Fosgate 1001BD stuck in protection

[Rabbi]

Amp is stuck in protection mode.

here is my U14, Does this look correct? (UC3526N)

1 = 4.88
2 = 3.70
3 = 4.76
4 = 4.64
5 = 4.80
6 = 0.00
7 = 0.00
8 = 4.41
9 = 3.62
10 = 1.92
11 = 0.00
12 = 4.58
13 = 6.51
14 = 15.29
15 = 0.00
16 = 6.52
17 = 15.26
18 = 4.95

[Perry Babin]

U21 is the most likely suspect. Post the DC voltage on all of the pins of U21.

[Rabbi]

U21

-----

1= -8.17
2= 7.61
3= -8.73
4= -9.52
5= 4.94
6= -3.41
7= 8.20
8= 9.51

[Perry Babin]

Replace it.

[Rabbi]

Thanks perry, will do.

Might i ask what exactly this IC controls or does?

Thanks

[Perry Babin]

It's used to shut the amp down when there is over-current and is also responsible for the mute delay. These ICs commonly fail in a way that causes the inverting input (pin 6) to leak to the negative power supply for the IC. When pin 6 is negative, you know that the IC has failed.