I've got a Sony CD player, model CD-P 750, which from one second to the next developed a loud static noise on one channel (and a tiny bit on the other) when playing a CD. Changing audio cables made no difference. No bulging caps or other "burnt-up" components visible. Any ideas anyone before I throw it out? Thanks.
Cracked solder joint? You shill could have a cap shorting, just not permanent.
Bad IC or semi.
Take a can of component cooler, it to make some noise and start freezing IC's, then caps etc..
Jamie
Gave the circuit board a good workout, and tried the component cooler, but no luck.
Broken down DA converter or its input data?? Try heating/cooling locally, to see if there is a broken solder connection somewhere. Bending the print in various places, to see if there are bad connections. Last resort, buy a new one.
"Bert"
** By static noises you mean the sound of heavy rain or surf - right ? ** Likely to be in the digital filter, DAC or audio circuits, since it is in one channel.Shame to toss well built gear like those old Sonys.
I still have a CDP101 ( bought new in 1983 ) in good working and cosmetic order.
.... Phil
If the problem is not the actual D/A converter, I would suspect the buffer transistor at the outputs. For this vintage of player, there sould be a couple of to-92 transistors just prior to the audio output jacks. Check/replace those.
Dan
The noise sounds like holding a small DC motor with bad brushes next to an AM radio.
There is an 8-wire ribbon cable going from the CD unit to the circuit board, close to a Sony 7M01/CXA1081 chip. When holding my finger near the cable, WITHOUT TOUCHING IT, the noise diminishes, and the audio/music starts to crackle and break up. Touching 4 of the insulated ribbon wires lightly will instantly stop the player.
When I ground my hand and THEN touch the same insulated wires, the noise stops also, but the audio - while continuing to play - becomes very distorted, and eventually stops as well.
"Bert = Troll "
** OK - your Sony is obviously possessed by demonic creatures form Hell.Or you are.
Take your pick.
.... Phil
I had more than a dozen Sony units from that era - a fabulous Trinitron TV, lots of high-end Beta and VHS VCRs, including a nice SLV-R5U SVHS VCR. Except for a rarely used Hi8 EV-S7000, they and that CD-P 750 player are all history now.
OTOH, I also still have a number of JVC units (high-end stereo, dual cassette, CD player...) from that same time period, and every single one still looks and functions like out of the box...
No troll. It's a factual description of the symptoms. You can check it out and play with it any time you like.
If it's still in working order, consider yourself lucky.
Yes, particularly since parts are likely not available any longer now - but what do you do with them, even when in perfectly working condition?
They were great for linear editing by providing a separate audio channel that could be edited without affecting the video, however while the EDIT switch was supposed to kill all on-screen text, you still ended up with some unwanted text on the finished video when pressing certain buttons while editing. Installing a small switch to shorten the on-screen dialog when editing fixed that.
Regardless, they still look very impressive just sitting there on the shelf taking up space...
With this sort of fault you can often zero in to where the fault is ,with a crystal earpiece connected between ground and a probing pin
?
board,
cable,
Offhand, i would say that you have put your finger right on the problem.
?-)
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