Post the voltage on all terminals of the 494. You can use a right-angle probe to get to the terminals without removing the board.
Pin 1:6.53
Pin 2:2.54
Pin 3:4.64
Pin 4:3.96
Pin 5:1.53
Pin 6:3.52
Pin 7:0.00
Pin 8:14.64
Pin 9:0.00
Pin 10:0.00
Pin 11:13.64
Pin 12:13.64
Pin 13:4.96
Pin 14:4.96
Pin 15:4.96
Pin 16:0.00
Pin 2:2.54
Pin 3:4.64
Pin 4:3.96
Pin 5:1.53
Pin 6:3.52
Pin 7:0.00
Pin 8:14.64
Pin 9:0.00
Pin 10:0.00
Pin 11:13.64
Pin 12:13.64
Pin 13:4.96
Pin 14:4.96
Pin 15:4.96
Pin 16:0.00
Pin 1 is too high. It's likely driven by the comparator. You need to determine which input to the protection circuit is causing the amp to be in protect.
Something on the audio driver board is causing the amp to protect so I pulled it out .
Once I load the power supply drivers all drive signal goes away .
Here is what I get with a 0.1 cap between gate and source for the power supply fets . Scope set to 5us 5 volts/div
Any ideas why I lose all drive signal once I load it
Once I load the power supply drivers all drive signal goes away .
Here is what I get with a 0.1 cap between gate and source for the power supply fets . Scope set to 5us 5 volts/div
Any ideas why I lose all drive signal once I load it
Attachments
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This amp appears to use an emitter follower pair so the diodes (if connected between the base and emitter of the PNP driver) are likely 10v Zeners. Did you pull one to look at the number?
Replaced the drivers again and made sure I had good connections from the top to bottom of board . I get the same waveform on all 4 banks
Scope settings are 5us 5volts/div. with a 0.1uf cap
Do these appear to look good or domination have an issue ?
Scope settings are 5us 5volts/div. with a 0.1uf cap
Do these appear to look good or domination have an issue ?
Attachments
Power supply is up and working .
If I put the audio driverboard in the amp it protects I’ve tried 2 different driverboards in the amp 2 that was brand new and have the same issue .
I notice that when I power the amp up I have 0 volts across the speaker terminals as soon as I remove the remote wire the voltage goes up to about half of a volt .
Any ideas on what to check ?
If I put the audio driverboard in the amp it protects I’ve tried 2 different driverboards in the amp 2 that was brand new and have the same issue .
I notice that when I power the amp up I have 0 volts across the speaker terminals as soon as I remove the remote wire the voltage goes up to about half of a volt .
Any ideas on what to check ?
Ok I did some more testing .
With just power and ground hooked up to the amp I bet 14 volts on the output filter inductors .
Is this normal or do I have a problem somewhere ? If I have a problem with voltage being on the inductors any ideas on what to check ?
With just power and ground hooked up to the amp I bet 14 volts on the output filter inductors .
Is this normal or do I have a problem somewhere ? If I have a problem with voltage being on the inductors any ideas on what to check ?