Sony CR44 power supply repair... or not?

[clh333]

Been reading  http://www.ccadams.org/se/classicmac2.pdf and also Pina's books for info on repairing Mac SE power supplies.  I have a Sony CR44 that tests the -12VDC lead as -8.5, +5VDC as 5.3 (both lines) and +12VDC as 13.5 and 14.2 respectively.  I have already recapped the PSU and am reasonably confident the error is not the result of that work.  However, that's as far as I went and now I suspect that the problem lies elsewhere.

I have three choices, it seems: try further repairs on this unit; buy a (used) replacement or find a new supply to use instead.  Each of these presents its own challenges.  Pina is certain that IC 151, a Sony IK1H4, is at fault.  I can't find that part anywhere and I have no cross-reference or data-sheet for the part.  A used power supply may well have, or develop, the same problems this one has.  A new power supply will probably need to be adapted for use in the Mac, and apparently not many supply two independent +12VDC supplies.

I'd be happy to hear suggestions as to how to proceed.  Thanks for your replies.

-CH-

 

[Johnnya101]

If needed, I have a PSU that I got in my haul from an SE with no cover on it, so assuming its a parts PSU. Could swap out some stuff from that.

 

[clh333]

Thank you for the offer.  Let's see if anyone else has any ideas.  I'd really love to find that Sony chip or a replacement.  Better yet I'd love to find out why the voltages are so far off.

Thanks for your reply,

-CH-

 

[trag]

There's a thread around here somewhere about replacing the guts of the SE or SE/30 PS with the guts of a mini-ITX or 1U power supply.   If you can't nail down your component failure you might look at that solution.

 

[SE30_Neal]

I saw that it wasn’t long ago, within 4-8 weeks

 

[Jinnai]

I want to know if you find a solution. Your voltages aren't that far off: mine has between 1 and 2 volts on both 12v and 5v. I also recapped, but it didn't fix it.

 

[JackRubin]

@clh333 - did you ever find a source for the IK1H4?