Hifonics BXI1500D Help

[rhempz01]

Pin 6

#6 on the 4080

 

[rhempz01]

4080 still gets hot quickly when the amp is turned on as well.

 

[Perry Babin]

Does having the 4080 in the circuit change that waveform?

What is the DC voltage on pin 8 of IC4C and IC3C?

 

[rhempz01]

That is with the 4080 in circuit.
Ic4c
8.) 7.64

Ic3c
8.) 7.65

 

[Perry Babin]

The 4080 may be damaged, again.

Remove it and recheck the waveform on pin 6 of the 4080 and the DC voltage on pin 8 of the two op-amps.

 

[rhempz01]

Jumper is still in place on IC4C and 4080 is removed
IC3C & IC4C

8.) 12.55vdc

 

[Perry Babin]

I think the 4080 failed when installed with the shorted output.

 

[Lenin89]

4080 is easy to find and cheap enough. Even easier to change. Just get a new ones. It will save You some time.

 

[rhempz01]

will the 4081 work as well? And i replaced it with a new 4080. Amplifier draws normal current and the 4080 does not heat up. Still no audio at the speaker terminals?

 

[Perry Babin]

The 4081 is different.

As with all class D amps with no audio, do you have rail-rail oscillation?

 

[rhempz01]

no oscillation. found one diode shorted out. i changed it, it made no difference.

 

[Perry Babin]

OK, we go back to the input pins. Do you still have a triangle waveform?

Do you still have 12v on pins 15 and 16?

If so, post the DC voltage on all pins:


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:
Pin 17:
Pin 18:
Pin 19:
Pin 20:

 

[rhempz01]

yes triangle is present. when i tested the voltages of 15& 16 it was only 9.65vdc and 15 sent the amplifier into protection when i turned it back on one or two of the power supply mosfets were smoking? very hot.

 

[rhempz01]

found another shorted output at the location of the replaced diode. checking for out of tolerance resistors or diodes.

 

[rhempz01]

Q9C1 keeps shorting out. r33c is a 4148 correct?

 

[rhempz01]

output area in question.

 

[Perry Babin]

Yes.

 

[Perry Babin]

One other thing. Probing 15 and 16 should have caused the same behavior (none). Make sure that none of the inserts in the socket have pulled out like the one in the image below.

 

[rhempz01]

all clear and im going to go through the power supply real quick, without the 4080 and make sure its all clear. i replaced the 65n06 in that bank with ones i had here.

 

[rhempz01]

4080 socket voltages.

Pin 1: 11.69
Pin 2: 11.98
Pin 3: -.465
Pin 4: -.469
Pin 5: .005
Pin 6: 6.112
Pin 7: 6.219
Pin 8: -.432
Pin 9: -.432
Pin 10: 11.76
Pin 11: -4.27
Pin 12: 1.778
Pin 13: -.432
Pin 14: -.447
Pin 15: 12.02
Pin 16: 12.03
Pin 17: -.447
Pin 18: -.430
Pin 19: 6.442
Pin 20: -.428