September 24, 2014 at 03:40 pm

Car medicine in the service of computer technology: another way to clean contacts

Electronics for beginners

A situation familiar to everyone. You are watching your favorite movie. At the most interesting place, the TV screen goes blank. Instead of a picture, the message: “Check the signal cable”, “No signal”, “Check the power of the connected devices”, etc. Diagnosis in this case is simple:

pull out and insert the cable several times from the connectors at both ends;
if it doesn't work, try another cable;
if another cable does not help, try to find out on which end the problem is: connect a TV instead of a monitor to a PC; connect a monitor from a PC to a media player, etc.

If nothing has changed after such an experience, most users go to the store to buy a device that turned out to be faulty: a TV, monitor, media player, etc. There are also “middle and half” solutions: for example, instead of HDMI, connect a device via composite, DVI, VGA - whoever has what. But still, these are half measures: you will be haunted by the thought that the device is faulty, that something else is about to burn in it, etc. It will need to be changed soon anyway.

Or maybe you don't have to?

Suddenly it is correct?

Experience shows that 99% of such cases occur due to oxidation of contacts, and not in the cable, but on the device itself. (This happens especially often when it is already cold outside, and the batteries have not yet been turned on - it is damp in the houses, everything rusts especially quickly here). Yes, you once bought a quality wire with gold-plated connectors. But the monitor manufacturer may not have taken care of this. It is impossible to verify what material he used to make the contacts. Well, why not pay 15 thousand for a new monitor because of this?

It offers a simple and safe way to clean absolutely any contacts. No cotton swabs, no alcohol or cologne required. Everything is so simple that it is embarrassing to even describe it somehow.

Turn the device with the connector up;
Take a can of WD-40, insert the tube from the kit into the sprayer, place the tube close to the connector and press the head. It is necessary to spray abundantly, do not be afraid if something gets inside the case. Nothing will be done to him;
Immediately, while the lubricant has not yet leaked, we take the mating part of the connector and insert / remove it several times in a row;
We repeat paragraphs. 2-3 again, another for fidelity;
We repeat paragraphs. 2-4 for the second device and for the second end of the cable;

After that, we assemble the system and check if it works.
If it works, do not rush to put the equipment in place. Turn the connector down, put a napkin on it and let the rest of the “medicine” drain off.

How it works?

It is worth familiarizing yourself with this drug in more detail. Its composition is very simple: 50% white spirit, 15% mineral oil, carbon dioxide and some "inert ingredients". Nothing conductive, so there is no danger to electricians. Since the materials are combustible, care must be taken only that there are no open flames nearby, that nothing sparks or overheats. White spirit evaporates over time, and the oil forms a thin film, which subsequently slows down the oxidation of contacts. In addition, if dust gets into the connector, it picks up moisture and also becomes conductive, which can lead to equipment failure. It is not always possible to remove these particles, but if they are oiled, the likelihood of shorting becomes much less.

Isn't it dangerous?

Theoretically, I will not say anything. But here are some experiences.

Of course, I didn't come up with it myself. The first time I encountered such an “electronics repair” was when the ignition suddenly failed in my car right on the highway. A call to a familiar electrician, advice: clean all the contacts with a Vedeshka. After 15 minutes, I'm moving on.

Some time later (just before the start of the heating season), when I turn on the computer, I hear a disgusting squeak: problems with memory. Mac Mini computer, Kingston memory, two 4 GB modules. Replacing the modules did not solve the problem, which means there are problems with the motherboard, and it is not cheap there. Out of desperation, I decided to repeat my road experience: I splashed all the memory banks with a VDE, installed / removed modules several times. Turned on the machine - hurray, earned! Naturally, immediately memtest all in single user mode - no problem. Since then it has been working flawlessly.

DVI connector stopped working in Acer monitor at work. Temporarily connected via VGA and began to beg the authorities for a new monitor. Where there ... And again, this simple procedure solved all the problems.

And finally - the case with which this article opens. Samsung TV, BBK media player are connected via HDMI. 10 minutes later we were already watching the movie.

conclusions

It turns out that a simple liquid that everyone is used to lubricating locks, bicycle chains, unscrewing rusty nuts and the like can actually extend the life of complex expensive equipment. Of course, this can save money for owners of this very technique. But more important, perhaps, is how much pleasure it can bring to various owners of crazy hands.

Important addition

Especially for novice electronics - all manipulations with repeated removal / insertion of connectors should be done only by disconnecting both devices from the network. This also applies to those interfaces for which the standard allows a “hot” connection (for example, HDMI, USB): it’s one thing to plug it in once, it’s another thing to pull it under current.

And, of course, you don’t have to do this with devices that are under warranty - let the service center change everything for you for free. And "traces of foreign liquid" can serve as a basis for voiding the warranty.

