It is a Mask ROM, so you cannot update it or anything.

Though... you probably can replace it with a properly programmed eprom .?

Good to know - thanks!
Then the numbers on the circuit are specifically made for the manufacturer, I suppose. When reading "HMxyz..." I thought of some Hitachi chip. But something would to be found on the net in this case.

The card has started working again out of the blue. I will use it as my test-card in the weeks to come and report when it´s failing again.

Try dumping the video BIOS while the card is in the PC and see if the checksum is correct.

I'm sure you've already tried this, but quite often I can fix intermittent issues like this by thoroughly cleaning the gold fingers using isopropyl alcohol.

kdr wrote on 2021-04-12, 23:23:

Try dumping the video BIOS while the card is in the PC and see if the checksum is correct.

I'm sure you've already tried this, but quite often I can fix intermittent issues like this by thoroughly cleaning the gold fingers using isopropyl alcohol.

Or a pencil eraser. Fixed dozens of cards this way. 😀

Ozzuneoj wrote on 2021-04-13, 07:08:

Or a pencil eraser. Fixed dozens of cards this way. 😀

Just don't erase the PCB traces or gold-plated contacts! 😀

I once made the mistake of trying to "fix" some corroded gold card edge contacts using sandpaper. Oops. It did a great job at removing the corrosion... along with all the gold underneath!

You can get the bios here ... http://www.vgamuseum.info/index.php/cards/ite … dent-tgui9440-1

Then you need an eprom programmer and a 27c256 chip or equivalent.