Hi all
This amp going into mute with no reason. Checked opto and replaced and also the transistors connected to it all are fine. There are totally 3 npn that are responsible for muting. Collector of one is connected to the remote with 24k resistor and the same is connected to the base of another npn. If I short the opto and release the output is enabled and stays good until the amp switch off then it mutes again. I changed the resistor from 24k to 2k and everything works normal. But I know it is not correct. Any suggestions will be highly appreciated. From rca shield to terminal ground I am having 3v.
This amp going into mute with no reason. Checked opto and replaced and also the transistors connected to it all are fine. There are totally 3 npn that are responsible for muting. Collector of one is connected to the remote with 24k resistor and the same is connected to the base of another npn. If I short the opto and release the output is enabled and stays good until the amp switch off then it mutes again. I changed the resistor from 24k to 2k and everything works normal. But I know it is not correct. Any suggestions will be highly appreciated. From rca shield to terminal ground I am having 3v.
Attachments
What's the DC voltage across the output side of the optocoupler before the end of the mute delay?
If the rca ground is connected to the main terminal ground then the amp functions normal. The resistance between rca ground and main ground is 1k. If I short this then amp functions normal.
What's the resistance between the primary and secondary ground?
Amps tend to be designed to have a grounded shield. Most head units have a grounded shield. Was the amp having the same problem in the vehicle with a standard head unit?
Amps tend to be designed to have a grounded shield. Most head units have a grounded shield. Was the amp having the same problem in the vehicle with a standard head unit?
Resistance is 1kohm between primary and secondary ground.
Yes when rca is grounded it working good.
If owner wants to jack in using phone the amp will not come out of mute. So he can't play music using phone.
Yes when rca is grounded it working good.
If owner wants to jack in using phone the amp will not come out of mute. So he can't play music using phone.
No he is not switching. He just tried this amp which was not being used for a while using his phone with auxiliary to rca cable and battery. And he found it was not playing so he brought to me to fix.
Since the phone has no ground (except maybe when charging), you could ground the RCA shields.
If the phone gets ground through the charger, that could be the solution (to keep it charging when in use). This would eliminate the need for grounding the RCAs.
If the phone gets ground through the charger, that could be the solution (to keep it charging when in use). This would eliminate the need for grounding the RCAs.