Sulfur, sulfur ... I wrote "silver SULFIDE" (formed when silver is left for a long time in an atmosphere of sulfur compounds emitted by the same rubber, for example) and "silver OXIDE" (natural deep black patina on silver products, including contacts , when silver is in the atmosphere upon contact with oxygen, it is especially actively formed in an atmosphere of ionized air, under the action of ozone.And the TV is a fairly powerful ionizer) create LOOSE films that are easily erased by mechanical action (during the operation of the switch). In addition, soft silver itself wears out when the contacts are rubbed. Thus, the natural removal of silver is still going on, but INCOMPARABLE in intensity with deliberate abrasion with abrasive materials.

Unlike silver oxide, copper carboxide films (copper patina - chemicals formed on copper, brass, bronze surfaces in air with the participation of carbon dioxide and water, which are always present in residential air) are very durable (mechanically, naturally: mechanical and chemical strength - concepts from different songs) and abrasion are very tight, and at the same time they have the ability to quickly grow again.

From all this: a new switch, even a fair amount of time lying in the warehouse, with absolutely black SILVER PLATED contacts will work fine after two or three turns, when the silver patina is worn off. The switch, even with slightly oxidized copper contacts, can thus be made to work for a very short time, and you can’t really count on “cleaning” by scrolling - the fighter’s hand will get tired of twisting ...

So, even channel switches with lamellas ALREADY rubbed down to copper and nickels of "dice" contacts CANNOT be cleaned with abrasives: even in the worst case, they can provide, albeit unstable, but good contact on silver at the edges of a worn field. Mechanical cleaning, on the other hand, “destroys” silver plating completely, even with a gentle approach, erasing silver at the wear boundaries. Actually, this applies not only to the PTK, but also to all switches with silver-plated contacts.

Although, in general (I hope) everyone understood that the exclusion of abrasive cleaning is, after all, a joke of humor, because more effective methods to achieve at least a temporary improvement in the operation of a worn switch did not exist in those days and hardly exist now. True, an abrasive eraser is, of course, a very cruel tool. In this case, I used a piece of paper moistened with kerosene and lightly rubbed on both sides with "Razor Straightening Paste" (GOI paste can be used) - they have less abrasiveness (grain size) than gum. In addition, there is no need to try to clean the contacts to a "metallic screech" entirely - it is the "patch" of the dies themselves and the contact zone of the lamellas that need to be cleaned. This will eliminate or at least reduce wear on the silver in the surrounding areas. So I did, clamping the strip between the drum and spring lamellas and turning the drum several times. Then, stopping the drum on an inactive channel, he pulled out a strip - this way the lamellas were cleaned. After that, the Polish aerosol "Kontakt" was puffed onto the cotton wool (I, unfortunately, I don’t remember the brand now - it was supplied for the same purposes with the ZIP for typewriters "Consul", provided lubrication and protection against oxidation of the contacts of the encoder of the machine), wiped the contacts with this cotton swab drum (until the remnants of abrasive metal dirt were removed after cleaning the contacts), and turned the switch a couple more times (to cover the lamellas with "Contact"). And anyway, even with such a "scientific" approach, if there are obvious "paths" to copper on the lamellas, it made no sense to guarantee the operation of the switch for more than two months (and even then - with the active use of the switch). a slight shift of the lamellas to the side helped to slightly improve the operation of the switch, so that the nickels would contact with the silver coating that was not worn off. Unfortunately, it is impossible to "turn" the patches themselves, and yet they are in contact with the lamellas already with copper, so it was still impossible to give a guarantee "as for new". In my mind, a worn switch should have been stupidly changed.

By the way, both silver oxides and copper carboxylic compounds dissolve perfectly with an ammonia solution (ammonia) and jewelry cleaning compounds with its content, however, the use of these compounds and pure ammonia to clean contacts is even more sabotage than cleaning with abrasives (five years of execution without the right to correspond, every day is deadly). Explain why? Buckoff will be no less...

What and how to clean contacts? Why, in general, do we need processing, protection and lubrication of contacts? We will answer these and other questions in this short article.

It just so happened that the electrical system is a little deprived of attention from car owners and they remember it only when either the next lamp has gone into the world of forever extinct things, or when at the most inopportune moment the starter does not respond to turning the ignition key.

It is also worth noting that due to faulty wiring, most car fires happen and this happens instantly and unpredictably.

Therefore, the electrical system, like all other vehicle systems, requires regular maintenance.

Moreover, in our time, this procedure is even more important than before. This is due to two reasons:

cars have become literally crammed with electronics
application of engine management systems

Well, the first reason is clear - the more wires, the more possible problems.

And why does the engine management system require increased attention?

This is due to the use of lower voltage in the engine control wiring and the use of pulse signals.

The point is that the higher the voltage, the lower the losses.

