look closely for screwdriver marks on the chipsets green interposer
ram looks like the fully compatible part, and its Wilk Electronic at that nice (Polska gurom)

rasz_pl wrote on 2026-04-08, 03:02:

look closely for screwdriver marks on the chipsets green interposer
ram looks like the fully compatible part, and its Wilk Electronic at that nice (Polska gurom)

Hey raz a pleasure to read you, I bought this motherboard from Poland nonetheless.
I did some further tests:
Voltage & Continuity Measurements:
1. Power Rail (VCC Pin 4 to GND Pin 3):
Keyboard Port: 4.91V (Stable).

2. Data & Clock Lines (Measured from underneath):
Keyboard Port (PC On): Both Data (Pin 1) and Clock (Pin 5) show a stable 4.9V.
Mouse Port (PC Off): Resistance between Pin 1/Pin 5 and GND is approximately 15kΩ.

3. Grounding:
Resistance between Pin 3 (GND) and the port metal casing is 0.2Ω - 0.3Ω on both ports.

Continuity:

There isn't between the L1-F1 but there is between L2-F2
If I try to connect a mouse and (one of the few time that it boots fine detect with cute mouse it says no mouse found and then hang before get back to the prompt).

The ram I suppose are not completely detected because they are double side?
The 64mb which has just one side populated is fully detected.

I took some pictures:
https://drive.google.com/file/d/1BrIMxk457bl8 … iew?usp=sharing

In your opinion those stability issues are caused from the lack of the heatsink on the bx chipset? It gets very hot even just after some seconds the motherboard is turned on, I've put a heatsink on it but it may have been damaged from the previous owner.

Nemo1985 wrote on 2026-04-07, 22:09:

Hi, I recently bought this motherboard and the ps2 keyboard and mouse ports don't work.

It’s not complicated at all if you have a soldering iron.
Typically, PS/2 interfaces are powered via a ferrite bead/fuse/ 0-ohm resistor, and a 0.1 μF capacitor connected to ground.
If +5V is already present at the connector itself, then that’s not the problem.

Signal circuits
- Ferrite beads are typically placed immediately after the connector (any type will do for this application; the main thing is that the resistance is less than 1 ohm)
- Capacitors to ground. 100–470 pF with a COG/NP0 dielectric. Often, this is an assembly of 4 capacitors. On Asus boards back then, they often leaked current, and there is a recommendation to simply remove them. The same problem may exist on your Abit board.
- Push-up resistors from the power supply, 4.7–10 kΩ (often an assembly of 4 resistors in a single package)
- Series resistors of about 1 kΩ near the SIO.
None of these are exclusive components, and they can be sourced from any donor.

Thank you for the tip shevalier.
I changed one bloody capacitor the one marked in the picture and now the keyboard works fine, mouse is still not detected, though.

My board is weird because it uses only two types of capacitors:
v6.3 1500uf for: red, yellow and blue
v16 200uf for the green.

I also measured the old jackon capacitor: 1389uf, vloss 2,4%, esr 0.16.
It didn't seem so bad?

What's the next step should I go for a complete recap?
I have polymer caps x-con which are rated for 1000uf v6.3 will they work fine?

Edit: I changed some more caps, I still have the old ones on:
4 near the agp slot
3 near the atx connector
9 around the cpu.
The mouse is still not detected but the ps2 keyboard works fine.
If I connect the drive to the integrated ide ports it hangs on the post screen after the bios most of the times, if I connect the drive to the highpoint it boots fine and I was able to run some benchmarks.
With NSSI I noticed that it hangs for a minute on gathering pnp.
The bx chipset is still hot like hell, I think the central parts reach more than 60°C I can't keep the finger on for more than few seconds.

Should I go ahead? Which one I should change now?

Nemo1985 wrote on 2026-04-08, 10:43:

I also measured the old jackon capacitor: 1389uf, vloss 2,4%, esr 0.16.
It didn't seem so bad?

ESR should be near 15 mOhm, i.e. ten time less

Nemo1985 wrote on 2026-04-08, 10:43:

What's the next step should I go for a complete recap?
I have polymer caps x-con which are rated for 1000uf v6.3 will they work fine?

Great choice.
Even a 560 μF polymer capacitor would be sufficient for the power requirements of that time.

I've completed the recap of the capacitors marked with the red star.

