I modded this system about 2 weeks ago and it worked perfectly playing backups, etc. Now the customer contacts me saying it is acting like there is no mod chip anymore (can't enter modbo settings by holding Cir, Tri, MOdbo not displayed below Playstation logo, etc). I tested it myself and sure enough it is like there is no chip in it so only original games play fine.
I opened it up and the wiring is still perfect, nothing came loose. Rechecked continuity and all points are good. Reflowed all points just to be certain and rechecked continuity. System still acts like no chip. So I thought it was a bad chip and replaced it, and again rechecked all my points with a multimeter but I still have the issue of it acting like no chip is installed.
Anyone have any ideas what I should check next as it can't be the chips (second chip is a known working one out of another machine), can't be the solder joints as they pass 10X magnifying glass and a multimeter, and the points I am soldering to are correct as they worked before, and on other systems.
THis system will be the death of me