And what do we get? Previously, only 12V was used in the electrical equipment of cars, or, on some, 24V. And now the ECU works mainly with a voltage of only 5V, and some sensors even with millivolts.

Ignition systems have become more powerful and are no longer controlled by a banal closing / opening of contacts, but by pulses of a certain duration, set by the control unit.

All these low-current circuits must always have a minimum and constant resistance, and they work in constant temperature changes among the oily and dusty air under the hood. Condensation, puddles on the roads, constant vibration and corrosion inevitably make their own adjustments to the system.

I can say with confidence that the lion's share of all problems in the engine management system is related precisely to the condition of the wiring.

And the weakest link in this chain are all kinds of contacts and connecting blocks.

How to clean and protect contacts?

All contacts sooner or later begin to corrode and become covered with nasty oxides, disrupting the system.

Therefore, the question logically arises - with what and how to clean the contacts?

It is highly undesirable to clean the contacts mechanically. And in modern systems, you can’t really get close to them. Folk methods with an eraser, soda and the like do not give the desired result. And the application of these ancient methods in the 21st century I consider the fight against windmills.

As a radio mechanic, I have long been using modern chemistry in solving these problems. The same chemistry has successfully burst into the automotive industry.

From practice, as for me, two such means deserve special attention.

Grease for electrical contacts

One of them is Contact 61.

And the second is Liqui Moly Electronic-Spray

It is a product for cleaning, lubricating and protecting all kinds of electrical contacts, both low voltage and high voltage.

The price tag of these funds is not quite budgetary - 200ml costs us 180-200 UAH. (about 8 American money). But it's worth it, believe me. Moreover, it will last you for a very, very long time.

One treatment is enough for at least a year, so one hour of time spent once will give you confidence for the whole year that at the most crucial moment the contacts in the wiring will not let you down.

There is very little information on the Internet and other sources about Liqui Moly Electronic-Spray. Therefore, it is reasonable for many to have certain questions. One of the main ones is whether this tool conducts current and will there be short circuits and leakage currents?

I have been using it for a long time and I can say that it is quite the opposite, it prevents stray currents, current leakage, contact heating, sparking, as it improves contact by filling microscopic cracks and roughness on the contacts.

I find application for it wherever possible - car radio contacts, connectors of various sensors, limit switches, battery terminals, lamp contacts, adapter connectors, switches and switches, ignition system, etc. And that's just in the car! And in everyday life and repair of all kinds of equipment, there are no less applications.

There was a case with a VAZ car. The man asked to see where the turn signals had disappeared from his car. He spent the whole day looking for a problem, already replaced the steering column switches, but the problem was not solved.

I just processed the alarm button in five minutes with such a tool and returned the blinking look to the car. Even without replacing the button!

This spray is very easy to use. If the contacts are not very dirty, then we spray quite a bit on the contacts and connect the connector in place. If the contacts are dirty, then we also puff and wait until the violent reaction ends with the release of foam and connect everything back. If the contacts are very dirty, then we puff, wait 10-15 minutes, remove the muddy dirt with rags or compressed air and repeat the treatment again. But the latter option is extremely rare and usually everything is cleared the first time.

There are products separately for cleaning, separately for lubrication and separately for protection and moisture displacement. For example, the Contact series has a lot of them, sharpened for a specific task. Kontakt U - rosin and flux cleaner, Kontakt S - contact cleaner from oxides and sulfur compounds, KONTAKT 60 - anti-corrosion protection of contacts, etc.

But KONTAKT 61 and Liqui Moly Electronic-Spray products are positioned as universal. So to say, a budget option.

Their price and properties are almost the same, so decide for yourself what to choose.

Attention! Be careful and always be aware of your actions. This article is about a universal contact protection agent with a light cleaning effect! On sale there are means specifically for cleaning contacts. Either out of ignorance, or negligence, but the sellers do not warn that after the contact cleaner, the contacts must be protected with a contact protector !!! Otherwise, the contacts "turn green" and the treated surfaces are literally corroded. Including the board in the engine control unit. The car becomes unusable and requires expensive repairs. There are not many such cases. Be careful! I mentioned this in the video at the end of this article.

How to clean contacts

First of all, I advise you to process the knock sensor connector and the connectors of other low-voltage sensors.

Attention! I do not advise processing the oxygen sensor connector in this way! The reasons are stated in the article about

Battery terminals.

It is worth noting that for the terminals there is a special lubricant in Liqui Moly "Batterie-Pol-Fett" tubes. But I only use the spray.

Wiring harness connector

And, of course, the connector of the ECU itself

You also need to pay attention to temperature sensors - air and coolant, contacts of the camshaft position sensor, generator and starter. Well, definitely

Separately, I would like to dwell on the elements of the ignition system.

