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
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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
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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.
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.
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.
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.
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
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
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!!!
PS: When you clean inside of your amp, make sure it is UNPLUGED!!!
Hi all, After Cleaning...
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Whaddya wanna know
They are "normal" output transistors (bjt is bipolar junction transistor). Most transistors big and small are bjt and are used in most designs unless it happens to be a FET device
Bipolar junction transistor - Wikipedia, the free encyclopedia
Along that line I was restoring a 1978 Ampex AVR-3 2" broadcast VTR. I removed all the power transistors (and there are LOT in there) and found the heatsink grease no longer grease, just the zinc oxide powder. I cleaned the residue, checked each transistor on a curve tracer and if it was good (all but 1) re-greased and re-installed. I guess the greased mica could have been replaced with silpads
TO-3 Transistor Silicon Insulator,Insulation sheet,x 50 on sale - electronic parts and components supply store
G²
The old original unobtainable depletion mode V-FET's and todays Lateral FET's are claimed by many to have valve like characteristics but as with most things there is a lot more to it than that. Good amps (that sound valve like if thats what you want) can be made with all device types including bjt.
Its the latest point contact protection device... as the leg warms it parts contact with the PCB thus opening the circuit
(Very well spotted, maybe its an effect of the lens/light but it does look highly suspect... check it out aras84)
I really wondered, do you have a before and after picture of it
I never took pictures of it because I never think of doing so because I have cleaned up so many (I am sucker for a bargain). After that experience (and having kids) I may have gotten a little snobbish as I will pass up on what I considered, "okay integrated amps but dirty as all heck however Windex and some time will so some wonders".
It had better be something special (like a SPEC-2, a KRELL KSA-50, an ST-70, or an inch of grime covered Marantz 8b) before I get back up to my elbows in suds and stink up my garage while using my shopvac again.
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