Everything on this amp works except the relay wont close to send output audio to the speaker terminals, the relay is control by the PWM card (one that has the gate drivers on card, not on amp board). B+ is on the relay coil from by default straight from B+ in, the card is used to control the GND to activate the relay, i really not seeing a fault so to speak on the card and the circuit traces are ok, is there any likely component to check? (the realy is good when i send GND to it, it activates).
Ive replaced Q4 and Q5, R5 is 270k read out of circuit. the relay is still not been provided with the GRN pulse. where is that pulse coming from? is it been driven from a signal path from the KA7500? what other method can use to drive the relay as im tired of the desoldering and resoldering the PWM card from the main board, even as little as to make measurments when install is complicated.
The attached diagram is basically the same circuit.
C3 could be defective if R5 isn't charging it but it's not a common failure.
C3 could be defective if R5 isn't charging it but it's not a common failure.
Absolutely correct Mr Babin, the C3 was infact defective, was almost 56uf from a 100uf value, i didnt have a surface mount to replace as factory but i bent legs and mount a thru hole as close as perfection allows. Amp is up and running again
Maybe, as these amps age, this will become more common. It doesn't take much internal leakage to prevent the 270k ohm resistor from charging the cap.
Good day!i have same problem with one hifonics bxi 3000d.I tried to measure transistor for relay but those transitors was covered with a ceramic paint.I removed paint and i distroyed transistor 3pcs.Now amplifier is dead and before was good without protection.i need that smd code for transistors or equivalent.!Attachments
Glad this was posted i had to pull C3 and found it to be defective in Zuess Zxx 2400. Saved me some time with this not so common fault.
Please tell me which diodes are placed here? Or does someone sell this driver, I really need it, my driver is in this condition
Please don't post in a repair thread that was started by someone else unless you are trying to help them.
Start a new thread if you need help with a repair of your own.
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Start a new thread if you need help with a repair of your own.
If you think this thread is relevant, include a link to it in the original post of your new thread.