I inherrited a Denon avr 4800 reciever that when powered up immediately shuts off and the red power led flashes rapidly, any ideas? Richard

Greetings
the red flashing LED is that the Device is in protection mode.
the internal power supply . +15 volts and -15 volts are defected you need to be replace it ... Regulators 7915 and 7815 .... these you should change , might also need to check capacitors .
these are common defects for Denon . AVR units.
Good Luck
Hope this helps

http://www.retrevo.com/support/Denon-AVR-4800-Receivers-manual/id/363ag816/t/2/

I'd treat this symptom as "DISPLAY not lit and power indicator is flashing rapidly." under Troubleshooting on Page 60.

and I'd evaluate the speaker load you're presenting to make sure it's effectively higher than 6-0hms per speaker channel.

replace all the electrolytic capacitors in the power supply. i had the exact same problem with mine and once i replaced the capacitors it powered up and stayed on and worked perfect.
these capacitors tend to fail as they're of poor quality.
this fault is very common on denon receivers, especially the later models.

hope this helps?

maybe your system has an overload protection circuits that automatically shuts it off when too much volume is detected.

If it's cool and the vent holes are not blocked, probably.

The unit more than likely has a fault in the power supply or the output stage. Common switching power supply problems are the FETs used for switching fail or the PWM generator fails. Output circuits can be configured many different ways. The trend these days is to use integrated high power amplifiers for each channel instead of discrete push pull amplifier stages.

Internal problem with power supply or one of the channels. Bring it to a repair facility.

Hi, this is a power board issue. remove the cover and make sure that this unit doesn't have blow fuse. if the fuse is fine, you will then need to replace the integrated power/ main board.

this could be two wires touching on the back connections. one wire touching another ...just one will do this! look close and causing a short (its shutting off is a safety feature so the unit does not overheat)

hello my friend denon receivers are famous for the power problem, check all the connections first and if there is not solution your power supply has a problem

good luck


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