Earthquake PH10000D

[luigidedom]

is it possible that these amps have problems with the power supply driver transformer?

 

[luigidedom]

amp came in with a dead power supply, found the 494 wasn't oscillating, replaced the 494 and when turned on it killed the remote turn on transistor. replaced the transistor, removed the 2 driver transitors, the 494 oscillates normally.
refit 2 driver transistors and it heats the remote turn on transistor very quickly and 494 does not oscillate.

 

[Perry Babin]

Is the reason that the 494 doesn't oscillate because the voltage is dropping too low for it to operate?

 

[luigidedom]

When i fit the 2 driver transitors the remote turn on transitor gets extremely hot, the 494 was dead when the amp came in. I replaced the 494, the remote turn on transistor and the 2 drivers were both fine, but now when i turn the amp on the remote turn on transistor heats up rapidly, if i remove the 2 driver transistors the remote turn on transistor stays cool and the 494 osscillates as normal

 

[luigidedom]

Almost as if there were something drawing heavily on the 494

 

[Perry Babin]

The remote transistor delivers power to the driver transformer and the 494. If the driver transformer has a problem, that could cause the voltage drop.

 

[luigidedom]

Is it possible that the driver transformer can go faulty?

 

[Perry Babin]

Yes. They can fail but it's rare.

 

[luigidedom]

so ive replaced the driver transformer and the 2 driver transistors along with the remote transistor and 494, turn on and i still have the same problem with no power and the remote transistor heating up rapidly, i just cant seem to locate the source of this problem

 

[luigidedom]

anyone?

 

[rrae]

After replacing all mentioned, whats the problem?
Amp is not powering on? Is it powering on but transistor is heating up?

 

[luigidedom]

The remote turn on transistor heats up rapidly, like there is something loading the driver transformer

 

[Perry Babin]

Are you getting pulses from the 494?

 

[luigidedom]

The 494 pulses normally until i fit the 2 driver transistors then the remote transistor heats up and no pulses from 494 obviously as it gets no power to it
Still like there is something pulling power down when drivers are fitted

 

[Perry Babin]

Was the driver transformer the original or is it possible that someone replaced it with the wrong one?

Where did you get the replacement transformer?

 

[luigidedom]

The transformer was original i got a replacement from another 10000d
All windings on both transformers measure 3.7mH

 

[Perry Babin]

I would suggest pulling the transformer and reestablishing the connections on the 494 side with wires. For the secondary windings, connect the two pads for each winding with a resistor or jumper. This will ensure that the FET gates won't float and cause the PS FETs to conduct. Do you still have excessive heating of the remote transistor?

 

[luigidedom]

with driver transformer removed 494 does not oscillate, with driver transformer and driver transistors removed 494 oscillates

 

[Perry Babin]

1/2 of the driver transformer would be in the circuit.

 

[luigidedom]

if i have all components in place with the power fets removed i have no oscillation from 494, if i remove the c3206 drivers and the driver transformer the 494 oscillates on pin 9 and 10