The ps2 mouse ports still doesn't work.
The integrated ide ports are finicky and make the system unable to boot but the raid controller works fine (and system is apparently stable).
Before go ahead with a useless recap, do you think that two issues could be solved by changing the remaining caps or should I focus on something else?
I feel that the ide problem are due to the southbridge, while the ps2 mouse port can have some other issue that honestly I haven't the knowledge to troubleshoot.

I'm no expert but I don't think a recap will solve the ps/2 problem. But it could solve the stability with the IDE ports.

Just did a complete recap of a SS7 board with all kinds of hang and other stability problems. The recap solved all those problems.

Did you reflash the BIOS already? Could sometimes solve some issues as well. Also I had a ps/2 mouse before with very tiny pins which didn't make good contact and had similar problems with mouse not being detected. Instead of another mouse I soldered a new ps/2 connector on the board as the old one was a bit worn out.

Yoghoo wrote on 2026-04-11, 22:36:

I'm no expert but I don't think a recap will solve the ps/2 problem. But it could solve the stability with the IDE ports.

Just did a complete recap of a SS7 board with all kinds of hang and other stability problems. The recap solved all those problems.

Did you reflash the BIOS already? Could sometimes solve some issues as well. Also I had a ps/2 mouse before with very tiny pins which didn't make good contact and had similar problems with mouse not being detected. Instead of another mouse I soldered a new ps/2 connector on the board as the old one was a bit worn out.

Reflash the bios (with a eproom writer) was the first thing I did. Actually I can't deny that change the first capacitor resurrected the keyboard ps2 port, but I agree that the the mouse seems a different story. That being said I think it's not the connector the issue, it's probably on some of those small components as shevalier suggested, but unlucky without precise instructions I wouldn't know how to deal with them.

those are all symptoms of ripped off heatsink damaging balls under chipset 🙁 I hope im wrong

Nemo1985 wrote on 2026-04-11, 22:06:

and system is apparently stable

The system cannot be stable because you haven’t replaced the capacitors near the CPU’s VRM.
It’s strange that it boots at all, given that the capacitors’ ESR is more than ten times higher.
And you must replace the capacitor on the +3.3V line closest to the southern bridge.

I’ve already written to you about the PS/2 ports.
To start with, locate the 4-capacitor array connecting the interface signal lines to grownd and remove it.
If this doesn’t solve the problem, simply measure the resistance of the resistor arrays and ferrite beads on the signal lines from the port to the SIO chip.
There is most likely a crack in the solder joint or a brocken component.
Sketch out a diagram on paper, something like: Keyboard Clock – Resistor 1 – Resistor 2 – Pin X of the SIO chip.
And everything will become much clearer to you.
The resistance of all four lines (keyboard clock + data and mouse clock + data) must be measured in all directions using a multimeter and found to be exactly the same
https://commons.wikimedia.org/wiki/File:PS2_c … %C2%B00054b.jpg

PS You're lucky that one of the ports isn't working at all.
On my CUBX-L, this arrey of four capacitors is located in a very inconvenient spot.
After disassembly, it turned out that these capacitors already had an ohmic resistance of 47–12 kΩ.
Symptoms: works perfectly for a year, then goes haywire for two days, to the point where the system won’t even boot.
I replace the keyboard—it works perfectly for another six months.
That’s why I didn’t want to mess with it, but in the end, I had to force myself to do it.

shevalier wrote on 2026-04-12, 07:13:

The system cannot be stable because you haven’t replaced the capacitors near the CPU’s VRM. It’s strange that it boots at all, g […]
Show full quote

Nemo1985 wrote on 2026-04-11, 22:06:

and system is apparently stable

The system cannot be stable because you haven’t replaced the capacitors near the CPU’s VRM.
It’s strange that it boots at all, given that the capacitors’ ESR is more than ten times higher.
And you must replace the capacitor on the +3.3V line closest to the southern bridge.

I’ve already written to you about the PS/2 ports.
[...]

Thank you for your patience, I will do as you advice and report back!

Nemo1985 wrote on 2026-04-12, 12:26:

I will di as you advice and report back!

???
First of all, check the resistance between the data/clock pin and grownd directly at the connector.
PS. Those were really sturdy motherboards.
Ten years ago, I was young (I was 40, ))))) and foolish.
The 440BX can easily handle a voltage of 5 V instead of 3.3 V for a minute.
And then I grew wiser. (Well, not exactly.)

