68kMLA Classic Interface

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Mac Classic II Analog Board testing post-recap
Posted by: 68kJules on 2022-12-02 05:50:05
Can this board be tested with the flyback transformer disconnected from the CRT? And if so, any special precautions with the HV lead from the flyback (other than not touching it of course...)

I ask because I'm about to recap it (way under spec on 5v & 12v rails) and would like to confirm that output looks better prior to putting the board back in the machine and reconnecting the anode cap since it's kind of a PITA to put on and take off.

I understand that this won't test the power supply under load.

Just want to make sure I won't hurt any components by testing this way.

Thanks!
Posted by: AwkwardPotato on 2022-12-02 10:52:18
No, these shouldn't be tested with the flyback lead disconnected, and doing so would be incredibly dangerous.
Posted by: 68kJules on 2022-12-02 14:09:44
Thanks.
After recap and replacing DP3 & DP4, I can't bring voltage up enough with PP1.
Only load on the system is the CRT, fan & logic board.
TDA4605 & CNY17 on the way.
Fingers crossed!
Posted by: xeiter on 2023-05-30 03:13:41
Thanks.
After recap and replacing DP3 & DP4, I can't bring voltage up enough with PP1.
Only load on the system is the CRT, fan & logic board.
TDA4605 & CNY17 on the way.
Fingers crossed!
How did you go with it?
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