Orion XTR PRO 2400

[Perry Babin]

Is the drive signal on the gate pads going all of the way to ground (scope must be on DC coupling and the trace aligned to the reference line)?

 

[caraudioguy2100]

This is what I get on the gate pads I haven’t loaded them yet this is before loading them with a cap .

Scope setting are 5us 5volts/div

 

[Perry Babin]

That looks OK. Now post one with the cap. Check all banks.

 

[caraudioguy2100]

I forget does the cap go between gate and source or drain and source ?

 

[Perry Babin]

Gate and source.

 

[caraudioguy2100]

This is what I get when it’s loaded with a 0.1 cap .

I get the same results with all of the banks of fets

Scope is 5ms 5volts/div

 

[Perry Babin]

That looks OK. Was it blowing FETs in all 4 banks?

 

[caraudioguy2100]

Yes it was blowing the fets in all 4 banks as soon as I applied remote a fet would blow I cut the bad fet out and try powering it up again and it would blow another fet .

It did this in all 4 banks .

Wondering if I have a intermittent short or a bad solder connection on the driver board .

 

[Perry Babin]

It's possible that a ground connection is intermittent. That's why it's so important to use ChipQuik.

Re-check all 4 banks and while watching the drive at the FETs (with the cap), move the driver board to see if the drive signals ever change.

 

[caraudioguy2100]

I can’t get the drivers be signals to change while wiggling the driver board and pushing on various points of the board .

I never removed the power supply driver board the problem was with the output section .

I will replace the fets and see what I come up with

 

[Perry Babin]

Work through a current limiter to see if that will save the FETs and possibly find the fault.

 

[Hexhclass]

Here is what I get on the 494

Pin 1:4.99
Pin 2:0.05
Pin 3:0.00
Pin 4:1.47
Pin 5:3.73
Pin 6:0.00
Pin 7:13.47
Pin 8:4.96
Pin 9:5.30
Pin 10.5:30
Pin 11:13.47
Pin 12:13.47
Pin 13:4.99
Pin 14:4.99
Pin 15:4.99
Pin 16:0.00

13.47v on pin 7 error?

 

[Perry Babin]

All of the first side are wrong.

 

[caraudioguy2100]

I believe I had the pin order right I will re check this tonight and post the results

 

[caraudioguy2100]

I’m double checking the 494 voltages and I know the pin order is correct . Here is what I get .

Pin 1:4.99
Pin 2:0.05
Pin 3:0.00
Pin 4:1.47
Pin 5:3.73
Pin 6:0.00
Pin 7:13.33
Pin 8:4.91
Pin 9:5.35
Pin 10:5.25
Pin 11:13.33
Pin 12:13.33
Pin 13:4.99
Pin 14:4.99
Pin 15:4.99
Pin 16:0.00

There are no fets in the amp right now .

Isn’t pin 7 suppose to be 0 volts why do I get 13 volts on it ? I’ve triple checked the pin order

 

[Perry Babin]

Here's the problem. If you have 5v on pin 14, there is virtually no way that you can have 13v on pin 7.

If you had 5v on pin 1, and 0v on pin 2, pin 3 would be at something near 5v.

Pins 8 and 11 are directly connected and they would have the same voltage.

 

[caraudioguy2100]

Ok I guess I need to go back to school and learn how to look at the ic
I was measuring voltages from the back side of the power supply board and you are correct I had the pin order wrong .

I skipped over pin 1 and thought pin 2 was pin 1 so pin 8 was also skipped over .

I believe the ic is working correctly once the new fets come in I will replace them and power it up with a current limiter to see if I have any further issues

 

[caraudioguy2100]

Got the new fets today .

I installed them and so far so good .

How long should I let the amp idle to make sure the fets are gonna survive ?

No outputs are installed yet

 

[Perry Babin]

First of all, clamp everything down to the heatsink.

Then I'd push/pull/twist everything, before and after heating/cooling various components. This is extreme but having the PS FETs blow one by one is odd. The only time I remember anything similar was on the larger Rockford amps like the old 800a2. That was due to driver issues.

 

[caraudioguy2100]

This amp sucks .

I checked the drive signals on the outputs all appear good .

I put try outputs back in the amp and clamped everything down.

The amp will power up and idle for about 20 secs then it just starts blowing outputs .

I don’t get it all of the transistors on the driver boards are brand new .