Reinstall the removed parts in reverse order to see if it will stay on.
While it's on, make a complete list of the voltages on the MCU. Do this first.
While it's on, make a complete list of the voltages on the MCU. Do this first.
So the audio slowly degraded and faded now its back to audio on for 3 seconds and off again.
I reran the solder on all the surrounding smd resistors and its still the same.
Could it be a bad capacitor near the mcu?
I reran the solder on all the surrounding smd resistors and its still the same.
Could it be a bad capacitor near the mcu?
I don't know what the problem is, it could be a bad cap but it's a longshot if you haven't seen evidence of bad capacitors.
Can you repeatedly power up the amp to get the voltages when the amp is playing? It's likely only one or two that are changing.
Are you sure that you aren't starving the amp for current?
How much does the current draw change when the amp is playing and when it's silent.
Can you repeatedly power up the amp to get the voltages when the amp is playing? It's likely only one or two that are changing.
Are you sure that you aren't starving the amp for current?
How much does the current draw change when the amp is playing and when it's silent.
My power supply has 40 amps at 13.5v never had issues with other amps.
I'll try reading the voltages on mcu
I'll try reading the voltages on mcu
Some people feel the need to starve every amp for current to prevent damaging components and it causes problems. I just wanted to confirm that it wasn't an issue here.
The amp has started fluctuating randomly squeling via the speaker and it draws excessive current when this happens.
Power supply has also began tripping into protection.
Turning the idle fully counter clockwise stops the fluctuation
Power supply has also began tripping into protection.
Turning the idle fully counter clockwise stops the fluctuation
Do you think the bias pot is intermittent and causing the over-current protection circuit to engage/trip?
Could be ill try clean it.
Also I tested all the pins on mcu
Pin 44 has 5v when producing audio then drops to 0v when audio cuts
Also I tested all the pins on mcu
Pin 44 has 5v when producing audio then drops to 0v when audio cuts
Replaced missing component and the audio has gone again.
Think I'll put this one on aside for a few days for now.
Thank you for all your knowledge and support Perry.
Think I'll put this one on aside for a few days for now.
Thank you for all your knowledge and support Perry.
Q101 will likely restore audio, if removed.
Could the amp have been working better (for a short time) because the solvent you used was still moist on the board?
Could the amp have been working better (for a short time) because the solvent you used was still moist on the board?