2/III
Switched to P233 MMX and it actually works fine with FSB 66.

Could be that K6 and 100 mhz fsb are at odds with this board? Going to install W2K and see if it is that.
Possibly even Ram density.
Next step is to try K6 @ 66.

EDit: W2K installed flawlessly. No issues.
Gonna go for other cpus and check where it actually gets unstable.
I have all the K6 line to go through 😀