Rockford Fosgate T5002

[mike49504]

I got another one of theese in for repair..

The problem with the amp is it will keep cutting out and going into protection mode ...

If you have the crossover on full range or high pass and listen to midrange speakers the amp is fine..

If you connect a subwoofer to the amp and set the crossover to low pass the amp will go in and out of protection mode..


Hooked this amp up in several different cars and several different subs also amp will go in and out of protection mode when the low pass crossover is on and a sub is connected...


Any ideas??

[seankane]

Sometimes these switches can short. With the switch in low pass is there any DC on the metal case of the switch itself?

Have you tried connecting a sub woofer to the amp in high pass and full range just to see what it does?

[Perry Babin]

What was the original problem?

What did you do to the amp to this point?

[mike49504]

This amp ive done nothing at all to it... Just got it in for repair..


The guy told me that it has always had the same problem with going in and out of protection mode when a sub is connected and he thought that maybe it was something in his car so he hooked the amp up in 3 different cars and hooked differnt subs up to it and has had the same problem with the amp ..


So he brought it to me to see if i could figure it out...

I can get the amp to do the same thing on the bench..

[Perry Babin]

It has two channels. If you have the speaker connected to only one channel at a time. does either or both cause the amp to go into protect?

[mike49504]

Both channels cause it to go in and out of protection

[EBBCO]

These amps have an issue with the switches in them, also check the RCA shell's on amp. Go from shell to the I.c chip, follow each trace, there not common. One comes undone it will cause lp mode to phase out 180 and protect.

[Perry Babin]

Post the DC voltage on all pins of U3 before it goes into protect. Add the voltages for the pins that change after it goes into protect.

U3
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:

[mike49504]

U3
Pin 1: 9.38
Pin 2: 14.31
Pin 3: 14.76
Pin 4: 0.22
Pin 5: 1.18
Pin 6: 0.01
Pin 7: 4.98
Pin 8: 0.58
Pin 9: 9.77
Pin 10: 0.11
Pin 11: 1.00
Pin 12: 0
Pin 13: 0.46
Pin 14: 4.97


Voltages when it protects

U3
Pin 1: 0.04
Pin 2: 13.94
Pin 3: 14.36
Pin 4: 0.54
Pin 5: 1.16
Pin 6: 7.00
Pin 7: 4.98
Pin 8: 0.59
Pin 9: 5.98
Pin 10: 0.30
Pin 11: 0.99
Pin 12: 0
Pin 13: 0.46
Pin 14: 4.97

[Perry Babin]

Remove R58 from the circuit. This will disable the shutdown circuit so you must be careful (15 amp fuse, transistors tightly clamped to the heatsink). I'm assuming that the amp will go into protect mode relatively easily and would not blow the 15 amp fuse.

Does the amp work as it should with the protection circuit disabled?