Rockford Fosgate BD15001 stuck in protect

[seankane]

Hello again Perry.

I have a bd 1500 stuck in protect.

I tested pin 6 of U21 and I read 8.20 vdc.

Where should I go next ?

[Perry Babin]

What work have you done to this amp?

Post the DC voltage on all pins of that IC.

U21
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:

[seankane]

[QUOTE=Perry Babin;2523732]What work have you done to this amp?

Post the DC voltage on all pins of that IC.

U21
Pin 1: 8.76 vdc
Pin 2: .771 vdc
Pin 3: 8.18 vdc
Pin 4: -0.029 vdc
Pin 5: 4.99 vdc
Pin 6: 8.21 vdc
Pin 7: 1.230 vdc
Pin 8: 9.64 vdc


I checked the drive circuit and all looks very nice, very nice crisp square form, and checked the ohm readings between first and last gate legs in all pairs all read 20 ohms.

Checked ohm reading from last leg of Q101 to positive speaker terminal, and it read 0.1 ohms. Wiggling the output inductor coil makes no change.

I checked the waveform on pins 1 and 7 of Ull and they are identical like a heart beat on the EKG again, no triangle or square like they shouls be.

So far thats all I have done i was going to run a sine wave and look at the output signal on pin 1 of U4 but have not got that far.

The board looks like new no dust, no repairs, absolutely immaculant.

[Perry Babin]

You're missing the negative regulated voltage. I think the regulator is the one labeled Q16.

[seankane]

Originally Posted by Perry Babin

You're missing the negative regulated voltage. I think the regulator is the one labeled Q16.

Ok I dont remember checking it on the other amp. I will look for Q16, you need the dc voltage reading from Q16??

[seankane]

Q16 and Q15 LM337 amd LM317? Those 2 are very warm to the touch. Where do I test the voltage on the Q16 which legs?

[Perry Babin]

Leg 3 of the 337. The 317 is the positive regulator.

[seankane]

Originally Posted by Perry Babin

Leg 3 of the 337. The 317 is the positive regulator.

Any particular probe configuration?

[Perry Babin]

Black probe on amp ground. Red probe on the regulator.

[seankane]

Originally Posted by Perry Babin

Black probe on amp ground. Red probe on the regulator.

Ok thats what I thought so the source leg of that regulator started at -0.075 vdc and bled down rapidly to - 0.031 vdc and seemed to hold there.