Did you just remove the battery, or did you connect another battery instead? Some motherboards won't boot without a battery.

Try putting the VGA card in different slots. Too bad you don't have a spare VGA card to test. I can say the Trident cards have good compatibility. Also check for any broken traces on the back side.

stamasd wrote:

Did you just remove the battery, or did you connect another battery instead? Some motherboards won't boot without a battery.

It's good to know as I have a few boards that won't boot and don't have battery installed.

That battery eerily reminds me of a can of Surströmming. Thank goodness you've already removed it, you don't want to smell it when it starts to leak... 🤣

alvaro84 wrote:

That battery eerily reminds me of a can of Surströmming. Thank goodness you've already removed it, you don't want to smell it when it starts to leak... 🤣

better than a bag of hákarl.

stamasd wrote:

Did you just remove the battery, or did you connect another battery instead? Some motherboards won't boot without a battery.

Even systems as new as a 386? Thought that was more an Apple thing..

I discovered a missing pin 4 of an SO-14 IC (U8, bottom left). A DM7406 hex-inverter with open-collector high-voltage outputs; an odd-ball. I've ordered another.

The broken leg was an input to one of the inverters. That inverter is in series with another, going off somewhere on the board. Acting as a buffer or delay line.
Removed it to see if that pin was connected, breaking the chip. At least with the new chip i could see if it needed that missing leg, or if it was a factory bodge.

--

I now have a 286 board, and some interesting results.

With the 286 board, the system will sometimes boot, and sometimes give the same AMI video memory error beep.
It will always give the beep on first boot after you've left it a dozen or so seconds off. Reset doesn't help. The next cold boot within a few seconds will have it working. This makes me think maybe the video card has an issue, and the 386 board is fine after all.

I'll know when I finally get more VGA cards to test.

The one system that this suspect VGA card worked perfectly in, was Sergey's Micro 8088 XT system, in 8-bit mode.

Putting the card in an 8-bit slot in 8-bit mode in the 286 board produces the same results as the other slots in 16-bit mode.

I replaced the tantalum caps (3 x 10uF, 2 x 2.2uF) on the VGA card, to no effect.

The VGA card is a 9016X2 / 4 LT2 REV.B. Here's a pic:

I've tried all combinations of VRAM, with new chips and the originals.
It never works with only 256KB, either producing same beep from mobo, or corrupting on first screen.

The two jumpers at the top right don't help, and I can't figure out what they do.
They make the screen corrupt differently when there's only 256KB RAM.

Here's the 286 board the VGA card only works sometimes in: http://arvutimuuseum.ee/th99/m/A-B/30650.htm

nztdm wrote:

stamasd wrote:

Did you just remove the battery, or did you connect another battery instead? Some motherboards won't boot without a battery.

Even systems as new as a 386? Thought that was more an Apple thing..

Even systems as new as socket7. I once "repaired" a non-POSTing Pentium system by replacing the CMOS battery.