PS1/2 PS1 Fat after desoldering modchip and reinstalling one newer, laser doesn't work anymore

[elcarajos666]

Today I just picked up psones for checking, I desoldered one modchip that had one of the psones, i desoldered the one that came on my PS1 Fat which never worked since I bought it, the guy who soldered the modchip on the PS1 fat wasn't the correct one, I soldered correctly for the 750X one, after finishing, my laser stopped working, I desoldered the modchip, and the issue was still there, discs are still rotating and laser is still working, but seems data isn't beginning reconigzed by the ps1, no backups, no music, no original discs. Do anyone has a clue? or did I screw my PS1 fat?

 

[FAST6191]

It has been a while since I did anything with the PS1 but the usual suspects in such scenarios are you made a cold joint, you cooked a part (PS1 era stuff was not necessarily as tolerant of heat at things are today) and or you broke a trace/pad somewhere in it.

I don't think there is anything weird done for the PS1 like the chip takes over drive functions and you need to disable the original so I am back to the stuff above. If simply checking the joints and reflowing them does not work then if you want to install the chip again and see if it comes back it will give an answer there.