exactly. I found it very strange, I even thought it was something related to the reader.
I still don't know how to attach images showing the weld.
Should I use the ISP connector to program?

Hello colleagues,
I'm having problems unlocking a PS1 model 5001.
Welding was carried out according to the manual on the PU-18 board model.
When starting the backup CD, it does not show the PS1 black screen logo, it is completely dark and only the sound appears as if it were starting up.
I used ...