On Tue, 27 Sep 2016 19:00:14 -0300, you wrote:
As I mentioned above, I decided to take my chances with the ESJA53-12I have not quite decided what to make of this but I have some ideas.
If the diodes were the problem, then I would have expected changing
them to have completely fixed it instead of making it a little better.
What I might try is looking for some other part which is getting hot
causing enough leakage to pull the high voltage supply voltages down.
If you do not have an infrared thermometer to scan with, a cotton swab
dipping in rubbing alcohol could be used to cool suspected parts after
the HV supply starts to collapse to see if it has any effect. Q1486
and Q1484 would be especially good targets for this test.
Freeze spray is what would normally be used for this but I would be a
little leery about using it around high voltages where condensation
might cause problems.