Using the regulators ground and measuring at opamps I get +- 15 volts at opamps .
Amp powers up and produces all the correct voltages but the protection led is lit and not the power led
Amp powers up and produces all the correct voltages but the protection led is lit and not the power led
I’m going through this amp top to bottom .
Is it normal to get a square wave on the drain (middle leg) of the power supply fets ? IRFP064N
Is it normal to get a square wave on the drain (middle leg) of the power supply fets ? IRFP064N
Back to this amp .
If I place black probe on ground terminal of amp and red probe on rca shield ground I get -12 volts
From ground terminal to rca shield ground I het no reading when set to ohms .
If I can plug the rca jacks in the amp will not power up it stays in protection mode and the clip light also is lit .
Any ideas ?
If I place black probe on ground terminal of amp and red probe on rca shield ground I get -12 volts
From ground terminal to rca shield ground I het no reading when set to ohms .
If I can plug the rca jacks in the amp will not power up it stays in protection mode and the clip light also is lit .
Any ideas ?
Attachments
What's the difference in these two tests?
If I place black probe on ground terminal of amp and red probe on rca shield ground I get -12 volts
From ground terminal to rca shield ground I het no reading when set to ohms .
If I place black probe on ground terminal of amp and red probe on rca shield ground I get -12 volts
From ground terminal to rca shield ground I het no reading when set to ohms .
Not sure
If I place the black probe on amps ground terminal and red probe on rca shield ground the meter just keeps flashing like it wants to read but can’t get a reading .
The rca ground shields go to this opto coupler .
Is there a way to tell if it’s bad ?
If I place the black probe on amps ground terminal and red probe on rca shield ground the meter just keeps flashing like it wants to read but can’t get a reading .
The rca ground shields go to this opto coupler .
Is there a way to tell if it’s bad ?
Attachments
Still won’t read from ground terminal to rca shield ground .
If I remove the optocoupler then I bet 0.00 ohms between shield ground and main ground .
If I remove the optocoupler then I bet 0.00 ohms between shield ground and main ground .
I dont get any deflection of the trace .
The amp will power up if no rcas are plugged in
If I plug the rcas in the amp stays in protection mode and the clip light is also on
The amp will power up if no rcas are plugged in
If I plug the rcas in the amp stays in protection mode and the clip light is also on
I guess I didn’t check them again until now .
The cap and resistor are burnt again.
I will replace them and see what I come up with
The cap and resistor are burnt again.
I will replace them and see what I come up with
I guess I’m gonna have to go through this entire amp .
I replaced the 1K resistor and the 0.1uf cap
The power protection and clip lights are on
I replaced the 1K resistor and the 0.1uf cap
The power protection and clip lights are on
It burnt the cap again .
But when I measured it it dropped from -12 volts to -4.69 volts .
I will go through the circuit and see if I can find the issue
But when I measured it it dropped from -12 volts to -4.69 volts .
I will go through the circuit and see if I can find the issue
Twisting the transformer has no effect .
I used a 1k resistor for the RGND location and it dropped the voltage down to 4 volts .
I’m not 100% sure the value is correct .
Can I lower the value of the resistor to see if that changes anything and if so what value would you recommend
I used a 1k resistor for the RGND location and it dropped the voltage down to 4 volts .
I’m not 100% sure the value is correct .
Can I lower the value of the resistor to see if that changes anything and if so what value would you recommend
You can lower the value but I don't think it's going to help. There shouldn't be anything pulling the secondary down.
Are any of the op-amps getting hot?
Are any of the op-amps getting hot?