Wierd Audio Output From Stereo

[musthave]

hamdiya get your self a can of compress air the type used for computer cleaning and spray your master volume control and the bass, treble and balance and selector switches youre potentiometer are dirty spray them in the back .
I have a old sansui amp that does the same noise as yours and thats what i do to mine every 6 month dust gets in the controls even the push button selector its a pain but it works real good after that .

 

[poopeater]

Im willing to buy anything to fix it.

Thanks

How about you buy a new camera or a tripod and take some pictures that don't suck ass? Sheesh, how could you even think that posting those blurry, terrible pictures was even a good idea? We can't see anything in those crappy pics. Did you not even look at them before posting them?

 

[HiTech]

hamdiya get your self a can of compress air the type used for computer cleaning and spray your master volume control and the bass, treble and balance and selector switches youre potentiometer are dirty spray them in the back .
I have a old sansui amp that does the same noise as yours and thats what i do to mine every 6 month dust gets in the controls even the push button selector its a pain but it works real good after that .

That's a band aid fix if you ask me. Much better off using a quality contact cleaner in a spray can, like DeOx-it. Once done, the item works from that point on without issues. Compressed air only forces the dust elsewhere and does absolutely nothing to promote good electrical contact by controlling oxidation.

 

[hamdiya]

How about you buy a new camera or a tripod and take some pictures that don't suck ass? Sheesh, how could you even think that posting those blurry, terrible pictures was even a good idea? We can't see anything in those crappy pics. Did you not even look at them before posting them?

I'm only human...

In response, i've taken and posted new photos(Goto Page1). Descriptions will explain them.

PS: i can't use an air can simply because there is no where to apply it. The volume control is sheilded with this plastic cover. I doubt any dust would have entered there...could it?

Something to keep in mind, when i just turn on the stereo, i can get proper audio output, but a few seconds later, it starts (the speakers i.e.) making that noise. I know i mentioned this before, but i didn't get any feedback on that. Any explanation for this?

 

[HiTech]

OK, listen up! Since it's obvious to me that you lack the servicing expertise to safely service this thing (not slamming you), it's best to have it serviced by a REPUTABLE Sony service ctr. I suspect a solid state device to be failing as it warms up after the first few seconds. A component may have gone "thermal" and that static noise you provided in your first post does mimic a noisy transistor or similar active component. Now you could go and buy a can of Freeze Mist or similar cold spray, and spray it on the active power supply components, etc. to see if it disappears or worsens to better locate the suspect part(s). Then again, if you can't even identify basic electronic components in a stereo amp, don't waste your time nor money with further experimenting.

 

[hamdiya]

Like i said, ill hopefully take it to a Sony service center on the weekend.

 

[tunedwolf]

that stk driver module would be a favourite suspect in my book...but unless you have a scope and a signal generator, I would say let the guys at the local service centre look at it...

 

[hamdiya]

Today i finally had the time to take it to a sony service centre. To my surprise, the guy told me repair could be about $150! Seeing as i can get a brand new stereo for about $175, it seemed hardly worth it.

He did tell me this could be an Audio IC problem. Thought to my self, why not spend $50 on IC's and relpace most of em, seeing as i am electronic hobbiest and have experience with soldering, this would save me quite a handfull of pocket money. Any suggestions on which IC could be @ fault here?

I just thought of something today. A few months ago, a computer that i had, began to restart randomly and acting all funny. Took it to a service center, replaced the VGA card, but the problem returned very shortly after. This got me to think, perhaps Humidity/Heat (which is very high in my country) has affected some components and the same has happened to my stereo. Question, are there any components sensative to heat, or humidity in particular?

 

[bigkim100]

He did tell me this could be an Audio IC problem. Thought to my self, why not spend $50 on IC's and relpace most of em, seeing as i am electronic hobbiest and have experience with soldering, this would save me quite a handfull of pocket money. Any suggestions on which IC could be @ fault here?


Im not going to waste much more energy on this...and I suggest that you do the same.
Saying that the problem is a IC, is like taking your car in for service...and them tellling you that its a problem with a pesky screw. Cant blame 'em though....I wouldnt tell you the EXACT problem either, and my response to a person that brings in something for a quote, is that its a "IC problem"....even if its a problem with the Electrolytic caps in the power supply. No sense giving away a diagnostic finding for free (dont bother telling me what a stinker I am, I am quite well aware that MOST customers are like this guy, wanting me to do all the difficult diagnostic work for free...then go out and buys el cheapo parts, and replaces them himself). Quite frankly 99% of the people dont know the difference between a IC and a Electrolytic anyways.
I doubt that you will be able to replace every ic in the unit, for the price you have stated.....and since its a audio processor....all the ics in there are technically "audio ICs"....again, if its truly a ic problem. I would think that it may well be the caps in the power supply, as stated by another poster, earlier.
Quite frankly, without proper test equipment to narrow it down...you will just be pissing in the dark.

With that negativity being said...I think that your idea of actually posting a audio file of the sound of the problem was quite a good idea...one that usually is not used by even experienced posters.
Overall your questions were quite logical, even if your pictures wernt particularly useful.
Unfortunatly...with the advent of EBAY...ts just another nail in the coffin of repair shops, since at any given time ANY piece of electronics is available, for a tiny portion of its original price, and a even smaller portion of a repair cost.

And by the way....I PERSONALLY think that the repair cost that they quoted was a pretty good, and quite fair.

 

[fingaz]

well,

The first thing's i'd look for are any loose wires or "dry" solder joints.
you can tell dry solder joints by their appearance, they usually look dull.
If you can get if to work for a while, then maybe something is overheating (a transistor not heat-sinked properly??)

 

[fingaz]

oh, just a thought. . . you could try checking the wiring in the mains plug. . . I've known stranger things. . . loose or damaged wires on mains cable can cause RFI. which would be heard as a clicking or crackling sound.

 

[hamdiya]

I'll try to take a look asap. Right now i have exams, bah! Wish me luck

 

[HiTech]

I see I'm back once again!!!

Other than your claimed soldering skills I wouldn't endeavor beyond that of touching up any suspect connections. If you can't even identify electronic components then surely troubleshooting them is out of the question. Don't waste time & money experimenting with guesses on your behalf or the repair tech's!! Without him probing under the cover, all he can do is take an educated guess, that is unless he happens to know of this to be a specific and common problem with that model unit. Once again, having the unit on my bench infront of me with test meter and other aids, is EVERYTHING! Other than that it's speculation and guesses. You have two choices:
1. inspect for the obvious like poor solder joints and loose wires; if problem still persists, then have it professionally serviced.
2. scrap the damn thing, and buy a replacement off of eBay or something newer in a store!

C'mon man, the writing is on the wall.... read and comprehend. I admire your determination to try and fix the thing, but you need to realize when your up against all odds from lack of specific skills, and either need to turn to professional help or go the other route of replacement.

 

[fingaz]

hey, what's the prblem? most of us learn by experimenting. . . the guy's got nothing to lose by looking, and trying to fix it.

if all everyone can suggest is to throw it anyway, then where's the harm in it?
and if he gets it working, then he's saved some money and learnt something in the process

I don't understand why everyone has to be so negative :-(

 

[n.house]

Right, this could be easy, check for dry joints and then spray with WD40, That should do it.

 

[Blueteeth]

hey, what's the prblem? most of us learn by experimenting. . . the guy's got nothing to lose by looking, and trying to fix it.

if all everyone can suggest is to throw it anyway, then where's the harm in it?
and if he gets it working, then he's saved some money and learnt something in the process

I don't understand why everyone has to be so negative :-(

Totally agree. I swear most topics could be shrunk significantly if everyone posted 'useful' information. This is a place of learning and sharing opinions, of course its down to the moderator to moderate, but still, little jokes and snide remarks get people nowhere, except extra 'posts' and damaged credibility.

*gets off high horse*

As for the problem? I really don't have a clue. I'd inspect the mian board for dodgy solder joints as already suggested, then all the cables. In my experience, 9/10 its a mechanical failure..ie, pots, switches and connectors/cables....always check your cables and connectors . You could also power it up feel any power transistors/mosfet's for excessive heat (a sign of a bust component) although with any mains in there, might be a bit dangerous. Can you see ANY discolouration around components? I've had diodes blow on me before, shorting and then causing a cascade of other shorts...all visible on the PCB as nasty scorch marks. After all that, test the electrolytic caps, signs of leakage etc.. I doubt if any IC's have gone, al least not without some protection components giving up the ghost, and then you probably wouldn't get any output at all.

Thats how I debug things anyway, connectors, switches, pots, semi's, diodes, and caps. Also, staring at it for about 10-15 minutes almost always provides new inspiration as to where the problem lies...or is that just me? If all that fails, try and get hold of an oscilloscope and probe like its going out of fashion.

Someone did bring up the 'just replace it' idea, which, if much repair time /components is require, is always an option, but that would defeat the point of your post, so I guess you're up for the challenge. Good luck sir

Blueteeth

 

[tunedwolf]

I thought I had posted something useful...no snide remarks either...
My money is still on the stk driver module...

 

[Nigel Goodwin]

I thought I had posted something useful...no snide remarks either...
My money is still on the stk driver module...

It's certainly a common problem, and many of them are no longer available