Anyone here repair car amps? :)

[coffee]

So, I was given a fosgate Prime R500-1 amp. Kinda a nice one. I have trouble shot the issue and the output mosfets are blown on one channel KTA1962A . I found them on ebay but will probably take a month to arrive.

Wondering who here tinkers in amp repair and where do you get your parts. This mosfet is basically not available in the US I guess. Mouser, Fairchild do not supply it.

Would be also nice since this is basically not a component level forum that someone might recommend one for this type of work. I know bad caps and will post there also.

Thanks for the off topic replies anyone,

 

[Moltuae]

I used to repair car amps, and pretty much any electronic items down to component level. My background and training is mainly electronics design and repair in fact. Working on/with computers began as a sideline 20+ years ago.

That's not actually a MOSFET, it's a PNP Bipolar. Should be fairly simple to source an equivalent. How have you tested them?

 

[Moltuae]

Fairchild and ST seem to have produced equivalents, the FJA4213 and 2STA1962 respectively.

http://www.digikey.com/product-detail/en/fairchild-semiconductor/FJA4213OTU/FJA4213OTU-ND/1056906

http://www.digikey.com/product-detail/en/stmicroelectronics/2STA1962/1026-2STA1962-CHP/2521314

Both slightly different (generally improved) specs form the original BJT that you have but they should work. Once you've confirmed they work though, I would recommend replacing all of the power bipolars on each channel with the same transistor to ensure the hfe (ie gain) is the same on each channel.

Be very careful if the replacements you ordered are from China. I've had transistors from Chinese suppliers that are not what they purport to be. They look like the genuine article and are even stamped with the correct part number, but they can be a completely different transistor part/type, which could potentially cause damage to other parts of the circuit if used.

 

[Altster]

So, I was given a fosgate Prime R500-1 amp. Kinda a nice one. I have trouble shot the issue and the output mosfets are blown on one channel KTA1962A . I found them on ebay but will probably take a month to arrive.

Wondering who here tinkers in amp repair and where do you get your parts. This mosfet is basically not available in the US I guess. Mouser, Fairchild do not supply it.

Would be also nice since this is basically not a component level forum that someone might recommend one for this type of work. I know bad caps and will post there also.

Thanks for the off topic replies anyone,

You might wish to contact these folks as I know they do good work and will go out of their way to lend a hand - even go as far as send you unit in for factory service (if needed.)

https://www.facebook.com/YongsAudioConnection/

Plus they are neighbors of ours (at the computer shop / warehouse.) They used to be in the same strip mall as us and we got to know them quite well. Good people.

 

[coffee]

I used to repair car amps, and pretty much any electronic items down to component level. My background and training is mainly electronics design and repair in fact. Working on/with computers began as a sideline 20+ years ago.

That's not actually a MOSFET, it's a PNP Bipolar. Should be fairly simple to source an equivalent. How have you tested them?

Yep. I just figured it out and found the equivalant from fairchild. In fact, I just spent some more time diagnosing it (them) as they are PNP not NPN. So, I was a bit mixed up. Thats ok - At least I figured it out.

The amp uses the 1962 and its compliment the 5242 on the other. This now makes sense to me.

I am doing this work because I have some spare time and just basically compelled to do it I havent done board level like this for years and even then rarely - no expert. But its all coming back to me now.

Found the 2STA1962 and was about to order up some and then sat down and retested the chips. Because I was a bit mixed up, I did not test them right. So, I rechecked them and sure enough its fine. No need to do that.

I did order in a P/S to push this amp on the bench. Needed one anyways for the work I am getting into. Got this one here:

https://www.amazon.com/gp/product/B00SWK6M0M/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Should be good enough for my purposes.

Thanks for replying!

 

[coffee]

You might wish to contact these folks as I know they do good work and will go out of their way to lend a hand - even go as far as send you unit in for factory service (if needed.)

https://www.facebook.com/YongsAudioConnection/

Plus they are neighbors of ours (at the computer shop / warehouse.) They used to be in the same strip mall as us and we got to know them quite well. Good people.

Thank you very much for the reply.

Well, This is one of those things that I want to do myself. I have a power supply ordered up - Needed one anyways for the shop

 

[Moltuae]

The amp uses the 1962 and its compliment the 5242 on the other. This now makes sense to me.

Yep. Most likely a Push-Pull output.