I have a brand new batch of 39SF040 chips from Mouser. Most of the chips (7 out of 10) fail when writing using my GQ-4x4. They all fail at the same address every time: Write failed, Address=0x01546D, Buffer=0x80 Device=0xC0.
I'm experienced burning flash chips and I've tried all of the usual troubleshooting methods/handling precautions I know of. I'm hoping I missed something and someone can help me out.
It seems unlikely that 7/10 chips would be bad straight from the manufacturer but that's a possibility. I'm wondering if there's a problem with my GQ-4x4, though it does seem to be writing 27C040s just fine, plus I burned an old 39SF040 from an different batch about 10 times over the past two days without issue.
It seems those chips may have programming compatibility issue.
Try to slow down the speed.
If it still does not work, it is best to ask support@mcumall.com for ending a testing chip to MCUmall to fin out the problem and fix it in software if possible.
There does indeed appear to be some kind of incompatibility. I was able to complete the writing process at -2 speed but verify fails and there are errors when doing a parity check on the data. I also receive occasional errors when trying to erase the chip, which I hadn't seen before, but it doesn't happen every time I try to erase.
I will try contacting support and hope this chip can work with the GQ-4x4. Thanks for your help.