Hi guys i have a sony receiver where the rear right channel is not working, all other channels r working, speakers all good switched them around to check ,still rt channel ng nothing comming out of speaker any advise?
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For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.
Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic. -
Re: Sony STR-DE725
With Plain Bill's service manual schematic in hand, start with the defective side's speaker terminal, and work your way back. I didn't check the PDF, but some units do have output fuses (rare these days) so be on the lookout for that. If there are discrete (transistor/MOSFET) output devices, you can check them for shorts (collector to emitter). Also look for signs of overheating near the big heatsink...even if the insulating washers are distorted, or the board under the device is browned you may have found the problemComment
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Re: Sony STR-DE725
Check the output transistor, Q757 on page 21 of the schematic, for a dead short (zero ohms) with your multimeter. You can check it incircuit if you have a DMM, or remove it to be sure. This appears to be the output section for the rear (surround) portion of the audio amp. It appears that the protection relay circuit protects both left and right with the same DPDT relay, so if you hear sound from the left, its probably not the protection circuit.Comment
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Re: Sony STR-DE725
Since the left channel is a mirror of the right, compare the collector to emitter resistance of Q757 to Q707. If the transistor is shorted, you should see nearly zero ohms on Q757.Comment
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Ok start off by saying I have some tv repair but not much on the receiver end.
Picked up a Sony str-dn850 home receiver when I first plugged it in powered it up it came on and the system check relay clicked and about 3 seconds later it went into protection mode.
I powered it off and on. Comes on no problem.
Hooked up speakers and it started to pop and crackle but the volume was all the way down.. and I was only getting that sound out of the left channel. Right channel had no sound.. but every time I turn the volume up it has a smell crackling sound on ever volume number...... -
Anyone run memory speed tests with an old X58-based triple channel 1st gen or any other >2 channel board? The one I have is a Gigabyte I think.
Anyway I had four 4GB DDR3-1333 modules in the 6 memory slots and got around 11GB/sec memory speeds assuming that it went dual channel since it didn't have enough modules for triple channel. Now I stuck in two more 4GB modules, but they are DDR3-1600. I'm still getting 11GB/sec speeds according to memtest86...
Just wondering, anyone do memory speed analysis on these triple (and higher) channel memory boards? Are there any... -
Hey fellow solder fume lovers, I have a Vintage Sony Receiver STR-4800 SD that has me stumped.
The Balance Pot has to be set at about 30 degrees (11 o'clock) to the left for the output to be balanced (see photo). I'm using an oscope, sig gen 1kHz sine, 8 ohm dummy load).
When output is balanced (11 o'clock left) both channels clip at about 19 vac / 45 watts RMS, Amp is rated at 35 watts so I know the amp modules are good. Square wave also looks good when turning bass & treble pots and is in phase.
I pulled the balance pot, (Dual 10K MN Taper) cleaned with... -
Hi friends
I have reverse engineered this tester, schematic is attached and is complete except for capacitor values. These testers annoyingly have no model number but they are the ones you find on the first page of just about any website if you type in "18650 4-channel tester". There is also a 2-channel variant and a newer 8-channel variant. They are very cheap (about £15) and can measure voltage, current, internal resistance and capacity. They have a multicolour display for all these statistics. They also have terminal blocks so that if you want to use a breakout board... -
My 7 channel NAD receiver has audio quality and volume issues on 2 of the channels. Sometimes they work and sometimes they don't. Sometimes they're at about half the dB level of the left channels, and then they cut out entirely. Powering off and on the receiver fixes it for a bit.
Without much experience to really know for certain, they only apparent issue I can see is with these electrolytic capacitors on the power supply. Bulging = bad, correct? I'm looking for replacements but I'm unsure what leeway I have with the temp ratings. Are there any other specifications I need to worry...
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