(under development, will update as I go)
Seller Note “Dead”
Summary
- I bought two of these very cheap (£8 each) and didn’t expect much, both missing fans. When I received them, I measured them both to have only 1.2Ω on their VMem rails and I jumped to the conclusion they both probably were dead and have faulty cores. So I put them to one side, almost directly in the scrap area. However… I thought I should at least give them a proper look. Injecting 1v into the VMem rails revealed that each in fact has 1 shorted VRAM bank, which can be fixable! So, game on after all! 🙂
- Resistances
- TODO
These cards have VRAM chips on both sides of the card, making a very useful 6Gb of VRAM.
One has a damaged component on the back:
I need to try removing the shorted VRAM chip from each card and see if the VMem rail resistance rises.
Card A
Starting with the one with no ripped component. Lets test by injecting <1v into the VMem rail and see if anything heats up.. and yes, one of the chips does:
Quick update, removed the seemingly short VRAM chip.
But the short remains, possibly I accidentally messed up some nearby components.
No nearby components seem impacted and injection <1v again reveals the adjacent VRAM chip on the same side is also shorted.
TODO Add thermal images.
Removing the 2nd shorted chip restores the VRAM chip to a much more healthy 60Ω. Whilst this seems like progress, it could be a bad sign that 2 chips have shorted.. The only way I know how to find out is to replace the 2 chips with new VRAMs that I have in stock – Hynix H5GQ2H24AFR-R2C
After removing the other VRAM chip with a preheater and 450 deg hot air, I cleaned up the old solder by first applying a little leaded solder and then wicking the pads.
Then I applied a light coating of flux gel.
Then, before using the preheater and hot air to resolder the 2 new chips, I very slightly misaligned the chips so that when the solder balls melt, the chips can be seen to visibly shift into place so I know when to remove the heat.
After the board cooled down, I remeasured the Vmem resistance and it is still close to 60Ω (say 50Ω and climbing due to the board still being warm). Time for a test, and …. nice! Great to see the card working against the odds, now I need to find a decent cooler! 🙂
TODO picture of the card working and more stress testing (limited without a fan on the remains of the cooler it came with.
Card B
Lets hope we get lucky with this one too