Hmmm. I continue my tests without any success. I must restart from the begining. My researchs told me that this DTK PKM-0038S is in fact an OEM version of the GMB-486SG board built by various manufacturers. I found a manual who looks correct for my card, I'm going to study it right now. http://www.elhvb.com/mobokive/archive/Gemligh … sg/486sg603.pdf

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Thomas

Have you tried to put some delay or WS for the vlb and check if it help with controllers (verify if its jumpers settings for IRQ, DMA and IO don't conflict with other hardware) ? Maybe with a different BIOS or editing the existing one you will be able to enable WB, but it's only speculative and don't woth the effort for me...

Don't know if this MB is a good performer or not (you could always compare your speedsys cpu and ram score with those here to get an idea and try to tweak bios settings and jumpers settings to get matching hardware scores if not).

Personnaly, I would desolder the battery (that has already started to leak and damaging the motherboard) and clean all that (jumpers pins, rom sockets, isa & vlb slots, etc...) with white vinegar and a toothbrush (for neutralising/removing battery acid and oxidation).
Don't forget to pull out amovible parts like MB and KBRD BIOS and even the SRAMS before if you're doing it (that would be easier to remove oxidation and clean contacts and will avoid to see them die prematurely, also don't forget to clean KBRD and MB BIOS pins).
Then, when all the acid damages are gone, you can rinse the motherboard under water or use a good amount of isopropyl alcohol with the toothbrush again.
After that dry the motherboard by blowing some air on it to make sure water is completely gone from all the slots/sockets and finish with hot air like some of an hairdyer.
Finally you can check the motherboard for bad traces or contacts that could lead to instabilities and try to repair it if it is the case.
Let the motherboard rest for a day or two if it's not completely dry (if it feel humid to the touch) and put back the amovible parts and hardware.
Now you're good for using an external battery, but for testing purpose you don't really need one.

If after that and playing with bios settings and MB jumpers you can't get it working right...

About the WB L1 cache, in the Gemlight manual I just posted, it's present in the BIOS (but not in my DTK version)! If BIOS versions are comparable from one brand to another, I've got the 3.04 and it seems the last one is 3.06 but I can't find any download link.

But, why do you give me a method like my batterie have leaked? Is it something you generally do on all motherboard maybe? Because my batterie is not bad, no acid leak, BIOS saved, etc.

For now it is not that bad, but it has already started to leak and it will damage your motherboard if you let it like that (it's a matter of time).
It's a chance to do it before it get worse, all 386 and 486 motherboard (with soldered battery) that I bougth had leaked acid already eating the traces or not far from doing it... It's really a pain to repair 😵
The choice is up to you, but for me as soon as I see some soldered battery I say it goodbye 😁

Edit :

Thomas Olivaux wrote:

About the WB L1 cache, in the Gemlight manual I just posted, it's present in the BIOS (but not in my DTK version)

Or maybe because WT is already forced with jumper settings ? Elseway the bios has been limited for some obscure reasons by the manufacturer.