blown up Carlsbro PA monitor thing

[Left_Hand_Strat]

ok, here's the story behind this.

The guy I sometimes Tech for works at a school as a teacher, he was in a lesson when some jerkhole grabbed a bass guitar and jack to jack lead and plugged the bass straight in and played a few notes (read: BANGED) whilst the volume was on full, as a result, the whole thing has stopped working.

Basically its a monitor with a pre amp and power amp, 100W rating, all solid state. Took it apart (easy to do with plug and play wiring!) and low and behold the IC1 chip on the power amp board is totally F****d.

The chip is a TDA7293 from what I can make out left on the chip....

it seems that underneath where IC1 is, it looks a little cooked....

Now basically I am wondering what the words of wisdom are on this, I think that getting a new IC chip and replacing a few caps etc will cure the problem, only concern is that the PCB is beyond it. This would then mean me keeping the PCB and then hardwring the rest of the circuit using the PCB for guidence...

here's the pics, let me know what you think... sorry for crap quality....

Cheers.

 

[MetalManiac]

Re: blown up Carlsbro PA monitor thing

Better yet, make it a passive monitor and get an amp. Better that way anyhow.

 

[uOpt]

Re: blown up Carlsbro PA monitor thing

Got to be honest. That construction would not possibly have supported 100 watts (not hifi watts, real watts).

I would look for an alternative poweramp on a similar PCB size. Maybe, just maybe, reuse the power supply.

Are you sure the speaker's aren't popped?

 

[GoldenVulture]

Re: blown up Carlsbro PA monitor thing

Your right crappy pics. I'm not sure what you're trying to show us in some of them, they're too fuzzy.

Fixable probably, it's a one layer PCB so any damaged tracks shouldn't be hard to fix [ if there are any ] The chip should be available but you may have to go direct to a parts supplier for it, not your average electronics hobby shop. A distributor SGS components.
- http://www.datasheetcatalog.org/datasheet/SGSThomsonMicroelectronics/mXrqwxu.pdf -

I'd remove the chip and then go over all associated parts that are connected to that chip and check for faults.[ I'd probably go over all of it ] I'd also go over the power supply to make sure it hasn't been damaged by the chip frying. Depending on the results of the checks I would then decide whether it is worth pursuing on the basis of how much damage is done and how much it will cost for parts.

Edit: Nice chunk blown out of the sideof the chip.!

 

[Brow]

Re: blown up Carlsbro PA monitor thing

Better yet, make it a passive monitor and get an amp.

This would be my suggestion too. Just wire it back up with a mono jack socket and use it as a passive monitor.

 

[Left_Hand_Strat]

Re: blown up Carlsbro PA monitor thing

This would be my suggestion too. Just wire it back up with a mono jack socket and use it as a passive monitor.

i would have used my camera but I don't know where I put it...

anyway, I could do that, but I would have to ask if that is an option for the guy/school.

if that's the case I would keep all the pre amp and power amp bits for myself (some of it May be salvageable)