Another Rockford Fosgate Punch 200ix repair
 

OK, typed a nice long post only to get sent back to the login screen when posting...:censored:

Anyway - short version, bought a 200ix on eBay 3-4 years ago from reputable seller. Never tested amp until today (I know, dumb...). Just saw the tamper stickers were torn, so I decided to take a peek and found this atrocity:

http://rigs.corequipment.com/Cebby/A...ix-hackjob.JPG

Click for high res of full board - great for zooming in :)

All I found was a PDF schematic, not a PCB layout and am having a little trouble reading it.

I'd like to salvage this amp - it has some brothers to play with...

Any guidance would be greatly appreciated!

The board location is D10. The part number is a Motorola IN4003.

It also looks like but hard to tell because the flash from your camera on the board that your driver transistors for the power supply are burned.

I cant tell for sure these are board location Q2, Q3, Q4, Q5.

These will have markings of 1A or 1AM and the others will be a 2A.

The 1A or 1AM will be part number: MMBT3904
The 2A will be part number : MMBT3906

Does the amp power on or produce audio?

Amp powers on, but the power LED is dim compared to my other working Punch amps. No audio.

More pics
 

I took more shots of the business end...sort of a walk-around and a few close ups at the end.

Pic 1
Pic 2
Pic 3
Pic 4
Pic 5
Pic 6
Pic 7
Pic 8
Pic 9

What do you have for tools and test equipment?

Sounds like you have a partial power supply failure. At this point I would rebuild the whole power supply.

Do you at least have a multimeter?

Yes, I have a Fluke 115 multimeter, various soldering irons, etc. No scopes or anything like that though.

Set your meter in ohms with the range on auto and measure the rsistance between the gate and source legs of all 4 power supply fets. That would be leg 1 and 3 looking at the fet from left to right, what do you get?

The board location of these fets is Q10,Q11,Q6,Q7

Next measure the gate drivers resistance the little smd resistors marked 510 what do you get? These are 51 ohm and should read somewhat close to that.

The board location of these resistors is R31,R36,R32,R37

Post your results then we will check the gate drive voltage of the power supply fets.

As a side note...

On this site (and others), if you type anything that would take more than 1 minute to re-type, highlight the text and copy it to the clipboard (ctrl-c or right-click and select copy) before clicking anything that will move you from the page where you typed it. It's happened to me so many times that I always do this for long posts.