Solder pin 5 back to the board (on top is OK) and after the amp comes out of muting, short pins 3 and 4. Does it go in and out of muting quietly?
yes it is going in and out of muting quietly, no pops.
Is pin 7 of 302 transitioning instantaneously after the mute delay and when the remote is removed?
Does the pop occur (normally) every time the amp is switched off or only after it's switched on/off quickly (as when the vehicle is started)?
just after the mute pin 7 read 3.6v and as soon as remote removed it went back to zero.
the pop occurs every time the remote is removed.
Is pin 7 of 302 transitioning instantaneously after the mute delay and when the remote is removed?
Does the pop occur (normally) every time the amp is switched off or only after it's switched on/off quickly (as when the vehicle is started)?
Is there anything I can do to find out this dc pulse? Are any capacitors leaking?
Is pin 7 of 302 transitioning instantaneously after the mute delay and when the remote is removed?
Yes it is transitioning quick.
Quick isn't instantaneous. If looking at the voltage on your scope, the voltage should go from high to low and low to high as a straight vertical line.
yes i just checked with scope it is a straight vertical line. it is changing instantaneous.
Attachments
Last edited:
If it was quiet when you shorted the pins of the opto-coupler, it should mean that everything beyond the opto-coupler is OK. This drives the opto-coupler and is switching as it should. Q305 and a couple of resistors are the only things between the comparator and the opto-coupler.
If it was quiet when you shorted the pins of the opto-coupler, it should mean that everything beyond the opto-coupler is OK. This drives the opto-coupler and is switching as it should. Q305 and a couple of resistors are the only things between the comparator and the opto-coupler.
i have changed 302 and Q305 and it solved the problem. both actually looks fine but dont know what was the problem. big headache gone. Thank you very much for your time and kind help.
Is it possible that the fan being connected was causing the problem all the time?
Going back and checking the things we checked earlier, which change with the fan connected?
With nothing connected to the amp and the fan unplugged, what's the resistance from pin 13/15 to pin 12 on the SG3525?
Going back and checking the things we checked earlier, which change with the fan connected?
With nothing connected to the amp and the fan unplugged, what's the resistance from pin 13/15 to pin 12 on the SG3525?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
- Home
- General Interest
- Car Audio
- Power Acoustik A3000db - DC on output while remote off