I have the same board. The jumpers that set the cpu voltage are indeed absent, and it is hard-wired to 5v. But if your cpu needs 5v as it says, there shouldn't be a problem. Normally I could upload the manual for you, but I have it in my Lenovo laptop, which died two days ago, and I haven't recovered my data from it's hd yet. But maybe this might help you : http://stason.org/TULARC/pc/motherboards/S/SO … SY-25M-N-P.html

I've had 3 different speeds reported from it so far, 16, 20 and 32Mhz! I think somethings not right somewhere!

*Update*... Got the manual to confirm the jumper settings and they seem right... cpu/board issue? Can't think why it still shows up as an 80386DX 🙁

Hi, I've the same mainboard SY-25M/N/P I'm trying to set up a AMD DX2/66 CPU but got no luck so far. Yes, the voltage is however at 5V. This is no prob for Overdrive or DX2/66. My board shows UNKNOWN CPU 50 MHz. If I reset it, the ist is only 32 MHz. It makes me crazy, really. I've got the correct jumper settings (thanks for uploading the manual), but no way. And another problem: the board starts only one or two times, and then I've got to disconnect all card and cables and reconnect them to make this thing run again. What's wrong with it? I tried another CPU's DX2 66 (i), dx, sx... But your issue: Remeber, there is a turbo switch on this board. It doesn't help me, but probably you.

These seem to be permanently set for 5v CPUs... I'm beginning to think the Overdrive 66mhz or DX2/66 are the only ones that will work in it!

Ok. Now the board ist running and showing DX2/66 at the diagnostics screen 😁
I did following:at 1st (I think this was the problem) I removed the complete cachefield and replaced them with 9 equal rams (the rams first installed had an ending xxxxxxx-15 it means, they are 15 ms fast. In the manual however are xxxxxx-20 rams installed) make sure, to set the pins correct, like in the manual at page 15 (32k*8-20 rams) all banks filled.
at 2nd: Set up the pins like shown at page 8. Make sure to set up ALL of the pins you can see at the manual page, not only 34,29,30,31.

This is it. It worked for me fine. I think, the cache was the main problem. You need nine 32k*8 at 20 ms. not 32k*8 at 15 ms. Sounds curiosly, but the bugs it produced were curious too 😉

edit: i looked at your pictures. Ican see, which jumpers ar wrong. Now I've got to go, but I'll tell you, what's wrong, when I'm online again

edit: Ok here I am.
remove J23
remove J22
J21 1-2
J19 4-5
J18 2-3
J15 3-4
J11 3-4
J14 3-4
note you have set at J11 or J14 TWO bridges. remove the wrong one.
I hope this will work for you.