Alpine mrv-f300 works fine for 10 min and then audio gets bad

[lukej2000]

Thanks starkeyg.

It seems to be some type of overheating problem, but I don't know if it is just that the unit is old, or because it was in a slightly damp environment for a while, or because a component has failed. Also, I tried to run it off a computer PSU for a while, which is when I first noticed this problem.

Looks like I'll have to take it apart and investigate ... local electrical shop thinks it would cost about $200, so I'm definitely going to give it a go myself rather than forking out that much!

 

[lukej2000]

I took the covers off - see images:

 

[Perry Babin]

When you disassemble it, you don't have to remove the screws from the transistors. The ones on the end of the metal risers and the two in the center of the risers are all that you need to remove for the components mounted to the heatsink. There are a few others that you need to remove in the board itself.

 

[lukej2000]

Thanks for the tips Perry.

I guess my next step is to have a look at the other side of the board and see if anything stands out to me as burnt out or damaged.

I love car audio but this is my first amp pull-down -- if anyone has any tips on general diagnosis (or even helpful links) feel free to post, thanks.

 

[Perry Babin]

Read the basic amp repair page in the sig line below (even the parts of the page that you don't feel are important). That should answer a lot of questions.