Newb in need of help.

[bmf85]

Hey all!

As stated I'm a newb, to the forum at least. And, just recently diving back into the realm of car stereos after a fairly lengthy hiatus.

Anyway, I recently acquired an old school AudioPipe GD6001 for stupid cheap. When I got it, it was covered in dust and cob webs so I didn't even attempt to power it up. I took it home, blew it out with air and tried to power it up when I started to smell the lovely Fet burn.

Upon opening it up I see 1 very burnt IRFP064 and corresponding resistor on the board. After further looking it appears what I believe to be the 4 drivers for those Fets have been replaced also and the ones currently installed are FMG32R.

The smaller Fets seem to be in working order but are a mix of IRF9640 and IRF640 with some having been clearly replaced since manufacturing, some not.

At the very end of the board on input side is a KIA7812A and a KIA7912PL

On the output side there is one KIA7915P and one KIA7815A.

Wondering if anyone has a schematic for the board or can just tell me what fets/drivers SHOULD be in there as it looks like someone did some replace only the 'bad' repairs. I plan to remove and replace all Fets, drivers and gate resistors as a project to learn more about fixing amps. Ive got a decent knowledge for electronics and how they function and am a proficient solderer.

As soon as I get the board fully removed from case I will post photos.

Thanks in advance!

Click to read more...

 

[bmf85]

As promised, pics.

Once I had the board removed I noticed a couple of suspect Caps as well. There seems to be no damage to the board itself or anything other than the 2 caps, one fet for sure and one resistor but as stated I plan to change all fets and corresponding resistors to be safe.

Left to right the photos are.

Fried Fet

Entire board

1 suspect cap

Other suspect Cap

 

[keep_hope_alive Premium Member]

It appears someone failed a repair, which is worse news. Looks like they only replaced the failed parts without discovering the real problem.

Have you purchased the Amplifier Repair tutorial from BCAE1.com? If not, I recommend it before going further.

Rich V.

 

[bmf85]

That, essentially, was my assessment as well. I fully intended to do fill diagnosis but was hoping to learn the original Fet/driver numbers in order to order them as I plan on replacing all of them as should have been done originally. I'll look into that repair book, thanks.