Amp drops out after a couple of minutes. (Sony DA5300ES)

[ynneb]

Recently I purchase a second hand 7.1 Surround Amp (Sony DA5300ES)
The guy who sold it to me paid nearly 3k for it, but sold it to me for 90 bucks, saying that it would drop out from time to time.
It has been working fine for me the last 2 months, but the other day it did drop out during a CD session
It dropped out with a loud pop in the speakers and then no sound. The front panel is still displaying fine.

I decided to open it up and do a blown capacitor hunt. The build of this thing is utterly amazing with stack of circuit boards and load of connector ribbons etc. Not to mention the over the top ammount of screws.

I was quite scared to pull it totally apart due to not been able to put it together again.

Anyhow I guess I'm asking if anyone has any suggestions of where I should be concentrating my inspection. So far it all looks OK. No brown bits anywhere. I'd much prefer brown bits. Oh and no obvious smell either

Going off the description of playing for a while then suddenly stopping with a pop, what does it sound like to you? Oh and if I turn it off and leave it for a while, it comes on again for a couple of minutes before doing the same thing?

Any suggestions?

 

[KeepItSimpleStupid]

I do need to ask if protect is displaying: See: **broken link removed**

The service manual is located here http://elektrotanya.com/sony_str-da5300es_ver1.4.pdf/download.html free.

All channels out?

 

[JimB]

Going off the description of playing for a while then suddenly stopping with a pop, what does it sound like to you? Oh and if I turn it off and leave it for a while, it comes on again for a couple of minutes before doing the same thing?
Any suggestions?

If I had a piece of equipment that was doing things like that, I would suspect a bad solder joint.
The joint may not even look bad to the untrained eye, but it is.

Apart from looking closely at each solder joint, an easy way to start fault finding is to gently poke at each joint with an insulating rod, something made of plastic or wood.

JimB

 

[ynneb]

Hi KISS, thanks for your link to the service manual. I will take a look through it.
There are no error messages. I'm not sure about all channels stopping, but definitely A + B left and right.

Hi Jimb so no lead pencil for the prodding exercise? Nice idea I'll give that a try too.

Benny

 

[KeepItSimpleStupid]

I didn't look at the manual at all. DC on the speaker terminals is the cause for protect to go on. You can sometimes chase the audio signal externally or at least determine if it's pre/or power amp problem.

Freeze spray is useful, but you still need some sort of target. I have two OEM car amps that have problems, but I can't do anything until i make a harness. Differential inputs and outputs wit an equalization circuit. Just tough getting access to the 4 speakers, and 4 differential inputs.

Amp seems straightforward. The one with distorted signals might be the easiest to fix. The one that dies at about 65 degrees F is going to be harder.

 

[4pyros]

If it has that many interconnect cables inside, It is likely a bad connection at one of the connectors.
The power connectors will oxidize first.
Re-seat all the connectors.