I am repairing this amp and having issues on power supply.
Fets are removed a few resisters were replaved along with 4n25 and lm358.
All 4401 and 4403 drivers were replaced.
i have no drive for pin 14 on sg3525.
voltages on 3525
1: 0.920
2: 1.022
3: 0.015
4: 0.209
5: 2.086
6: 3.780
7: 2.12
8: 4.82
9: 4.89
10: 0.062
11: 2.593
12: 0.006
13: 3.615
14: 0.042
15: 13.46
16: 5.10
The scope signal on pin 11 is attached.
Fets are removed a few resisters were replaved along with 4n25 and lm358.
All 4401 and 4403 drivers were replaced.
i have no drive for pin 14 on sg3525.
voltages on 3525
1: 0.920
2: 1.022
3: 0.015
4: 0.209
5: 2.086
6: 3.780
7: 2.12
8: 4.82
9: 4.89
10: 0.062
11: 2.593
12: 0.006
13: 3.615
14: 0.042
15: 13.46
16: 5.10
The scope signal on pin 11 is attached.
Attachments
If there isn't a solder bridge between 12 and ground, the IC is likely defective.
If you attempt to remove the IC, clip the leads at the body of the IC, remove the body and then desolder the legs without touching the board with the tip of the iron (heating the leg from the IC only). Add new solder if the leads don't come out easily. These boards are EXTREMELY easy to damage. Avoid touching the pads on the board if at all possible.
If you attempt to remove the IC, clip the leads at the body of the IC, remove the body and then desolder the legs without touching the board with the tip of the iron (heating the leg from the IC only). Add new solder if the leads don't come out easily. These boards are EXTREMELY easy to damage. Avoid touching the pads on the board if at all possible.
