Viper 2500.1

[S Merlington]

This amp had shorted outputs on 1 side of the amp..

I replaced the outputs and when trying to power the amp up it draws excessive current..

I flipped the audio driverboards around thinking 1 is defective but amp still draws excessive current..

If i put outputs in 1 side of the amp and power it up with both driverboards in place amp powers up and idles fine..

If i start putting outputs on the other side of the amp 1 by 1 it will draw excessive current doesnt matter which location i put them in..

does the board with the F16 and B52 IC's have anything to do with the drive signal??

Or do you have any ideas on what to check??

 

[Perry Babin]

Post a photo of the driver board with those ICs.

 

[S Merlington]

Heres a couple of pics of the board

 

[Perry Babin]

For the 3-pin connector, 1 should be ground and the other two should connect to pins 9 and 11 of the B52 IC. Confirm that this is true for that board.

 

[S Merlington]

Yeah thats correct

 

[Perry Babin]

Reinstall this board and remove the driver boards. Post the DC voltage on pins 9 and 11 of the B52 IC.

 

[S Merlington]

Pin 9:2.80
Pin 11:2.78

 

[Perry Babin]

They should not both be positive. If they are both positive and pin 9 has approximately -2v, replace the IC (LM361).

 

[S Merlington]

Ok heres what i get on the pins

Pin 9:2.78
Pin 11:-1.72

Is this IC ok or should i replace it?

 

[Perry Babin]

What changed from the previous readings?

Do you have full rail voltage on the center leg of all of the installed outputs?

 

[S Merlington]

I must have been not touching the pins good enough or reading the wrong pins from the last post..


I will power the amp up and check the voltages on the outputs

 

[S Merlington]

I get 0.00 volts on all center legs of the outputs..

On the FB31N20D's i get -59.6 volts on legs 1 and 3 on all of them

On the IRF9640's i get 59.6 volts on legs 1 and 3 on all of them

 

[Perry Babin]

Solder a bridge between legs 13 and 14 of the TL074 on that board. Do you get a square wave out of pins 9 and 11 of the B52 IC?

 

[S Merlington]

Yes i get a nice square wave on both pins 9 and 11

 

[Perry Babin]

Then the problem is beyond this board. Don't forget to remove the solder bridge.

 

[toprak]

JBL1201.1 circuit, TL074,LM361 and Triangle CD4060 series

 

[S Merlington]

I dont get this amp All drivers test fine on both boards..

It doesnt matter what driverboard i put in which location..

If i put 1 output fet in at a time in theese locations the amp will draw current and blow the outputs..

Any ideas what to check ?


I know i have to clean the pads up yet for the outputs i checked for solder bridges found nothing ..

 

[S Merlington]

Anyone have any ideas?? See post above

 

[timwebb]

The diodes and 1ohm resistors ok?