Based om your description, do a measurement on the 4 TP1 points and post back.(make sure that you are referenced to a good ground).
You mentioned |
|02-11-2014||Bush 2878NTXSIL 28" Nicam Digital Television - Silver||problem whith sound : when I start the tv . the tv sound is tall this sound (zzzzrrrrrrr ) plzplz help me|
|03-11-2014||Need to filter it whith some (bbbeeezzz).|
|03-11-2014||Sony oem camera module fcb-ix47p||Has anybody have the service/repair manual for this camera module? I would be grateful if you can email it to me...... boswellrov2hotmail.com|
|03-11-2014||DENON AVR 2802 pROBLEMS(NO SOUND)||Hi
My Denon 2802 has just exhibited the exact problems Ramesh has described. Did a solution/answer to this get discovered?
|03-11-2014||panasonic tx-l32c20e chassis:GLP25||I NEED THE SERVICE MANUAL FOR PANASONIC TX-L32C20E CHASSIS:GLP25. PLEASE, TELL ME WHERE I CAN GET THE INFORMATION|
|04-11-2014||Harman Kardon AVR 7500 Front right channel problem||I have this very nice Harman Kardon AVR 7500 Surround reciever.
But right now it's not so great.
My right front channel had been acting up a bit lately, with a heavy crackling sound when powered on. Only the right front channel though.
It could play |
|04-11-2014||THANK YOU VERY MUCH|
|04-11-2014||Yamaha RX-V659||In this model the problem was the capacitor C654 22nf 650V|
|05-11-2014||This is the sound that comes out of my front right speaker, when attached to the reciever. I cannot figure out what the trouble is. Other than I believe it's the front right amplifier that has a problem. Possible a MOSFET that is bad. But I have no way of|
|05-11-2014||Does noise continue if "pre" is isolated (unplugged) from "main?"|
|05-11-2014||i want to by a dalvi decoder dsr400. can someone tell me where i find one?????????|
|05-11-2014||No, then the sound dissapears.|
|05-11-2014||No when the pre outs are unplugged the noise dissapears.|
|05-11-2014||a) Get an external audio amplifier with its own speaker. Plug its input into the right front "preout" jack and see if noise is present.
b) Take the output of a external preamp with an audio source connected and playing hooked to it |
|05-11-2014||Ol, did a test. Used the right channel preout and connected it to the left channel inppu. The noise moved from the right to the left, so the problem is definetly before the amps them selves.
So I would think the problem is in the DSP board then.|
|05-11-2014||My manual says 'preamp' in exploded views and 'processor' in schematics.|
|05-11-2014||Ok. So if it's the preamp, I'm thinking it would probably be something like a capacitor that was the problem.
Do you have the entire service and repair manual for the AVR 7500??|
|05-11-2014||Strange that ONLY one of the five channels is affected. Cap or a bad joint or a switching IC (but only one portion?) or a noisy op amp (but only one portion?).
|05-11-2014||I can't download them. I failed the registration attempt, so I have to wait a few days.|
|05-11-2014||After clicking on your choice of link...
Scroll to bottom (below "Document Preview" pane);
The line: "This file is downloadable free of charge... processing (please wait)"
will change to: "This file is downloadable free of c|
|05-11-2014||Cool, that worked...
Now I just have to find heads and tails of the service manual. :)|
Thanks for getting back...Anyway, I think I made it worse when I installed a new amplifier chip since we last spoke. The readings are not anything close to what they were (from the amp chip). All most all of them are either 65 or -65. Here ar|
|06-11-2014||Lets hope your new chip is not counterfeit? At this point, I still think your original IC is probably still ok?
HOWEVER, after posting your readings for the plus/minus 16 volt, there is definitely something wrong there. The plus/minus16 volts are used as|
|06-11-2014||Must admit that my trouble shooting skills aren't what they used to be.
I'm struggling to find heads and tails in this.
Only thing I know is that it's not the amplifier itself that fails. It's somewhere between the pream and the volume control I thi|
|07-11-2014||You'll need to create your own places to divide the circuit. Today's surface mount parts and double-sided or multiple layered PC boards do not make this easy. Looking at the block diagram is easier, but finding a convenient point in the circuit to electri|
|07-11-2014||I will do a check of the headphone jack. If no noise there I'm pretty sure the problem is with IC716 as you say. I have looked over the entire block diagram, and as you say IC716 is the one that could be the trouble maker, and or the surrounding parts. Mo|