The case of the possessed Sony TA-N77ES

[Nick89rs]

That's the thing. It's intermittent and even just the weight of the RCA lead can 'fix' it. I bet the tech tested it and it worked perfectly.

Funny, I put off doing my own TAN 77es for about a year or two because I "knew" it was the speaker or input relay and I could be bothered pulling the unit down. I also "knew" it couldn't be the RCA input jacks because I tried both fixed and variable and both lefts behaved the same. I just got out another TAN-77es and put the unit on the back burner until I had space on the bench for the monster.

But I was wrong. Two left centre pin RCA bad solder joints. Sony didn't use anywhere near enough solder (that's original factory in the above pic) on the lefts for some reason and dis-similar metal corrosion on the pins did the rest. In the end, all it took was 10 minutes to fix as the input board is easy to remove and work on without dismantling anything.

Here's the input board. For sure not the healthiest looking.

 

[restorer-john]

For sure not the healthiest looking.

Just remove all that solder, clean up the pads and area and resolder. If you didn't make that mess, someone has been there before.

 

[Nick89rs]

Just remove all that solder, clean up the pads and area and resolder. If you didn't make that mess, someone has been there before.

no, first time im seeing it. this is my first foray into any amp.

 

[MFRD]

Looks like you added a lot of solder while reflowing that board. Might have created a solder bridge somewhere, and the resulting short is causing the protection fault you're now seeing.

 

[Nick89rs]

Looks like you added a lot of solder while reflowing that board. Might have created a solder bridge somewhere, and the resulting short is causing the protection fault you're now seeing.

It's possible. Right now I'm using a magnifying glass out of a 1920s detective novel to try and see what I was doing. I've got quite a few new tools on the way as I was not as prepared for this as I assumed. I've got a magnifying light, hakko solder sucker, and new much smaller tips for my iron coming as well as a scope. Waiting for everything to get here before I put tools on the board again.

 

[dr*audio]

That's the thing. It's intermittent and even just the weight of the RCA lead can 'fix' it. I bet the tech tested it and it worked perfectly.

Funny, I put off doing my own TAN 77es for about a year or two because I "knew" it was the speaker or input relay and I could be bothered pulling the unit down. I also "knew" it couldn't be the RCA input jacks because I tried both fixed and variable and both lefts behaved the same. I just got out another TAN-77es and put the unit on the back burner until I had space on the bench for the monster.

But I was wrong. Two left centre pin RCA bad solder joints. Sony didn't use anywhere near enough solder (that's original factory in the above pic) on the lefts for some reason and dis-similar metal corrosion on the pins did the rest. In the end, all it took was 10 minutes to fix as the input board is easy to remove and work on without dismantling anything.

Click and Clack would have played the "Ta-Dah!" sound!

 

[Nick89rs]

Just remove all that solder, clean up the pads and area and resolder. If you didn't make that mess, someone has been there before.

Had some time today and got that mess all cleaned up. Pretty happy with how it came out. Scope and new much smaller iron should be here this week for more serious investigation