HIFONICS ZXi 1008 car amp stuck in protect mode

[tscr2015]

if U1 is bad what would happen?

 

[tscr2015]

Put the rectifiers back in the amp ..

Remove U1 that sits behind the driverboard ..

Insert a 10 amp fuse in series with the B+ wire ..

Try powering the amp up dies this allow the amp to power up?

Only try powering it up for a few secs since it may draw current so remember to insert a 10 amp fuse in the B+ line

all steps completed. Powered up...Protect light on.

ok so now what do I check?

Thanks and Happy Holidays
Tom S.

 

[tscr2015]

Could the driver board be causing the problem or the transistors (that sit in front of it cause a problem if they are bad?)

Thanks and Happy Holidays,

Tom S.
Wells, MN

 

[tscr2015]

What should the readings on U1 the optical coupler be?

 

[tscr2015]

just pulled all of the rectifiers and the protect light is still on. Now what?

 

[S Merlington]

I think you have a component that is bad on the power supply driver board

I just fixed a crunch amp with same issue

 

[tscr2015]

which component was bad on yours? I don't have the correct equipment to replace anything that is that small. Any chance you got a schematic on that amp if so PM me?

 

[tscr2015]

can you help me figure out why this amp is still in protect mode?

 

[S Merlington]

post the voltages on all 16 pins of the power supply IC on the driver board b careful not to let the probe slip between pins.. Black probe on amps ground terminal.. It's either a 494 or 7500 IC can't remember which one the amp uses

Post as followed

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:

 

[tscr2015]

post the voltages on all 16 pins of the power supply IC on the driver board b careful not to let the probe slip between pins.. Black probe on amps ground terminal.. It's either a 494 or 7500 IC can't remember which one the amp uses:

power supply control IC is a IL494D. See attached datasheet.

Pin 1: 2.7v
Pin 2: 4.53v
Pin 3: 4.6v
Pin 4: 18.2v
Pin 5: 1.55v
Pin 6: 3.4v
Pin 7: .1mv
Pin 8: 12.09v
Pin 9: 0v
Pin 10: 0v
Pin 11: 12v
Pin 12: 11.21v
Pin 13: 5.02v
Pin 14: 5.02v
Pin 15: 5.02v
Pin 16 7.8vv

 

[S Merlington]

Are you sure pin 4 is 18 volts ?

If so something is driving pin 4 high also pin 16 is being driven high

 

[tscr2015]

oops pin 4: 18mv

had to check twice

 

[S Merlington]

I forget if you pull the rectifiers the amp will still protect ?

 

[tscr2015]

yes it is in PROTECT with rectifiers out.

 

[S Merlington]

Are you sure you have no solder bridges between pads for the outputs or the pads for the drivers?

What is the voltage on all 3 legs of the power supply fets ? Check 1 per side and post the voltages as follows

Leg 1:
Leg 2:
Leg 3:

Other side

Leg 1:
Leg 2:
Leg 3:

 

[tscr2015]

Are you sure you have no solder bridges between pads for the outputs or the pads for the drivers?

What is the voltage on all 3 legs of the power supply fets ? Check 1 per side and post the voltages as follows

Leg 1: 0
Leg 2: 12v
Leg 3: 0

Other side

Leg 1: 0
Leg 2: 12v
Leg 3: 0

 

[tscr2015]

also check for solder bridges with a magnifying glass could not find any.

 

[S Merlington]

Pin 16 is high ..

Pin 16 should be at 0.00 volts..

So if you have no solder bridges anywhere I'm guessing the problem is on the driver board ..

i can help you more when I get home

 

[tscr2015]

ok be waiting to hear back from you. Thank you again for the help

 

[S Merlington]

Check the diodes DZ60 and DZ61 they sit on the main board behind the driver board .

What do they read ?