Hi, I have one of these boards, it's broken beyond repair and I use it for spare parts so I can try to desolder those 3 caps and read the values for you.

I'll try to do it tonight if I find the board in my stash.

These are the values:

• C4: 100nF
• C6: 47pF
• C8: 47pF

Hi TheMobRules, many many thanks ! Saving good motherboard which has potential, ... and will have many tests done soon 😀

Actually I have a question about the voltage of these capacitors. From what I see I have available :
- 25V C0805, 100nF
- 50V C0805, 47pF

Can you advice if these will be suitable as a replacement ?

emil.p wrote on 2025-07-04, 10:16:

Hi TheMobRules, many many thanks ! Saving good motherboard which has potential, ... and will have many tests done soon :-) […]
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Hi TheMobRules, many many thanks ! Saving good motherboard which has potential, ... and will have many tests done soon 😀

Actually I have a question about the voltage of these capacitors. From what I see I have available :
- 25V C0805, 100nF
- 50V C0805, 47pF

Can you advice if these will be suitable as a replacement ?

Yeah, these values are suitable.

thank you kotel ! really appreciate it ! getting a bit of experience with you in such topics is cool !

I bet they were like 50v or 25v, but since these board (almost) never have any voltage higher than 12v, it's safe to use anything above said voltage.
General rule of thumb is, you can pretty much always go one step higher in voltage rating for caps, one step lower, not so much (unless the caps used were 10v on 5v and you want to replace said caps with 6.3v).

That was what I wasn't sure about ! thanks for explaining it.

The worst is that my multimeter 1) KAIWEETS HT118A and 2) AP-990C SMD Meter shows for smaller capacitors (new caps I mean) than 100nF completely different values but when I test new capacitors with 100nF then they always display exactly same value !
Seems one of these two devices can't measure properly capacitors their small values. Not sure only which one 😁 and I can't solder it yet except the 100nF

Eg. the device 2) shows always larger value: ~0.020nF more than device 1) - except 100nF like I mentioned above

I just recalled (ADD here, so don't be surprised 😁) that I have another LCR meter 😁 3) Hantek1833C (bought long time ago and completely forgot about it) and ...
- 100nF shows as a 95nF and other two (more or less)
- other 2 caps values are same like device 2) AP-990C ...

So, I think I can assume device 1) has some issues with small range caps. But now I know 😀

Does anyone know if this board could use 486 DX4 100Mhz 3.3V ?
I don't see any direct info in the docs, only DX2 and Cx486 DX2 and I don't see any jumpers for voltage change, but still I'm not sure what is the voltage for the CPU in this motherboard

This is a 5V only board, so to use a DX4 you would need either an Overdrive or an interposer.