EDID/DisplayID Writer

[bderleta]

Thank you! Your tool allowed me to fix my old Dell 1704FPV with corrupted DVI EDID (apparently wrong checksum, I know no reason). Of course, the EEPROM was write-protected, but having it dumped made things a lot easier. I crafted an EEPROM writer using NodeMCU and modified the checksum to calculated one using a simple pieces of LUA software (I can provide more details if anyone interested).

https://photos.app.goo.gl/W5GERTXfE64rXBP97

One note regarding the guide linked: it seems (and probably is) dangerous to desolder WP pin of EEPROM as a first approach. I would recommend first measure Vcc-WP resistance - that's because some vendors don't tie WP to Vcc directly, but via some pull-up resistance (to enable, for example, pulldown controlled via some GPIO). In that case it's perfectly sufficient to temporarily bridge WP to Vdd (GND), without any serious soldering/cutting.

I used W10 x64, DVI-HDMI cable and MSI RX5700XT (I have two of these in MGPU conf.) for reading, unfortunately, didn't test the writing. Also perfectly read EDID from Dell U2718Q and U2720Q.