I have never encountered one of these before, but I got an A600.2 that has a red light only. Both rails are present, no shorted output transistors on either channel. I did notice one channel has 150mV of DC offset, whereas the other one is more like 13mv.
Maybe this is why the red light is stuck on, not sure.
Anyone have a schematic? thanks.
Maybe this is why the red light is stuck on, not sure.
Anyone have a schematic? thanks.
The offset can be adjusted with the pots near the LED.
Is the LED lens red or white?
Do you have audio reaching the driver board?
Do you have positive and negative rail voltage?
Do you have positive and negative regulated voltage on the power supply pins of the op-amps?
If you have the tutorial, the 6800 diagram in the PPI folder will be somewhat similar. If not, email me:
babin_perry@yahoo.com
Is the LED lens red or white?
Do you have audio reaching the driver board?
Do you have positive and negative rail voltage?
Do you have positive and negative regulated voltage on the power supply pins of the op-amps?
If you have the tutorial, the 6800 diagram in the PPI folder will be somewhat similar. If not, email me:
babin_perry@yahoo.com
Everything looks good as far as rails. Theres no sound at all, because the LED is stuck on red, and not green. It is a bi-color LED. the low impedence LED is yellow, and its NOT on. the bicolor LED is white.
I need schematics of the protection/muting circuit so i can figure out how to chase it.
I need schematics of the protection/muting circuit so i can figure out how to chase it.
They're marked J108 near the driver boards.
Do you have audio reaching pin 3 of the driver board?
Email me if you don't have the diagram I noted.
Do you have audio reaching pin 3 of the driver board?
Email me if you don't have the diagram I noted.
All J108s have 0.43V on the gates, they are not being turned-off so the signal is grounded out. I am measuring .0055 on the diode drop between D/S on all 4 of those transistors.
To answer your question, no there is no audio on Pin 3. However, theres audio coming out of the op-amps.
To answer your question, no there is no audio on Pin 3. However, theres audio coming out of the op-amps.
so far the 4N25 opto-isolator is not turned on, the LED is in-fact reverse biased at -0.8V.
I need to find out why this is occuring.
I need to find out why this is occuring.
I will give that a shot. I tried to chase the muting circuit, and it differs quite significantly from the example schematics unfortunately.
I jumped the opto isolator, and LED switched to green, both channels work and sound fine. no excessive current draw.
So something is up in the muting circuit somewhere
So something is up in the muting circuit somewhere
No, thats where it differs. For example, the transistor is on the bottom side of the opto instead of the top side, as an example. also the output side of the opto isnt push-pull. But that side is working properly anyways when jumped.
Also attempting to chase the chain back further, its radically different. For example, there is no diode OR-gate pair as indicated in the schematic. There are diodes but none that connect together like that.
So theres enough differences that render this version of the schematic inop
So theres enough differences that render this version of the schematic inop