ediflorianUS wrote on 2023-03-06, 15:00:

did not read all , but did you change keyboard? seems a kb issue or at least kb input issue somewhere on the line of KB....

Problems are also without keyboard connected so actually it doesn't matter I fear.

rasz_pl wrote on 2023-03-06, 14:16:

all behind the coil […]
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Nemo1985 wrote on 2023-03-06, 12:49:

That's a point, which caps? The one near the coil wire?

all behind the coil

Nemo1985 wrote on 2023-03-06, 12:49:

Measure... i'm sorry but about it i'm quite dumb, can you show me where I have to use the tips of the meter?

https://en.wikipedia.org/wiki/PS/2_port
pins 1 3 4 5
also pins 1 5 all the way to superIO chip pins

Ok continuity mode it beeps on pins 3, it should be ok.
Resistance resistance between pin 4 and ground is 0.535 fixed value.
Resistance resistance between pin 1 and ground is 1.4xx and increase, same goes for pin 5.
About continuity between super io chip pins and pin 1 or 5, I got no beeps. So no continuity

TrashPanda wrote on 2023-03-06, 14:35:

bogdanpaulb wrote on 2023-03-06, 14:25:

Might be the pic , but that trace looks interrupted by corrosion .

They certainly dont look right and since they look like they are going to and from the IDE sockets they might be worth checking for continuity.

Those traces are not in good conditions but to a first glance they are connected to the secondary ide port. If I connect an hard drive to the primary port it gets recognized right from the bios.

bogdanpaulb wrote on 2023-03-06, 14:25:

Might be the pic , but that trace looks interrupted by corrosion .

I took another picture, it doesn't seem cut but some corrosion is going here?

it should be something else then. (don't worry about corrosion if trace is connected from A-B) just clean with contact cleaner and some WD40 silicone. Battery is 3V is it at least 2.9V? it may be a ground problem from kb or somewhere when it post's and checks things , then it start's peeping (seen youtube video). Try disable-ing everything in bios if you can enter , pull hdd and leave floppy only.... (use different ram stick in first slot from CPU).

ediflorianUS wrote on 2023-03-06, 15:44:

it should be something else then. (don't worry about corrosion if trace is connected from A-B) just clean with contact cleaner and some WD40 silicone. Battery is 3V is it at least 2.9V? it may be a ground problem from kb or somewhere when it post's and checks things , then it start's peeping (seen youtube video). Try disable-ing everything in bios if you can enter , pull hdd and leave floppy only.... (use different ram stick in first slot from CPU).

Battery (when installed) is full.
Also to my knowledge memory slots should be populated from the farthest one because the signal bounce back otherwise.
Anyway I did a try, no I can't navigate the bios no matter if I use a ps2 keyboard or a usb one, initially with the usb I was able to navigate the bios but now it doesn't work.

I do not recommend using the MB without battery , it's ok to start enter bios , then shoot down and plug in the battery. Many new'er systems would not even boot if you had no 2.95V on battery.
Best to see manual where the nr1 memory slot is , it's usually the one from CPU. If you really think it's a chip/chipset and not a short somewhere at PS2 plug , you can always Hot-Iron cottons setting , about 10-15min the chipset for rejoining the BGA balls , or silicone defects inside the chip. (worked well on GPU that nvidia screw-ed up 8700m series). Reflow is not always the best solution for chips. = This operation is last case scenario , your's starts (MB/chipset) so it should be some other little thing . if it's a chip problem , or vrm(mosfet) it usually heats up or no post at all. If you have letcon solderhead) you can try re-do the connection of PS2 plug on MB, may be a cracked solder joining , and check the plug or USB plug for metal residue inside , can do crazy stuff with MB (seen it happen far more often than you may imagine even seen material logged under chipsets). contact cleaner cleans anything hurts nothing. Don't forget to be 100% sure your PSU is working ok, & power system unit is grounded , and home is grounded.

BTW , I found the manual , checking it now.

Filters on the keyb lines?
Check all smd that go to keyboard/ps2. I once had a dead component, not blown, not discoloured.

btw just occurred to me , try re-mounting the cpu , clean well under the MB (then remount). It sometimes helps. (as mentioned first s-dimm is the one from the CPU)

Try setting up power jumpers all to on USBPWR01 to 2-3 enabled , USBPWR56 to 2-3 enabled, KBPWR 12 Enabled , if same , try different combination (default , default+dissabled)
Voltage I/O settings 3.4 -2+3 , or 3.3 - 1+2

also try manual DSW external frequency settings , by the ram speed (not sure what your ram or cpu is). - see manual page 22

Nexxen wrote on 2023-03-06, 16:14:

Filters on the keyb lines?
Check all smd that go to keyboard/ps2. I once had a dead component, not blown, not discoloured.

Even without keyboard installed?

yeah, those traces don't look very healthy.
Corroded traces can not be trusted.

Nemo1985 wrote on 2023-03-06, 15:26:

Ok continuity mode it beeps on pins 3, it should be ok.
Resistance resistance between pin 4 and ground is 0.535 fixed value.

https://www.calculator.net/ohms-law-calculato … =watt&x=47&y=15
measure again in _resistance mode_, might be blown ps2 port?

Nemo1985 wrote on 2023-03-06, 15:26:

About continuity between super io chip pins and pin 1 or 5, I got no beeps. So no continuity

there must be continuity between pins 1 5 and https://pdf1.alldatasheet.com/datasheet-pdf/v … ND/W83627G.html pins
KCLK 62
KDAT 63

also that corrosion, if its in one spot it might be somewhere else under a chip

weedeewee wrote on 2023-03-06, 16:18:

yeah, those traces don't look very healthy.
Corroded traces can not be trusted.

