Macintosh Classic chime but no video

[bengi3]

So I am trying to liberate this Mac Classic. Analog is good (fine with another good logic), logic recapped: I got the chime but then dark screen and it reboots in a loop: chime --> dark screen --> reboot --> chime --> dark screen.

What to check then?

 

[Bolle]

Check the voltages. My guess would be bad analog board.

Different logicboards might slightly differ in voltage tolerance - this might be the reason that one board works but not the other.

I have yet to see a Classic that does not have bad caps on the analogboard.

 

[bengi3]

thank you, your thought confirmed my intuition. will try this logic boand on a fully recapped analog from another Mac that I liberated a couple of months ago, and let you know.

 

[bengi3]

No way: I tested this logic with another good and recently recapped analog:

https://youtu.be/uL20no3l-b8