Hi all, trying to repair a Clarion Apa4300 amplifier.
When attempting to power up the digital panel lights up,
The power on led stays off.
No audio output.
On internal inspection Q143 tested 0 ohms across all 3 legs so I removed it along with Q144
I've tested TL594, all measurements in DCV pins 1-16
1, 0
2, 4.9
3, 0
4, 0.1
5, 1.5
6, 3.6
7, 0
8, 12.9
9, 6.2
10, 6.2
11, 12.9
12, 12.9
13, 4.9
14, 4.9
15, 4.9
16, 3.5
Also checked dc voltage on Q812
1, 12.65
2, 13.6
3, 13.3
Apologies I had already started a post on this amp but my meter was on the wrong setting leading to much confusion so I've started a fresh thread.
Hopefully I can get the amp up and running again, and thank you Perry for your patience and support.
When attempting to power up the digital panel lights up,
The power on led stays off.
No audio output.
On internal inspection Q143 tested 0 ohms across all 3 legs so I removed it along with Q144
I've tested TL594, all measurements in DCV pins 1-16
1, 0
2, 4.9
3, 0
4, 0.1
5, 1.5
6, 3.6
7, 0
8, 12.9
9, 6.2
10, 6.2
11, 12.9
12, 12.9
13, 4.9
14, 4.9
15, 4.9
16, 3.5
Also checked dc voltage on Q812
1, 12.65
2, 13.6
3, 13.3
Apologies I had already started a post on this amp but my meter was on the wrong setting leading to much confusion so I've started a fresh thread.
Hopefully I can get the amp up and running again, and thank you Perry for your patience and support.
The IC is producing output. Confirm that you have ±rail on the output transistors and ±regulated voltage on the op-amps.
Do you still have 6v on pins 9 and 10 of the 494?
What is the DC voltage if you place the black probe on pin 4 of the op-amp and the red probe on pin 8?
What is the DC voltage if you place the black probe on pin 4 of the op-amp and the red probe on pin 8?
What is the DC voltage if you place the black probe on pin 4 of the op-amp and the red probe on pin 8?