Onkyo TX-SV717Pro will not come out of standby.
in [Repair]
|
From: Mark Zacharias on 4 Feb 2010 21:27 "Gary L. Woodruff" <woodruffrepair(a)frontiernet.net> wrote in message news:pzDan.89480$1m3.54971(a)newsfe11.iad... > There is no relays clicking and no burnt components or even darkened areas > on any pcb. Ive got +13v going out from the pc but nothing coming back on > the power line(labeled on ps connector). I found q706 to be bad and > replaced it. I get vdd of 2.34vdc into q701 (microprocessor). I also see > 5vdc from the power switch shorting to gnd when activated. I do not see > anything coming out of the pin labeled power. I am thinking either the IC > should have a greater vdd or the chip is bad? > > Thanks for any and all help > Gary > > > > Gary L. Woodruff wrote: >> I have a Onkyo TX-SV717Pro that will not come out of standby. PS is >> sending 13v out. i have checked the output transistors and they are good. >> does anyone know of a common problem for these amps? >> >> Any and all help is greatly appreciated. >> >> Gary I can just about guarantee you've missed a large burned area hiding under the big white flat cable which goes from the main board up to the front panel. In this area are several resistors which have been overheated - any one or more could be open. Also there is a common tendency to develop cracks in the board there which actually damage the foil runs causing (again) open circuits. In extreme examples a hole may even be burned in the board. Look under that big white flat wire... I have a PDF of the TX-SV525 which is very similar in this area if you need it. Mark Z.
From: Gary L. Woodruff on 8 Feb 2010 14:35
Mark, Thanks for the tip. I do see the resistors you are speaking of r921, r922, r923 all .47 ohm 1/4 watt. All are good as well as the small rectifier diodes in the same area. There is some slight darkening of the pc board in this area but it is VERY slight. I do not see any voltage on the microprocessor pin labeled POWER when the power button is depressed. This voltage turns on a trans in the power supply feeding ac to the transformers. Shouldn't I at least see some voltage on this pin of the microprocessor? Thanks, Gary Mark Zacharias wrote: > "Gary L. Woodruff" <woodruffrepair(a)frontiernet.net> wrote in message > news:pzDan.89480$1m3.54971(a)newsfe11.iad... >> There is no relays clicking and no burnt components or even darkened >> areas on any pcb. Ive got +13v going out from the pc but nothing >> coming back on the power line(labeled on ps connector). I found q706 >> to be bad and replaced it. I get vdd of 2.34vdc into q701 >> (microprocessor). I also see 5vdc from the power switch shorting to >> gnd when activated. I do not see anything coming out of the pin >> labeled power. I am thinking either the IC should have a greater vdd >> or the chip is bad? >> >> Thanks for any and all help >> Gary >> >> >> >> Gary L. Woodruff wrote: >>> I have a Onkyo TX-SV717Pro that will not come out of standby. PS is >>> sending 13v out. i have checked the output transistors and they are >>> good. does anyone know of a common problem for these amps? >>> >>> Any and all help is greatly appreciated. >>> >>> Gary > > > I can just about guarantee you've missed a large burned area hiding > under the big white flat cable which goes from the main board up to the > front panel. > In this area are several resistors which have been overheated - any one > or more could be open. > Also there is a common tendency to develop cracks in the board there > which actually damage the foil runs causing (again) open circuits. > In extreme examples a hole may even be burned in the board. > > Look under that big white flat wire... > > I have a PDF of the TX-SV525 which is very similar in this area if you > need it. > > Mark Z. |