Rockford Fosgate BD10001

[seankane]

Hello everyone.

I recieved this amp today in "non working" condition. I bought it from a guy that said it worked great until he took it to a "guy" to have it installed. Later he recieved a call and the "guy" said it didnt work but was willing to sell him another amp.

I removed the cover and found the power supply completely burned to a crisp. All the p/s fets and gate drivers. The MPSA56's were all fried to.

The output stage had 6 blown fets. Someone had taken solder and globbed it all over the legs of the output fets as to short them out.

I replaced all 8 IRF3205 p/s fets. I replaced 8 10 ohm gate drivers. I replaced 4 MPSA56's. Thats all I have done in the power supply.

I replaced the 6 output fets 3 IRF6215's and 3 IRF3415's. I replaced all 6 gate drivers for these mosfets as well.

I then tried to power the amp and full short drew 60 amps on my power supply. The output fets that I replaced were giving me really odd resistance readings. I replaced the LM337 and the LM317 and still got the same readings. I noticed the gates for the output fets that were really burned were directly tied to the mosfets driver MIC4420CT. I replaced the mosfet driver "thanks Perry" and now the output fets read like the existing ones in the channel.

My question would be is there something else I should be checking before I attempt to power up the amp and test it. I dont want to do any un needed damage. Any help would be great.....thanks again.

[seankane]

OK I tried powering up amp with same result drew 60 amps on my power supply like it was shorted.

At this point I am not sure if it is in the output or the power supply.

Is it R35 that disconnects the power supply from the output?

[seankane]

The MPSA56 are the driver transistors for the power supply correct me if I am wrong?

If the first time I powered the amp and another component was bad could it have taken one or more of those out again?

Do I have to remove R35 and R31 to completely disconnect the output from power supply?

[Perry Babin]

The drivers for the power supply are two MPSA06s and two MPSA56s.

The easiest way to disconnect the audio amp from the power supply is to desolder (after discharging) the red/black wires. Desolder the end nearest the rectifiers.

[seankane]

Well thats what I get for getting in a hurry and not reading the schematic. I have MPSA56's installed in all 4 spots.

Would that make it short on powering up? Should I change all 4 again due to the A56's might be damaged now?

[Perry Babin]

I would replace all 4.

I don't know if that would cause it to draw excessive current.

[seankane]

Well you and I can both make a note that does cause it to short. I replaced all 4 with the correct parts and it powers up and idles fine. I will check for audio and post my result.

[seankane]

The amp sounds clean and POUNDS my 18" test sub.

Thanks for your help Perry. Did you check your e-mail??

[Perry Babin]

The last thing I see from you was the notice about the driver boards. Was there something else?

I often don't reply if there isn't a question.

[seankane]

No just wanted to be sure you got it, the rest will be coming soon. The HD stuff we discussed.