Eimer wrote on 2024-11-04, 20:01:

I went with the additional jumoper configuration guide here...
https://theretroweb.com/motherboard/manual/cp … 56022401852.pdf

I guess the first configuration on the sheet should be correct, but the manual states something different for P24D and P24CT..

Exactly. The DX4 with write-back cache is exactly what they mean by "DX4 &EW". It's also identical to the Am5x86 jumpering (except for JP20 1-2 is 2x for the DX4 and 4x for the 5x86), which confirms the settings to be appropriate, as this is the only difference to be expected. I get suspicious though, as the table does not clearly specify how to jumper WB mode. "JP21 2-3 short for WT" is not followed by "(all open for WB)", although this is clearly a jumper connected to the WB/WT pin (which is the 2x/3x selector on the AM486 NV8T). Furthermore, it is completely left as an exercise to the reader what to do with JP16 for WB mode: Should you just skip 5-6? Should you have it "all open"?

As the WB configuration is clearly not described in the settings guide, I'm afraid that possibly the WB mode does not work correctly and got redacted from the jumpering guide, so you are on your own regarding that.

The differing configuration for the P24T (PODP) is due to the 237-pin package instead of the standard 168-pin package. Ignore the PODP jumpering.

so I'm not exactly further.
should I just follow the first configuration in the sheet and check speedsys?

Also I set JP32 to 1-2 to have 3.45V.
But I see no 5V jumper, or is it like.. JP32/33 no jumpers is 5V ?

Eimer wrote on 2024-11-04, 20:29:

so I'm not exactly further.
should I just follow the first configuration in the sheet and check speedsys?

The first configuration will work. It will support your WB capable processor perfectly, but it will run that processor in write-through mode. If you want to enable L1 write-back, you need to start experimenting.

ok tried it but theres absolutely no reaction from the board.
POST card shows nothing on the digits, only control leds lighting up.

CPU and RAM were pulled from a working system, put them back in and they still work.
ATX2AT Smart Converter was used for power supply. Which works flawlessly with a different board.

Eimer wrote on 2024-11-05, 21:05:

ok tried it but theres absolutely no reaction from the board.
POST card shows nothing on the digits, only control leds lighting up.

This means the CPU does not execute BIOS code at all. The most common reason for that symptom I had in my lifetime PC experience was that the CPU was not fitted deep enough into the CPU socket. Bad RAM will not prevent the first codes to appear on a POST card. The most likely, if you are confident the CPU is properly fitted into the socket, is a defective mainboard, e.g. because some trace is broken.

Does the RESET LED on the POST card stop lighting shortly after turning on the system? If it does not light up at all, connect a reset button to the board and push it. The LED should light at least as long as the button is pushed. If the power-on reset logic on the board is broken, it will spring to live after pushing the reset button. If the RESET LED is permanently lit on the POST card, the board will not allow the CPU to start executing code. The reset circuit on the board is likely the culprit in that case.

reset stays lit. also chipset ICs don't get warm at all and stay cold.