PSU help!!!! (Transistor identification)

[T-R-A]

...Maybe one component failed and then there was just a cascade of failures from that...

Not likely. A failed component might take out a couple more with it , tops...but a power surge (as Chuck (G) mentioned) would wreck havoc and take out a large number of them (such as you have)...

 

[Jonno]

Hi all, a friend and I have been working or resurrecting a 5160 PSU (220v). It's been a mission!

We have replaces a number of components that were either obviously dead or corroded and crumbling.
Unfortunately, still no luck getting it to work.

I was wondering if anyone recognises this part (see attached), and what would be a modern main switching transistors replacement.
The two on the board are dead, so I got some some J13007 transistors as we I thought they would work well...now it looks like these replacement transistors are not compatible as they do not switch on, even with the drive on the base looking ok.

Anyway, if anyone can help with identifying a modern replacement would be most appreciated.

Thanks

View attachment 1268107

For what its worth, and in case anyone else comes this way, I'm currently diagnosing what appears (from the photo at least) to be the exact same model PSU from a 5160. In place of the pictured component there are indeed MJE13007 transistors in place. (Q1, Q2)

If/when it's resurrected I'll report back with what had failed.

I'm using the opportunity to do a full electrolytics recap and will also post the cap list. The caps all look and test ok and there's no observable leakage but hey after close to 40yrs they're way outside their original design duty cycle.

 

[bitwhacker]

Good job. Here's a little tip for fixing switching PSUs (also CRT monitors, amplifiers, etc.): put a light bulb (40W works great) in series with the mains power before powering the device up. This limits the current and prevents components from blowing up if there is a problem. Plus, if the bulb glows brightly when powering up the circuit, that tells you immediately that there's a short somewhere.