I edited my last post(check there) , I had some corrosion on my 486 and most of it cleaned off , traces were ok , I did have to fix 1 trace , put some soldering there and never looked back.

Try settings your FSB to 66 manually (cpu is 66mhz fsb), you have, it seems, some corrosion on your Parallel port....

In the end it may be a bad (dry) - or going bad capacitor , that you can only measure that with analogue ohm meter or ESR meter.

rasz_pl wrote on 2023-03-06, 16:25:

https://www.calculator.net/ohms-law-calculato … =watt&x=47&y=15 measure again in _resistance mode_, might be blown ps2 port? […]
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Nemo1985 wrote on 2023-03-06, 15:26:

Ok continuity mode it beeps on pins 3, it should be ok.
Resistance resistance between pin 4 and ground is 0.535 fixed value.

https://www.calculator.net/ohms-law-calculato … =watt&x=47&y=15
measure again in _resistance mode_, might be blown ps2 port?

Nemo1985 wrote on 2023-03-06, 15:26:

About continuity between super io chip pins and pin 1 or 5, I got no beeps. So no continuity

there must be continuity between pins 1 5 and https://pdf1.alldatasheet.com/datasheet-pdf/v … ND/W83627G.html pins
KCLK 62
KDAT 63

also that corrosion, if its in one spot it might be somewhere else under a chip

Let's see if I did it right:
Resistance pin4 to ground: https://youtu.be/7QS1SPjUz9o
Continuity between pin 1 and i\o (in this video I also show you the beep of when proper continuity is present): https://www.youtube.com/watch?v=smFxTRuoAFY
Continuity between pin 5 and i\o: https://youtu.be/y6s1i2hytz0

Again , can you make a focused pic of that area ? That pin of the resistor pack is not shiny like the rest , that might be corrosion , that trace might also be eaten by corrosion . Can't tell that if the pic is out of focus .

bogdanpaulb wrote on 2023-03-07, 04:46:

Again , can you make a focused pic of that area ? That pin of the resistor pack is not shiny like the rest , that might be corrosion , that trace might also be eaten by corrosion . Can't tell that if the pic is out of focus .

I hope those are ok, that's the best my cellphone camera can do:
https://imgur.com/a/kevcfH2

That looks ok.
Can you cofirm 5V when system is ON for both '1' positions ?
Can you measure '2'3'4'5' ('5' is next to '4' and not the jumper) relative to ground (metal shield of the kb conn) in diode mode(continuity) and specify me the values for both cases when you have 'red ' to ground and 'black' to ground ? ( System OFF , no PSU connected to the board ) .

I would gladly do but apparently the motherboard doesn't turn on now...
Green led is light but when I push the power button it start.
What the hell?
Should I bridge the 2 psu pins and put the 20 pin connector on and see what's blow up?
It doesn't even cut the power, just... doesn't turn on

Then can you do this ? 'Can you measure '2'3'4'5' ('5' is next to '4' and not the jumper) relative to ground (metal shield of the kb conn) in diode mode(continuity) and specify me the values for both cases when you have 'red ' to ground and 'black' to ground ? ( System OFF , no PSU connected to the board )' .

Black to ground:
2: v0,993
3: goes up to v1.9xx and slowly increase
4: went up to v1.812
5: v0.97x slowly decrease

Red to ground:
2: begins from 0,6xx and slowly decrease
3: v0.7xx and slowly decrease
4: v0.753
5: v0.65x and slowly decrease

Out of curiosity should I wait for a final value? Also as ground point I used the pinch on the usb metal plate.
Why doesn't it turns on now? I just used some ipa on the out of focus spots where you needed pictures...
It's like the power button doesn't get the signal

Use a heater(hair drier) on the area where you used ipa . (5~ minutes).
Do you have a soldering iron / any soldering skills ?
Black to ground - you should have nothing ( 1 on the screen same as the leads are not connected to anything ).
Red to ground - ~700 , same value on all 4 ( a few seconds for the value to settle should be enough )

Nemo1985 wrote on 2023-03-07, 07:08:

Black to ground: 2: v0,993 3: goes up to v1.9xx and slowly increase 4: went up to v1.812 5: v0.97x slowly decrease […]
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Black to ground:
2: v0,993
3: goes up to v1.9xx and slowly increase
4: went up to v1.812
5: v0.97x slowly decrease

Red to ground:
2: begins from 0,6xx and slowly decrease
3: v0.7xx and slowly decrease
4: v0.753
5: v0.65x and slowly decrease

This tells me that you have unwanted resistance to ground ( i hope that when you took the measurements you removed the PSU and the KEYBOARD/MOUSE ) most likely due to corrosion (could be a bad super i/o but let's try to eliminate the corrosion factor first ).
I need a perpendicular clear/focused pic of area 1 and a perpendicular and angled clear/focused pic of area 2 (remove the jumper for the pic).
Also that trace looks bad and has to be addressed.

Yes when I took the measures I was near to my daily pc (to write the values) so the motherboard was fully disconnected.
About the values I don't know what to say, I'm quite confident I took them right (I did twice to be sure).
I have no soldering skills (but I have the stuff), if we can locate the issue I have a person who can repair it.
Area 1 and area 2 are near the ps2 ports right?

The bad trace: to my eyes it has corrosion but isn't cut. How can it be addressed I could try to tin it but I will probably do more harm than good.

Thank you for your kind help

Area 1 is the super i/o chip near the bottom next to the last pci connector , 2 is with the ps2 ports .
You can leave the trace but that one looks bad and i had cases of the protective layer being above cooper that was already eaten by corrosion . You can scrape it on the surface with a sharp tool just to be sure that you still have cooper underneath. And if it checks out use a protective lacquer / nail polish / whatever you have at hand and does not react with cooper .