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The epson projector suddenly balcked out. I've checked it form the power module and found that the main fuse of the primary power module which starts from the mains power. After replacing the blown fuse to a new one and turn on the projector then it goes down to the "no signal at all, no led's on" also found the fuse has been blown again. How can I locate faulty module/device to solve this problem ?
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It is likely a bad diode in the power supply.
Disassemble it and check the power diodes with an ohmmeter.
The problem may also be regulators or transistors after the power supply.
Many of those can also be checked with an ohmmeter.
Basically, something is shorted out and putting too much load on the fuse.
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Hi bill, Thank you for your kind comments. I also knew that the trouble would be in the short(s) in the circuits. The power system of the captioned projector model is consisted of three power modules i.e. first inlet power safety module where fuse, capacitors and inductors and a surge protection device which I don't know enough. And the second module is considered as main power supply which generate several output voltages for the main pcb and the adjacent balast power module. So it was very hard to locate the faulty device among these three modules. I have to check all three modules when the ordered spare fuses are in my hand. By the way is there any good method to isolate faulty module easily ? : )
I think this is the service manual for your projector.
https://www.nodevice.com/service-manuals...
Finding the part will involve an ohmmeter and some educated probing.
You can disconnect the modules and power them in sequence to find the bad one, but that will just eat fuses. Then you still haven't found the component.
As I said, it is likely a semiconductor device - diode, transistor, MOSFET, whatever. They are usually easy to locate with an ohmmeter. One that has a diode function helps. You are looking for a power device. Any small glass diodes or small transistors will probably not cause your issue.
There are none of those parts on the filter board that I see, so that eliminates that board. The black devices might blow a fuse but if they were bad, they would be visually obvious. They explode.
Unfortunately, the service manual has no schematics, so I can't point to particular devices.
I finally settled the problem and the projector is re-working at the loof of my house basement. The faulty devices were diodes of which I have changed three diodes one was the power diode and aother two are general purpose rectifiers.
Your suggestions were very helpful for my job and I appreciate your deep knowledge in the necessary field.
Disassembly and reassembly were not easy game to do it again, however, I have enjoyed it.
Cheers !
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