So about a week ago I bought a Mac classic with the screen issue in the video below. The guy I bought it from set it up on a table outside his house to show me and it actually booted to that error screen, which it had not been doing before. (CRT isn't dim it was just in sunlight).
I recapped the analog and digital boards and performed a good cleaning as well as replacing the HOT and 2 voltage regulators (LM340 and LM317T) near the flyback.
The issue with the CRT being "wavy" and the speaker "popping" then the crt flashing is continuing to happen. Before the recap I measured 4v on the 5v line and 10.5v on the 12v line. The voltages are still at this low voltage.
I'm thinking this isn't the flyback because the CRT actually worked for a bit and there is also the persisting voltage issue.
My next move us trying the optoisolator and IRF640 MOSFET. There is a heatsinked diode D8 near the bank of capacitors at the bottom of the board that looks possibly burnt so that will be replaced as well.
Has anyone here seen anything like this before/ have any insight? I can't find this exact problem anywhere online.
View attachment IMG_1201.mp4
I recapped the analog and digital boards and performed a good cleaning as well as replacing the HOT and 2 voltage regulators (LM340 and LM317T) near the flyback.
The issue with the CRT being "wavy" and the speaker "popping" then the crt flashing is continuing to happen. Before the recap I measured 4v on the 5v line and 10.5v on the 12v line. The voltages are still at this low voltage.
I'm thinking this isn't the flyback because the CRT actually worked for a bit and there is also the persisting voltage issue.
My next move us trying the optoisolator and IRF640 MOSFET. There is a heatsinked diode D8 near the bank of capacitors at the bottom of the board that looks possibly burnt so that will be replaced as well.
Has anyone here seen anything like this before/ have any insight? I can't find this exact problem anywhere online.
View attachment IMG_1201.mp4