Help Rockford 1100a2

[stoke]

hi im new in this forum and i need a lil help on a RF 1100a2.. i replaced some IRF9640, IRF640, 0.1 ohm resistor and the LM337 regulator and the amp was playing fine with a lil noise... yestarday i disarm the amp again to check the source of the noise but when i turn on the amp with the current protection on the ground i see some current flowing and the Q5,Q6,Q13 and Q12 transistor are getting hot quickly..

i hope some one could help me on thise one..

PD. i dont have any osc. here just in my job and i will be free for a week

 

[stoke]

recheck....
Q5,Q6,Q12 and Q13 are not shorted and i got 5volts on gates

i don't have any voltage on the Rectifiers U7 and U5.

 

[Perry Babin]

What is the DC voltage with one probe on the center leg of U7 and the other probe on the center leg of U5?

 

[stoke]

neg probe on U5 and Pos on U7 center legs i got -7 volts

 

[Perry Babin]

Do you have 5v on the gates of ALL of the power supply FETs? Check each one.

 

[stoke]

yes

 

[stoke]

yes

i have 5 volts on all of then

 

[Perry Babin]

That would tend to indicate that the FETs are all OK.

You stated that you had the current protection on ground. Do you mean you had a current limiter connected to the ground terminal of the amp?

 

[stoke]

yes is a lil trick i learn to stop blowing things when you're testing

 

[Perry Babin]

Having the current limiter on ground can cause problems, particularly when you connect a signal source to the amp. Connect it inline with the B+ line instead.

What is the DC voltage measured directly across the B+ and ground terminals on the amp when you have only 7v DC across the two rectifiers?

 

[stoke]

10volts

 

[Perry Babin]

Do you have 5, 10 and 0v DC on every power supply FET?

Place the black probe on the ground terminal of the amp when measuring the voltage.

Did you have the black meter probe directly on the ground terminal of the amp when you measured the voltages previously?

 

[stoke]

yes all the measuring were make with black probe on ground.

with ground and remote i have 5volt on each gates of all power supply fet

with ground, batt and remote i just have 10volts on center leg the other two measure 0volts.

 

[Perry Babin]

with ground, batt and remote i just have 10volts on center leg the other two measure 0volts

Do you have 5v or 0v on the gate?

 

[stoke]

Do you have 5v or 0v on the gate?

i have 5volts when only ground and remote are connected

and 0volts when G, B and rem are connected

 

[Perry Babin]

Post the DC voltage on all 16 legs of the U1 (TL494) with the amp powered up (including remote voltage). Copy and paste the following into your reply.

U1
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:
Pin 15:
Pin 16:

 

[stoke]

ok. i will send you those measure on Friday. i'm working in some project and i will be out for 3 days.

 

[stoke]

hi again sorry for take so long.

U1
Pin 1: 0
Pin 2: 4
Pin 3: 0
Pin 4: 2
Pin 5: 0
Pin 6: 3
Pin 7: 0
Pin 8: 13
Pin 9: 0
Pin 10: 0
Pin 11: 13
Pin 12: 13
Pin 13: 4
Pin 14: 4
Pin 15: 4
Pin 16:0

 

[Perry Babin]

4v on pin 14 is well out of tolerance. The IC appears to be defective but don't replace it yet. Does U11 have 5v on pin 14?

 

[stoke]

could be the multimeter im using, i forgot my fluke 179 at job, but i get a cheap one from a friend

i will see what i can i get from u11