Sony STR1050 - not working

[Teessider66]

Good evening.

I have a Sony STR-DN1050 which suddenly went pop. When I press the on button, or use the remote the front display seems OK, Turning speaker volume shows the display increasing, I can select input, but it does not output any signals, audio or video.


When the stand by button is pressed I hear a relay click, which I assume is the standby relay. The primary side of the main transformer is 240V AC. When the stand by button is pressed there are voltages on the secondary coil ranging from 11.1 to 85 VAC. The main transformer does not seem to power up to the usual hum.

Any help would be appreciated before I spend £60 just to get Richer Sounds to look at it

 

[kct]

You might need the Service Manual. If you don't have it, here is a link.

SONY STR-DN1050 Service Manual download, schematics, eeprom, repair info for electronics experts

I suspect the DCDC board could have a problem.

 

[Teessider66]

Thanks. I can't see any damage to the capacitors and the fuses are intact. I'll check some voltages out the board later

 

[synonymous]

My old Sony many years ago activated it's protection circuit when the output device failed. Soon after that repair, I had to take it back when the other channel failed. If it's an output device, replace both.

 

[Teessider66]

What do you mean by output device? The pop came from a rear speaker, I think.

 

[nfsgame]

What do you mean by output device?

The creepy little things with three legs and a big fat body mounted on the headsink(s)...