The voltage on the terminals connected to the rail caps alternate but, under normal operating conditions, they alternate at approximately 80,000Hz.
Although it's possible that one of the transformers was damaged, it's unlikely. You can check continuity between pins to see if one of the windings is open. A more likely fault is a defective driver transistor or an out of tolerance resistor in the drive circuit.
Although it's possible that one of the transformers was damaged, it's unlikely. You can check continuity between pins to see if one of the windings is open. A more likely fault is a defective driver transistor or an out of tolerance resistor in the drive circuit.
Perry,
I have replaced most of the components of both drive circuits. Keep in mind that I have not installed the irfp260n fets yet. I removed the bank that was not getting power. If I diode check the bank that was operating properly I get. The two outer holes on circuit board I get ~.568 and reversed .625 . On the bank that is not powering up I get .928 and reversed it acts as it is charging up kinda quick until I read OL.
I have replaced most of the components of both drive circuits. Keep in mind that I have not installed the irfp260n fets yet. I removed the bank that was not getting power. If I diode check the bank that was operating properly I get. The two outer holes on circuit board I get ~.568 and reversed .625 . On the bank that is not powering up I get .928 and reversed it acts as it is charging up kinda quick until I read OL.
Perry,
i have replaced all of the ES2D diodes and AO6 and A56 transistors for the drive circuits. I also replaced the 100, 200, 10, and 0/jumper resistors for the drive circuits. still no luck, i hope was hoping to find a open resistor or shorted transistor somewhere. I am still reading 0.942v on diode check across the two outer holes for one direction and then reversing the leads to quickly watch the reading increase until it reads OL. I have printer here at work large enough to print out a 2ftx3ft schematic so i can notate the readings. could there be a short or fault outside the driver circuit in parallel giving the false readings i am getting?
i have replaced all of the ES2D diodes and AO6 and A56 transistors for the drive circuits. I also replaced the 100, 200, 10, and 0/jumper resistors for the drive circuits. still no luck, i hope was hoping to find a open resistor or shorted transistor somewhere. I am still reading 0.942v on diode check across the two outer holes for one direction and then reversing the leads to quickly watch the reading increase until it reads OL. I have printer here at work large enough to print out a 2ftx3ft schematic so i can notate the readings. could there be a short or fault outside the driver circuit in parallel giving the false readings i am getting?
All of the FETS are removed from the PCB board. shouldn't all the output positions read for the 4 banks read identical? or do you think since they are constantly switching on/of that 2 banks will read differently?
Originally, i replaced the blown FETS and the unit would power and play sound but would distort when cranked up. So measured power to the FETS and discovered ~110 on 2 banks and about ~8-10 on the remaining banks.
Originally, i replaced the blown FETS and the unit would power and play sound but would distort when cranked up. So measured power to the FETS and discovered ~110 on 2 banks and about ~8-10 on the remaining banks.
remy tail;
Perry,
Sorry for the delay in getting back with you. Turns out after replacing the FETs and replacing all the components of the 4 drive circuits it powered up and played perfectly. Thanks for all your help...
Now, for the next one.. I have another T40001BD that someone else repaired and they're work is somewhat questionable. I first opened the unit up and diode check the outputs and the powersupply chips. Everything seems fine. So i powered up the amp and everything is fine. No protect light until about 10 seconds. Amp meter on powersupply is around 1-3 amps and then jumps to 10amps. Nervously, i power down and check for hotspots. Nothing obvious, I power up again and check output voltages. I read 110v on half the outputs and then the unit goes into protect. I remove power and remove the +hv, gnd, -hv from the output board and power up. Unit stays out of protect mode now but i seem to have higher voltages from the previous amp. I am reading 184v from +hv and -hv. Does this seem normal or high? I was expecting around 120 or 110V.
Perry,
Sorry for the delay in getting back with you. Turns out after replacing the FETs and replacing all the components of the 4 drive circuits it powered up and played perfectly. Thanks for all your help...
Now, for the next one.. I have another T40001BD that someone else repaired and they're work is somewhat questionable. I first opened the unit up and diode check the outputs and the powersupply chips. Everything seems fine. So i powered up the amp and everything is fine. No protect light until about 10 seconds. Amp meter on powersupply is around 1-3 amps and then jumps to 10amps. Nervously, i power down and check for hotspots. Nothing obvious, I power up again and check output voltages. I read 110v on half the outputs and then the unit goes into protect. I remove power and remove the +hv, gnd, -hv from the output board and power up. Unit stays out of protect mode now but i seem to have higher voltages from the previous amp. I am reading 184v from +hv and -hv. Does this seem normal or high? I was expecting around 120 or 110V.
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