On Mon, 01 May 2017, Micky wrote:

WD-40 to clean electric contacts?

I'm on vacation and renting a room, and my landlady has a combination
CD/Radio/Cassette?, very compact, portable, works well except fo the
little on/off/CD slide switch.

The switch doesn't easily make contact, even when pushed to and past
the On position. So it's hard to get the radio on, and it turns off
by itself in about 30 minutes. Moving the switch back and forth 10
times to clean it hasn't worked yet.

Normally what I would do is spray contact cleaner or tuner cleaner in
the switch from above, where the plastic slider that goes over the
switch is, And normally that doesn't accomplish much.

Even taking such things apart and spraying the switch from underneath
has taken longer to work than for rheostats, for example, and here I
don't want to take it apart. She's only my landlady.

I don't know where in this non-English-speaking country to buy
contact cleaner and she might balk at the extra money, but she does
have something in an aerosol can that looks mighty like WD-40.

I have this vague recollection that WD-40 is good to clean electric
contacts?? Either that or it's bad for them. Should I try it.

BTW, I want to use the radio, so that's one big reason I want it
fixed. When it stopped playing while she was there, she said, "Oh,
yeah, maybe that's why I bought another one" (She speaks English.)

I never knew WD40 could work with non-metal. Look at this CD unjamming article:

Muskegon Chronicle: Stan Harrison: Jammed DVD/CD tray? Fix it yourself for less than $1 - Mar 4, 2012 It's happened to you. I know it has.

Getting started (middle of article)

Unplug the DVD player and take it to your workshop. Make sure you have a clean surface and plenty of light. A flashlight can help when looking at small parts. You'll need a small Phillips screwdriver, a small flat-blade screwdriver, a cotton swab and some WD-40 lubricant.

First, look at the underside of the player. On some models, there's a slot that might say something like this: "For ejection, insert a pin and push to left." In other words, if the DVD tray is stuck -- like yours is -- stick a straightened paper clip or narrow screwdriver in the slot and push it to the left. Voila! The tray will pop open, and you can retrieve your DVD. If you can get the tray open, leave it partially open. It will make removing the cover of the DVD player easier.

And that's the next step -- removing the cover. Carefully study the case and remove any screws that look as though they're holding the cover in place. Be sure to sort the screws. Tape them to a sheet of paper and label them so you'll be able to properly reassemble the player.

Once you've removed the cover, you should be able to easily slide the tray open. If you can't, don't force it. Forcing the tray could strip or damage the gears, and then you will indeed be buying that new DVD player. Instead, use a small flat-blade screwdriver to press against the cogs on one of the gears beneath the tray. You may have to tip the player on its side and peer into the tray slot with a flashlight. As you push the screwdriver to rotate the gears, the tray should start to slide open.

Replacing the broken belt

Once the tray slides open, you should be able to see a small motor, some gears, and if you're lucky, a broken belt. Remove and keep the broken belt for size. If the belt is missing, take a piece of string and snugly wrap it where the belt should be. Mark and cut the string to size. This will be the size of your replacement belt.

Now for the cheap trick. With the broken belt or piece of string in hand, head for the plumbing section -- that's right, the plumbing section -- of your hardware store or home center. You'll want a rubber O-ring, which is typically used to repair leaky, dripping faucets. Find an O-ring that matches as closely as possible the size of your broken belt or your piece of string. If you can't find an exact match, go for the slightly smaller size.

Put the rubber O-ring in place on your DVD player. If the tray struggles to open or close, the O-ring may be too small. If the next size up is too large, try flexing the O-ring a bit to loosen it up.

Now, using a cotton swab, apply a small amount of WD-40 to the tray guides (groves along the bottom of the tray) for lubrication. This will help the tray glide more easily.

Reattach the cover (you do remember which screws go where, right?) and you're back in business!

Not only have you saved yourself $40, but by not tossing your DVD player into the landfill, you've helped save the planet.

You've just finished watching your favorite movie on DVD, then press the eject button on your DVD player.

Nothing happens. You press again. And again. And again. The tray is stuck. Now what?

You could take your DVD player to the nearest electronics repair shop. But they'd probably charge just as much or more to look at it as it would cost to replace it. So unless your DVD player is still under warranty or you've purchased an extended warranty, you're out of luck.

Instead, you resign yourself to purchasing a new DVD player, one of those inexpensive ones for less than $40. You pry your stuck player open, retrieve your DVD, junk the now-damaged player and head to the nearest big box electronics store.

Save yourself that $40. Sometimes simply unplugging the player for a few minutes will reset the electronics, and you'll once again have a fully functioning DVD player. If that doesn't work, don't give up yet. For a trip to a hardware store or home center and less than $1, you still might be able to fix that stuck DVD tray yourself.
The DVD tray is connected to a series of gears, a motor and a rubber belt. When the motor is engaged, it turns the belt, which in turn moves the gears that open or close the tray. The problem typically is a broken belt. The motor turns on, but with no belt, it can't turn the gears that operate the tray.

Of course, you could try to buy a new rubber belt online -- if you can find one. But even though the cost of the belt itself wouldn't be much, the cost of shipping would hardly make it worth your while.

(Start of article)
So what'll it be -- $1 or $40? There's nothing to lose. Even if you mess up while attempting your own repair, you simply end up buying yourself a new DVD player anyway.
-- http://www.mlive.com/homeandgarden/i...dvdcd_tra.html