Sounds (looks) like a video memory issue.

Best way to rule things out is trying the card in another system.
Any physical damage on the card, like missing capacitors or touching/shorting video memory solder leads?
Have you tried lowering the refresh rate? Could be the RAMDAC.
Pics! :p

Run Video memory test from a floppy disk (VMTCE), that sounds just like what I was fixing on my Voodoo 3 & Banshee cards the other day. The banshee had the same behaviour where it looked fine in 16 colour mode but 256, 16-bit and 32-bit colour modes were very broken.

Thats the only AGP mobo that ive got. No damage. Ive lowered the refresh rates and nothing changed.
Here are some pics... 16 and 32 bit are bad, the lowest number of lines are in 24bit

VMTCE showed a bunch of errors... got bored and stopped it but i was a lot. So the problem is the memory on the card?

Yeah it's the RAM, my Voodoo Banshee behaved exactly the same with some damaged / non-functioning memory lines - interesting that you also see the least corruption at 24-bit, mine was the same in that aspect as well.

See if the display clears up when you squeeze the BGA chip to determine whether it's a memory pin fault or a BGA fault. One of my cards did clear up when squeezed in one corner and that means the BGA balls under the chip have come loose and the chip either needs a reflow or a reball, which is not something to do carelessly. If that doesn't make a difference then it's probably a loose leg on one of the QFP memory chips - your card uses rectangular SGRAM right?

Could you attach the VMTCE log file, I don't know how your card lays memory out but you're seeing the same glitch I was and the Banshee is pretty similar in RAM / capability to the G400.

It showed allot of errors... Ive stopped it after a few minutes.
No difference when squeezing.
I think its SGRAM. Ive uploaded a pic of the card like mine. Either way, if its not software related... its no use for me. I cant really solder anything that is that small and fine.

rakun86 wrote on 2023-12-13, 20:45:

It showed allot of errors... Ive stopped it after a few minutes.
No difference when squeezing.
I think its SGRAM. Ive uploaded a pic of the card like mine. Either way, if its not software related... its no use for me. I cant really solder anything that is that small and fine.

Probably best to get a new card and recycle / sell off the broken cards then, it takes a fair bit of soldering experience, good quality flux and probably a micrcope to fix issues with QFP SGRAM memory chips like that. I consider myself to be experienced but I still make a mess of soldering such fine pitch chip legs.

In the bin with the faulty G450 it is then... and my trusty ati 128 pro back in the AGP.
Thanks for the help.