Car Amp trace broken, fixable?

[silentblackhat]

I have a Kenwood KAC-7201. I opened it up so i could solder some wires to the inside of the amp. i noticed that one trace was bubbled up for some reason so i blew on it to get some of the crap off of it and it blew away the trace foil. I am wondering how would be the best way of conencting that foil? or should i have an electrician do it? I have some pics of what i am talking about. the first pic is the close up, u can see on the right side of the trace that is broken, it is barely seperated. i even checked with a VOM and theres no connection.

I dont want to connect the amp and see if it works because from what i can see, this is an important part of it. it connects one of the big capacitors that are on the top of the circuit board so if my common sense serves me right, i should have this fixed(or fix it myself) b4 hookin it up

[zagisrule!]

I'd say you are go for a repair, and you can do that with some pieces of soldered copper braid (desoldering braid). A few strips of hook-up wire would also work fine. Simply scrape at the green mask to expose enough copper trace to solder the patch to.













-Matt

[silentblackhat]

alright thanks. ill try the braid tomorrow. i dont know why but when i bought new ends for my soldering iron, i saw the braid and i had a really strong feelingi would need it for something but had no idea why so i dismissed that thought but now, i know why i had that feeling

i like the amp(for what i listen to) so what i did, i jsut made a fiberglass mount for it for my trunk and then this happens:-(. the mount is specifically to fit this amp perfectly so i was seeing what my options were before i tried to repair it.

[jaycee]

Either a few good pieces of decent gague hookup wire, or (personally what i'd do) some solid copper wire from house wiring cable would patch her right up.

Seems like a nasty break though... has the amp ever been faulty or shorted at any time?

[Nigel Goodwin]

As suggested, for that to happen there has been a short somewhere, either the amp is faulty or there's been an external short (or quite possibly both!). It would be EXTREMELY rare for a PCB track that thick to fail under normal usage!.

[jackinnj]

Originally posted by Nigel Goodwin
As suggested, for that to happen there has been a short somewhere, either the amp is faulty or there's been an external short (or quite possibly both!). It would be EXTREMELY rare for a PCB track that thick to fail under normal usage!.

You can see that they were trying to maximize the surface area -- and didn't do a good job, so instead of a trace they made a fuse -- a 100 mil trace of 1 oz copper should handle 4 amps or so -- if you have the problem, other people have the problem -- copper braid is a good idea -- but you can just take a short length of coaxial cable, remove the central conductor and use the braid to make a bridge--

i am wondering what other design flaws lie under the surface. make sure that there aren't idle pieces of copper on the top surface of the board.

[silentblackhat]

there hasnt been any shorts. the reason y it looks like a nasty break is that there is a raised part of the surface under the break, the piece of copper was raised up and just flaked off. i took it to an electrician and he put a solid bridge of solder across it that small gap(didnt charge me either). do you guys agree that doin that will fix the problem? or so i need to just do solderbraid on it?

[karma]

that will work just make it the same width as the trace

and melt all of it not just the ends

[silentblackhat]

alright so i should heat up my gun and make another one? i might get some solder braid if i do that to fill in the rest.

[Stocker]

I would see if the unit will work at low power with this repair at the current stage before proceeding with more work.

If it were my own amplifier, I would call it good if it is functional like this... that braid bridge is probably at least as capable of carrying current as the original trace.