What is the difference between tuner cleaner and contact cleaner?

Not much, since many vendors sell a product that does both. Sometimes either one claims to "lubricate" the contacts, which means that it leaves an oily residue.

Any particular cell phone? Not all EP connectors are the same. If in doubt, use an air hose to remove the accumulated lint and filth. If the contacts are exposed, sharpen a pencil eraser to a point and use it to clean the contacts. Then use the air hose to remove the crud.

It's almost certainly the solder connection between the jack and the PCB. Open her unspecified model cell phone, clean out the filth, and resolder the connector. If the connector appears to be cracked, replace the connector.

Sorry, but I couldn't find anything under proprietary plug.

I wouldn't use either type of "cleaner". Some 90% alcohol to disolve out any grease left by the previous attempt to use tuner/contact cleaner. If that doesn't work, tear the phone apart.

I was taught many years ago NOT to use a rubber eraser to clean contacts. The theory was that the rubber might leave a sulfur containing residue that will encourage corrosion.

You may agree or disagree but prudence (a fine girl) dictates caution.

Yeah. It's a Sony Ericson W580i.

Okay.

Okay. Although the first cleaning caused it to work fine for almost a years.

Okay.

I'll be able to find one for sale? (Don't waste your time looking. After all, I haven't said it's cracked yet.)

I don't know what was used the first time. I wasn't involved. Right now I don't even remember if she did it herself or she went to a phone store.

I'd like that, but she may not trust me.

There are plenty of used cell phone dealers around.

etc...

Plenty on eBay. New for $90. Used for $35 to $50. Some auctions at low prices. Search for W580i.

In this case, probably not. Here's the connector:

What's probably happening is that the gold contacts in the phone have developed a layer of crud on them, and the sharp points on the plug are not penetrating the crud. Solution... remove the crud. I have several old phones with similar connectors. What I used was a tiny screwdriver or plastic pick as a scraper. Some household cleaner (i.e. 409), and a pair of overkill magnifying glasses so I can see what I'm doing. The trick is to scrape off the crud until you see the gold underneath, without scraping off the gold, or destroying the plastic insulation between contacts. Start with a toothpick. Graduate to a metal scraper if that doesn't work. You'll probably also find a substantial amount of pocket lint inside the connector, which needs to be removed BEFORE attacking.

The phone store usually has a spray can of something. I've never bothered to check what they use.

I wouldn't trust you with my phone either.

I just googled for "contact cleaning eraser sulfur" and found no warnings or horror stories. Sulfur is not going to attack the gold. It might coat it, but then it has to leak out of the eraser in liquid form, such as in the form of sulfuric acid. That's not going to happen.

If the gold contacts develop a hard black coating, then some sulfur was transfered. However, I've been using Pink Pearl erasers on gold edge connectors for ummm... too many years, and have never seen the problem. I wash off any residue with whatever solvent or cleaner falls off the shelf (usually 409). I do NOT use an ink eraser, or highly abrasive eraser that might rub off some of the gold plating which is only 25-50 millionths thick.

There are those that favor DeOxit or Cramoline. I've had good luck with both of those, but not when the contacts are exposed to a filthy environment, as is typical for the exposed contacts on a cell phone. The residue picks up the dust and lint, and turns them to crud. For cell phones, I suggest using something that leaves no residue (alcohol).

Connector cleaning by Apple Computah:

The only specific characteristic of "tuner cleaner" that I'm aware of is that it's (was?) formulated to not be aggressive on plastics. Back when mechanical tuners were made, they generally had phenolic wafers to hold the contacts, but some used plastic or had plastic elsewhere in the tuner. Tuner cleaners were generally pumped into various openings in the tuner in order to flood and shotgun the whole assy, rather than disassemble the tuner and apply the cleaner only to the actual contacts. Other contact cleaners may or may not be tough on plastics.

Use a plastic eraser (used for erasing marks from mylar sheets). These are available at drafting and art supply stores.

A pretty shabby troll attempt.

the russians lacked food in the cold war era.

That'd be because they didn't have any WD40

Tuner cleaner might be designed to avoid damaging plastic parts in tuners, whereas contact cleaner might be more "aggressive".

I would get some red Cramolin (that's not what it's called any more -- can't think of the name) and thoroughly clean the plug. (You can also put a "wet" plug in the jack. The cleaner will migrate and at least partially clean the jack.) This removes the oxide, which might be what you need done.

Some "tuner cleaner" I have used in years passed, also contained a light lubricant (mineral oil, I think). Mechanical UHF television tuners contained both rotary switches, and a whole bunch of tunable reactive components (slug-tuned inductors?) which benefited by a bit of lubrication.

I understand that some Cramolin products are still available from the original manufacturer in Germany.

Caig Labs used to import Cramolin into the U.S. and sell it under their label. In more recent years, they've been selling DeOxIt, which is a similar product (but not manufactured by the makers of Cramolin).

The makeup of Cramolin and DeOxIt products is, I believe, a trade secret. I've read several reports which suggest that both types of products contain oleic acid as the (or an) active ingredient, as this has a long history of use as a metal and contact cleaner.

This explains the tangled history of Cramolin:

More useful info on Cramolin or whatever it's called this week: