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-   -   about maintenance of amplifiers (http://www.diyaudio.com/forums/solid-state/223560-about-maintenance-amplifiers.html)

aras84 14th November 2012 11:21 AM

about maintenance of amplifiers
 
Hi

Several days ago i bought a Sony TA-F 730 ES amplifier that has good sound quality, and so so clean
chassis. i checked the inputs, outputs, buttons on the front pannel everything seems correct. Mosfets are correct mosfets that org. Sony TA-F 730 ES. i didnt open the inside of the chassis when was buying it but have a check with torch nothing seems excepts lots of dusts. In saturday i want open the chassis and want to clean with air compressor for cleanin bords and the chassis inside itself. can you guys give me advise for using this device for long years to check what i must look for possible problems or problems that may couse bigger problems in the future. By the way does it needs a periodical maintenance and how can i do :D...

Mooly 14th November 2012 11:37 AM

All this depends on your abilities...

For basic cleaning a vacuum and soft brush usually suffices. Compressed air is OK if you have the correct gear but isn't my favoured approach.

Beyond that most PCB's and components can actually be washed to bring them up like new (foam cleaner followed by water) but this is where experience comes into play. Unless you can recognise the parts that may be harmed such as tuned circuits/coils/variable caps etc etc then the advice has to be don't.

Amps are maintenance free unless you have a specific issue to address and fix. Old well used amps can suffer from deterioration of electroylitic capacitors but its not such a problem as you may be led to believe.

aras84 15th November 2012 12:19 PM

Thank you so much for informations. If I see or believe something that may could cause a problem inside of amplifier will add a few photos...

overtheairbroadcast 15th November 2012 03:12 PM

I agree with Mooly, most don't need a wash. However with that said, I bought a nice Sansui B-1000 amplifier for $12 at the used charity store and it was likely owned by a smoker as you could just smell it after picking it up.

After some Windex, I could see the lettering and markings much better on the faceplate. I unscrewed the cover and got my vacuum out to get all the nasty bits and bunnies out, but even with a small stiff paint brush, only some layers would lift out. Next, the air compressor running an outlet pressure of 60 psi in a not so small nozzle got a lot more out of the heavier stuck on pieces. I ran it at 60 psi because I didn't want to damage any components, but if you have access to one, then you have to be the judge from the look of the dirt, dust, and grime.

I then still didn't like the looks of the board, took it all to a friend and we disassembled it made sure there wasn't anything fragile or non-resistant to water (heatsinks had an odd little fan), and then washed it. We took very dilute very warm soapy water (we used Johnson&Johnson Baby Shampoo for the lack of anything better on-hand and mainly as a lark because we decided that dish soap was soap sticky to rinse off easy) and 1" paint brushes with natural bristles and went to town on it. We scrubbed it and the water that ran off was filthy yellow and smelled like an ashtray (I used to bartend in my younger years and all I can say is, GROSS). Rinse and repeat. It was still pretty yellow the second time around, but much better for the effort. Rinse copiously with clear warm water.

Got out my air compressor and blow and still add water as the rinse water was showing streaks of yellow water left over. This thing was dirty! Then satisfied, I blew dry the board as best I could. I planned to leave the boards to dry for a week in front of the register at home just to be safe. Ended up more like two weeks in front of the registers as I ended up doing something else.

Checked out for any damage or possible problems. Put it all back together, thank goodness for digital cameras and notes, and powered it up nervously. The power up was really nerve wracking because I never did this before and didn't want bluish smoke or sparks.

It worked. And sounded quite nice. I could get over the fact that it smelled like J&J Baby Shampoo for months after that.

Got to remember, it was cheap, I didn't care that much since it was only $12, I could harvest heat sinks that were made into a cooling tunnel with forced air, the power cord, and all the knobs. All that was worth more than what I paid for it. I ended up selling that one to a friend and have recently stumbled on another B-1000 in clean condition with not a dent or scratch for $20 at the same store.

Point of all this is, you know your limits and pain threshold, you also can see what you are dealing with and the extent of dirt on the gear, you also know your tools. Any time you feel uneasy or whatever, then back off and re-think or leave alone.

aras84 15th November 2012 04:10 PM

Quote:

Originally Posted by overtheairbroadcast (Post 3242635)
I agree with Mooly, most don't need a wash. However with that said, I bought a nice Sansui B-1000 amplifier for $12 at the used charity store and it was likely owned by a smoker as you could just smell it after picking it up.

After some Windex, I could see the lettering and markings much better on the faceplate. I unscrewed the cover and got my vacuum out to get all the nasty bits and bunnies out, but even with a small stiff paint brush, only some layers would lift out. Next, the air compressor running an outlet pressure of 60 psi in a not so small nozzle got a lot more out of the heavier stuck on pieces. I ran it at 60 psi because I didn't want to damage any components, but if you have access to one, then you have to be the judge from the look of the dirt, dust, and grime.

I then still didn't like the looks of the board, took it all to a friend and we disassembled it made sure there wasn't anything fragile or non-resistant to water (heatsinks had an odd little fan), and then washed it. We took very dilute very warm soapy water (we used Johnson&Johnson Baby Shampoo for the lack of anything better on-hand and mainly as a lark because we decided that dish soap was soap sticky to rinse off easy) and 1" paint brushes with natural bristles and went to town on it. We scrubbed it and the water that ran off was filthy yellow and smelled like an ashtray (I used to bartend in my younger years and all I can say is, GROSS). Rinse and repeat. It was still pretty yellow the second time around, but much better for the effort. Rinse copiously with clear warm water.

Got out my air compressor and blow and still add water as the rinse water was showing streaks of yellow water left over. This thing was dirty! Then satisfied, I blew dry the board as best I could. I planned to leave the boards to dry for a week in front of the register at home just to be safe. Ended up more like two weeks in front of the registers as I ended up doing something else.

Checked out for any damage or possible problems. Put it all back together, thank goodness for digital cameras and notes, and powered it up nervously. The power up was really nerve wracking because I never did this before and didn't want bluish smoke or sparks.

It worked. And sounded quite nice. I could get over the fact that it smelled like J&J Baby Shampoo for months after that.

Got to remember, it was cheap, I didn't care that much since it was only $12, I could harvest heat sinks that were made into a cooling tunnel with forced air, the power cord, and all the knobs. All that was worth more than what I paid for it. I ended up selling that one to a friend and have recently stumbled on another B-1000 in clean condition with not a dent or scratch for $20 at the same store.

Point of all this is, you know your limits and pain threshold, you also can see what you are dealing with and the extent of dirt on the gear, you also know your tools. Any time you feel uneasy or whatever, then back off and re-think or leave alone.

I really wondered, do you have a before and after picture of it :)

nigelwright7557 15th November 2012 04:20 PM

Things that go with age are switches, pots and electrolytic capacitors.

jneutron 15th November 2012 06:04 PM

I used the plastic insulating pads for high power transistors...every decade or so I make sure the screws holding them down are tight.

j

jcx 15th November 2012 06:33 PM

dishwasher detergent likely leaves less residue - no "conditioners", perfume (well less - virtually all consumer soaps have some perfumes - if only to make them "scentless")

for high Z circuitry board surface current leakage can be a problem - after the soap and water do a distilled water rinse, followed by isopropyl alcohol - the alcohol removes finger grease, dries out crevices, tight spots the water is clinging to by capillary action

lanchile 16th November 2012 01:12 AM

if you have a little knowledge, check for dc offset and bias voltages (get schematic). the usual problems are mentioned above also if you open the bottom plate of amp, check for bad soldering joins, these Sony ES are well known to get very hot. I would use a vacuum with a soft brush to clean inside. When I worked fixing TV's, Stereos, Amps etc with a technician, We only did it that way and it is very good and safe.

PS: When you clean inside of your amp, make sure it is UNPLUGED!!!;)

aras84 22nd November 2012 05:24 PM

Hi all, After Cleaning...

http://img856.imageshack.us/img856/1618/93138042.jpg

http://img217.imageshack.us/img217/7964/33200653.jpg

http://img197.imageshack.us/img197/463/64817446.jpg


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