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Posted on Oct 26, 2009

I have a harman kardon avr 745....looks frozen

I have a harman kardon avr 745...when i last turned it on...all the display lights came on and the volume blue light is pulsating....i tried unplugging and a reset .....still does it....ps no sound thanks

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Pekka Jalomaa

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  • Posted on Dec 09, 2014
 Pekka Jalomaa
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My device is AVR 645, but AVR 745 has the same power regulator board and you could check, if the problem is there.
(AVR 645 volume blue light was not pulsating)
When device is turned on, it shows all display indicators,
no blue light on volume button and no response to any remote or front panel buttons.
Reason for failure:
No 3.3V and 5VD voltages.
I checked bridge rectifier D701 on power regulator board.
One of the diodes was shorted. Also fuse F702 was blown.
Original D701 is KBU6G, but because regulator board is a bit difficult to get out, I decided to use KBU8G. The only difference is Amps rating 6A versus 8A.
Be sure to use SR-5-3.15A fuse to replace F702 and use heat sink paste (you know where) when board is reinstalled.
There is large heatsink in the middle of the receiver. Power regulator board is mounted on the right side of that heatsink. It is down there near the front panel and to get it out you most probably first have
to remove two PCBs hindering access to some regulator component screws. Here are pictures to clarify situation:

I have a harman kardon avr 745....looks frozen - harman-kardon-avr-745-looks-frozen-igzigj2finjgh1nndvq1cugs-5-0.png

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  • Posted on Apr 23, 2010
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Did you happen to come up with a solution. I have the same problem, 100% as you have described it.

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