I have a boombox in the bathroom and every morning it will lose it’s volume. I pull the plug, plug it back in and the volume comes back up again for a few minutes and then it will do it again. Why is this happening and how can I stop it?
K.
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Well my first thought would be that the transistors/capacitors and resistors lose efficiency as heat and elecrostatic charge builds up (especially in a humid environment like a bathroom). The act uf removing the power source discharges the charge and allows them to cool.
thats my WAG anyhow.
Your boombox could have some type of automatic volume adjustment… look for a switch (particularly if it’s a Sony) that says “AVLS”. Basically, it adjusts the volume lower every time there’s a particularly loud section, in order to keep you from blasting your ears apart. I’ve only seen it on discman-type stereos, but it could be on a boombox. Worth a shot!
Volume amp circuit is failing (Yeah I know… “Duh!”). Doubt it’s due to external heat or humidity unless volume failure mode only happens in bathroom. Not much you can do unless unit is in warranty. Boomboxes are rarely worth fixing out of warranty unless they are pretty expensive.
The unit’s about 10 or 12 years old and it only started doing this a year or so ago. I have always kept it in the bathroom so it’s unknown whether the problem would happen in another room.
It wasn’t a hugely expensive item but it has served me well and I would really hate to have to replace it for the sake of a duff transistor/resistor…however if I must…
K.
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I just couldn’t resist ! (re: sleeping with pets)
The unit sounds like it is on the way out anyway, so you probably can’t break it much worse. If the volume control is a slider type it’s easier to try this. Get some WD-40 and spray a little in the volume control -unplugged unit- and really twist or slide the hell out of the volume switch. The resistive contacts get intermittant from moisture attracting dirt and dust and WD-40 tends to displace this. Give this a try, you don’t have much to loose. Good luck.
later, Tom
Gee, hflat, WD-40?
Wouldn’t contact cleaner be a better choice? It should do the job better, and will evaporate leaving absolutely no residue behind.
Aerosol contact cleaner is sold at Radio Shack and other electronics supply places; but, you can get it in a larger-sized can (for the same price that RS sells its small-sized can) at an auto supply stores. The stuff is a very, very handy solvent to keep around the house/workshop, so I’d suggest going the auto supply route.
Gee, hflat, WD-40?
Wouldn’t contact cleaner be a better choice? It should do the job better, and will evaporate leaving absolutely no residue behind.
Aerosol contact cleaner is sold at Radio Shack and other electronics supply places; but, you can get it in a larger-sized can (for the same price that RS sells its small-sized can) at an auto supply stores. The stuff is a very, very handy solvent to keep around the house/workshop, so I’d suggest going the auto supply route.
Sometimes things just come back and bite you in the butt. Fyi hflathead, hubby and cats are ALL still sleeping in the bed (as in no-one has been banished to the couch yet). Anyway, thanks for the suggestion, it may be worth a shot…especially since, as you say, it seems to be on the way out anyway. Perhaps I’ll try the contact cleaner first. Thanks to all for the responses.
K.
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While you are at Radio Shack ask for a can of freeze mist. It comes in an aerosol can. Take the back off the boom box and the next time it acts up spray the Output transistors.It is safe to do this while the equipment is operating. A small blast is all that is needed.They are usually mounted on a metal surface and held in place with screws. If that “fixes” the problem try to isolate the individual culprit. If it does not “fix” it spray one section of pc board at a time. Spray the component side.
Sometimes it is a cold solder joint. This is caused by the component getting so hot it melts solder. Generally the outputs are the only ones that get that hot but I’ve seen it in other sections of equipment.Inspect the solder side of the pc board. Use a magnifing glass and look for discolored solder. A “healthy” connection is shiny. If it is dull it is suspect. To fix a cold solder joint heat the solder with a soldering gun until it melts adding a little solder and let it cool.Be careful here you may short out something. It is best to unplug the equipment before soldering .
[hijack]
Never say anything in an electronic form that you wouldn’t want the entire world to see, because ten years down the road, it’ll show up in some search engine result.
Not that I’ve ever said anything I would later be ashamed of.
[/hijack]
HOORAY! HOORAY! HOORAY! 
Actually WD-40 is great for cleaning contacts and it also carries current quite well. I suspect that most modern “contact cleaners” are very similar to WD-40 but even if not the advantage you have with WD-40 in her case is she is using it in the bathroom and thus the “Water Displacement” element of WD-40 comes in to it’s own.
I used to drive an International Scout (74’) and had one major flaw in that the distributor cap was not all that water resistant (seemed to be a design flaw as I replaced distributors and cable sets and still had the same problem) and when I would go scouting for elk during rainy days I would sometimes stall out because of water in my distributor. A friend who had a similar issue told me about using WD-40 and I tried it and it worked. I ALWAYS keep a big can in the car now (tho’ I no longer have the scout). Never know when that stuff will come in handy.
My car toolkit:
two rolls 100mpg tape (one green one silver)
one large can WD-40
several wire coat hangars
Tin snips
a butter knife
my Leatherman
about 100yds of twine all knotted up.
Toothpaste (Tom’s of Maine Spearmint)
I can fix anything with the above list.
All right zen Whats the butter knife for???