First pic is of Q500,501
2nd pic is of Q502,503
3rd pic Is of Q504,505
4th pic is of Q50,507
I think the problem is with Q500,501
Scope set to 5us 2 volts/div this is with a loading cap
2nd pic is of Q502,503
3rd pic Is of Q504,505
4th pic is of Q50,507
I think the problem is with Q500,501
Scope set to 5us 2 volts/div this is with a loading cap
Attachments
With the loading cap in place and the scope with the same ground, what does the output of U5 look like?
I have a bad gate resistor . After I replace it I think the drive will be normal but the issue still remains with the dc across the speaker terminals.
Since all outputs and gate resistors were fine before it blew some of the outputs and the voltage was there
Since all outputs and gate resistors were fine before it blew some of the outputs and the voltage was there
Are you saying that you currently have voltage (how much?) across the speaker terminals with no output FETs?
If you ground them through the lamp (individually), what's the DC voltage measured across the lamp?
So do I use the amps ground terminal for 1 lead on the lamp and the other on the source pad ?
Or how do I hook this up and measure the voltage
Or how do I hook this up and measure the voltage
So do I use the amps ground terminal for 1 lead on the lamp
^^ Yes
The other lamp terminal will go to each of the individual speaker terminals
^^ Yes
The other lamp terminal will go to each of the individual speaker terminals
With the lamp connected I get 0.00 volts measured across the lamp for all speaker terminals .
When I have 1 lead from the lamp grounded when I touch the other lead to the speaker terminal I get a small spark on the speaker terminals
When I have 1 lead from the lamp grounded when I touch the other lead to the speaker terminal I get a small spark on the speaker terminals
When you ground, then remove the lamp, does the voltage on the individual speaker terminals immediately rise?
If so, to what, for the positive and negative terminals?
If so, to what, for the positive and negative terminals?
As soon as I disconnect the the lead on the speaker terminals the voltage instantly goes back up .
On the positive speaker terminals it is 69 volts
On the negative speaker terminals it’s 128 volts
On the positive speaker terminals it is 69 volts
On the negative speaker terminals it’s 128 volts
I can't be sure but I think that something may be leaking on the driver boards.
Pull one of the driver boards and see if the problem is eliminated.
Pull one of the driver boards and see if the problem is eliminated.
I pulled 1 driver board and the voltage on the positive speaker terminals dropped to 10 volts
I pulled the other board and the voltage is gone on both positive and negative speaker terminals
I pulled the other board and the voltage is gone on both positive and negative speaker terminals
Check the value of all resistors on the driver boards.
Also check the diodes on those boards for leakage (will have to be be removed to check for leakage).
Also check the diodes on those boards for leakage (will have to be be removed to check for leakage).