Small update, I changed the 3 capacitors near the atx power connector.
Why am I proceding so slow? Well main reason is I'm bad with soldering and it's a tiring activity (more than hiking 🤣), I still struggle to properly clean the holes after desolder, I don't know if it's due to poor equipment or lack of skill, second is I don't have enough polymer capacitors and I ordered the next batch but it won't arrive before the end of the month, I still have 6 but the I'd need 9 for the cpu area.
The news is the ps2 mouse port is somewhat back to life, noisy output, if it's connected the the speaker begins to beep and doesn't work even the keyboard, but if disconnected the keyboard works fine.
I'm more confident that a full recap will solve the issue completely if I don't kill the board for good in the process!

Nemo1985 wrote on 2026-04-17, 22:04:

Why am I proceding so slow? Well main reason is I'm bad with soldering and it's a tiring activity (more than hiking 🤣), I still struggle to properly clean the holes after desolder, I don't know if it's due to poor equipment or lack of skill,

To replace the capacitors, you will need a soldering iron rated at 40+ watts (preferably 60 or 100). It should have a short, thick tip.
No “hooks” or “needles”.
If the solder does not become liquid within 3–4 seconds, the power is insufficient.
Clean out the holes – no braided wire; these are used for SMD pads.
Use either a toothpick or a needle from a disposable syringe dipped in machine oil (so it does not get stuck in the hole once it has cooled).

I have seen PS2 ports destroyed when hot unplugging / plugging keyboard or mouse.
One computer even had problems with display after this, limiting video output to 16 colors with a Banshee.
ALWAYS shut down the computer before this kind of operation. Even if it's brutal with the power supply switch..
A scandisk at startup is still better than a destroyed port, unless you enjoy serial mice 😀

shevalier wrote on 2026-04-18, 06:37:

To replace the capacitors, you will need a soldering iron rated at 40+ watts (preferably 60 or 100). It should have a short, thi […]
Show full quote

Nemo1985 wrote on 2026-04-17, 22:04:

Why am I proceding so slow? Well main reason is I'm bad with soldering and it's a tiring activity (more than hiking 🤣), I still struggle to properly clean the holes after desolder, I don't know if it's due to poor equipment or lack of skill,

To replace the capacitors, you will need a soldering iron rated at 40+ watts (preferably 60 or 100). It should have a short, thick tip.
No “hooks” or “needles”.
If the solder does not become liquid within 3–4 seconds, the power is insufficient.
Clean out the holes – no braided wire; these are used for SMD pads.
Use either a toothpick or a needle from a disposable syringe dipped in machine oil (so it does not get stuck in the hole once it has cooled).

Thank you Shevalier, I was able to solder and clear the holes much easier with your advices. The results are mixed, I begin to think there are issues that goes beyond the capacitors.
But surely we can blame them. I think raz was right as always, probably the lack of heatsink on the northbridge was the reason of it being beyond damage, just wiggle the ps2 keyboard connector it makes the keyboard 3 lights to turn on even with turned off machine.

Nemo1985 wrote on 2026-04-18, 12:09:

probably the lack of heatsink on the northbridge was the reason of it being beyond damage, just wiggle the ps2 keyboard

The keyboard controller is located on the south bridge (in VIA chipsets) or on a separate chip that handles monitoring and control of the keyboard, mouse, and floppy drive.
From Winbond or ITE.
Listen, just go ahead and measure the ground resistance and power supply for the keyboard and mouse already. 😀
For the data bus and clock.
They must be exactly the same.

nali wrote on 2026-04-18, 11:36:

I have seen PS2 ports destroyed when hot unplugging / plugging keyboard or mouse. One computer even had problems with display af […]
Show full quote

I have seen PS2 ports destroyed when hot unplugging / plugging keyboard or mouse.
One computer even had problems with display after this, limiting video output to 16 colors with a Banshee.
ALWAYS shut down the computer before this kind of operation. Even if it's brutal with the power supply switch..
A scandisk at startup is still better than a destroyed port, unless you enjoy serial mice 😀

This is a 440BX with the corresponding SIO.
They can withstand a nuclear explosion.
1. There is a mounting hole nearby. A screwdriver might have slipped and caused damage.
Most likely, the ferrite beads have a resistance other than 0.
2. The capacitor array started leaking. Back then, COG/NP0 dielectric was expensive, so they used whatever they could find, like X5R.
3. The resistor array broken out. I don’t know why—most likely a manufacturing defect.
For example, why did the resistor in the array between the GPU and memory fail on the 440MX?

I don't say it's the cause here,but I think this danger can't be ignored when we deal when other boards.
I remember in one case it happened to a friend with a Via chipset.
I don't remember what was on the other board I saw this.