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ITPeter, Engineer
Category: Home Theater-Stereo
Satisfied Customers: 18098
Experience:  Electronic Engineer
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HiI have Yamaha RX-V640. I never used rear center amplifier, but is bu

Customer Question

I have Yamaha RX-V640. I never used rear center amplifier, but is burnt up. I have repaired this amplifier. But one effect left.Amplifier not powering up. When pressing power on power relay make short click display short blink and power off. when I pressin this power on button three times amplifier powering on and working fine. Where is the problem?
Submitted: 2 years ago.
Category: Home Theater-Stereo
Customer: replied 2 years ago.
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Expert:  ITPeter replied 2 years ago.
Hi there,
This problem is somewhere in the amplifier's power supply circuitry.
Perhaps a component is shorted or has burned out.
Finding the problem component will be difficult and will require electronic testing if it is not visually obvious.
The most likely components to fail are the electrolytic capacitors.
You will need schematics and replacement components, along with the relevant reworking tools.
Also ensure to check for any poorly soldered joints and touch up if required - cracked or dry solder joints can result in this problem occurring.