I have an ASUS VL/I-486SV2GX4 Rev 2.0 that does not POST at all. I get no POST codes on the diagnostic card. I initially suspected a corrupted BIOS, since the BIOS chip had its UV window exposed. I’ve ordered a programmer to verify and reflash it.

There is another issue though: regardless of the jumper settings, the CPU always receives 5V. Measuring the large tab on the transistor / voltage regulator also shows 5V on both regulators.

Looking at photos of other Rev 2.0 boards online, it seems that they usually do not have an LT1587 voltage regulator installed, although on my board there are no obvious signs that this component was added later. However, the board was clearly tampered with: some capacitors were replaced, and I also noticed that a small tantalum capacitor near the coin cell (C14) is missing.

Is anyone here more familiar with this board? Any ideas what might be going on?

I’ve read that these boards may have some form of automatic voltage selection, but I don’t want to risk damaging a 3.3V CPU by testing blindly.