Rockford Fosgate 240x4 dsm

[RockfordFIx]

Hey Perry,

I have a Rockford Fosgate 240x4 that will not power up. I have checked all the outputs and powersupply fets are good. Amp seemed in decent shape. However, the U1610 and U1620R had burn marks and were missing the 2.7ohm resistors. I have applied power to the remote connection and connected the ground and only have about 0.412 vdc on the powersupply center legs.

 

[RockfordFIx]

I made an error in my posting. With power on remote connection and ground connected I have 0.4vdc on pin 1(gate). I also have no voltage on VCC of the TL494 ic

 

[Perry Babin]

Post the voltage on the resistors R1, R2 and R3, black probe on ground.

 

[RockfordFIx]

R1=14.74,8.70
R2=4.619,8.70
R3=4.618, 0.00

 

[RockfordFIx]

I also only have 0.12vdc on vcc for the lm339

 

[RockfordFIx]

Perry I just found my problem working the schematic backwards for vcc voltage. I starting to lose my eyesight thank goodness for magnifying glass and zoom. I had a broken trace at the remote connection.

 

[Perry Babin]

Cheap 'cheater' glasses from Walmart do wonders. $7 for 3 pairs.

Soldering alone won't be reliable. I'd run a wire from the terminal to D2 and R1 as well as fixing the terminal, mechanically, to the board.

 

[RockfordFIx]

I actually used the square wire lead from a LED and wrapped D2 and connected it by wrapping terminal as well.