Astec ASP34-4 vs. ASP34-2

[pixelpusher]

Hi folks,

greetings from Germany in the fading hours of 2019.

I was looking at two broken Astec psus - both delivering no output voltage (looks like the SB340 diode's are bad) with the intend to resurrect at least one of them.

As the ASP34-4 looks less beaten (the transformer of the 34-2 seems to have gotten very hot, one trace on the pcb was rebuild with a wire, ...) and comparing the schematics of both psus briefly: Is there are reason to not use the 34-4 in the ST? Both should have the same output capabilities according to the specs.

P.S.: Any "pro" tip what besides the SB340 diodes might have gone belly up and should be checked before powering the unit up?

[exxos]

There are a lot of ASP34 revisions https://www.exxosforum.co.uk/atari/last/ ... .htm#ASP34

You may have to remove the diodes from the PCB to test them properly.

[pixelpusher]

I could already check the faulty psus against a working version of a ASP34-2 (and therefore conclude that - at least - the diodes are bad).

However, my question wasn't about the revisions of the ASP34-2 (it is a rev6 according to the pictures in your thread), but comparing the 34-2 against the ASP34-4 originally used as Megafile psu (and if there's a good reason to not use the 34-4 in the ST).

[exxos]

They are all basically the same PSU. Mostly the metal bases can be different.