The processing of contacts of high-voltage wires and ignition coils must be performed one of the first. Both for prevention, and if dips and twitches appear on your car when you sharply press the gas pedal. The thing is that if there are problems in the ignition system, then they will manifest themselves precisely during hard pedaling. This is due to the fact that the breakdown voltage is influenced by several factors, and one of them is pressure.

At idle, the pressure in the cylinders is not high, and at the moment the throttle is opened, it increases sharply, increasing the breakdown voltage at the spark plug electrodes. And if there is a defect in the ignition system, then it will definitely show its influence at this very moment. We will talk about this in one of the next articles.

So, one of these defects is often a slightly increased contact resistance in high-voltage wires and, especially, in low-voltage connectors of ignition coils. Moreover, a conventional multimeter will not show this.

And very often, cleaning and protecting contacts helps to correct the situation. Delov for three minutes, and the result for the better will be 100%!

Moreover, if the car is more than three years old, then this procedure is simply mandatory.

First of all, we process the low-voltage contacts of the ignition coil. Remove the pad and apply the spray

Next, lubricate the high voltage contacts. To do this, it is not necessary to pour the cleaner into the coil leads themselves, but it is enough to apply the agent to the BB wire, put it on the coil terminal and twist it back and forth slightly. It is also necessary to hold the wire with the contact up so that the spray penetrates deeper - into the junction of the tip with the wire itself.

We do the same on the other end of the wire.

I advise you to do this procedure even on new wires and coils.

The same applies to other contacts and connectors. If you put a new sensor or connect a new car radio, be sure to spray the contacts. After all, the main task of these tools is not only to clean, but also to create a microscopic protective film on the contacts. This film protects the contact from moisture and air, preventing oxides and corrosion.

And do not forget about the mounting blocks of fuses and relays. Pulled out the relay, processed the connector and put it back in. Nothing tricky

After these simple procedures, you will definitely notice that the behavior of the car has changed for the better! And the engine management system, electrical equipment and ignition system will work easier, which will result in an increased resource of the entire engine as a whole.

Here is a video about processing and protecting contacts

Peace and smooth roads to all!!!

The modern chemical industry produces a variety of useful products for cleaning and protecting electrical contacts from corrosion and oxidation. But do not discount the recipes for such cleaners, as they can also come in handy when working with certain devices. This article describes several chemical formulations available for cleaning and protecting contacts.

Contact cleaners are relatively easy to make at home, and you don't need any exclusive materials.

After any of the above cleaners, you need to move the contacts so that the composition gets into all meta of the treated surface. You also need to wait about 15 minutes for the solvent to evaporate, after which you need to wipe the contacts with a cloth to remove dissolved dirt and excess solvent.

How to make electrical contact cleaner recipe one:

You need to mix the substances in a glass jar in the following proportions:

250 ml concentrated aqueous ammonia,

750 ml of methanol (this substance is poisonous) or ethyl alcohol denatured with gasoline.

Store the mixture in a well-closed glass container.

How to make electrical contact cleaner recipe two:

It is necessary to dissolve 20 - 50 ml of vaseline (medical) oil in 950 ml of extraction gasoline. After you need to mix thoroughly and pour into a bottle.

Composition for cleaning silver contacts:

If it is possible to remove the contacts and place them in a solution, then here's what you can use:

The contacts are first degreased by washing in trichlorethylene, ether or carbon tetrachloride. Degreased contacts are immersed in a bath of 5% potassium cyanide solution (BE VERY CAREFUL THIS IS A POISON!!!). Contacts immersed in the solution (no more than 1 min) are recommended to move the parts. If during this time the dark layer on the silver contacts does not dissolve, you need to immerse the parts in a new solution (the previous one is already saturated).

When the contamination disappears, the silver contact must be rinsed well in running water.

Please note that after such removal, silver is very susceptible to new oxidation! Therefore, your contacts must be placed in a composition of concentrated (25% pure) ammonia solution, for no more than 3 minutes (stir the composition continuously). Then it is necessary to rinse well with running water, or in ethyl alcohol denatured with gasoline or ether and dry well.

After such an operation, the silver contacts will no longer be oxidized under the influence of the external environment.

Recipe for contact protection:

If you need to “preserve” electrical contacts for a long time, then do the following: Dissolve 10-30 g of stearic acid and 980 ml of trichlorethylene in a porcelain cup with low heat (tetrachlorethylene or tetrachlorethylene can also be used instead of trichlorethylene.).

It is necessary to allow the solution to settle and pour into a bottle with a good stopper. This solution has a protective "preserving" effect. Such a solution must be applied to thoroughly cleaned, degreased and dry contacts in a uniform layer.

P.S.: I tried to clearly show and describe not tricky tips. I hope that at least something will be useful to you. But this is not all that is possible to invent, so go ahead and study the site

Aerosol composition of combined action. Removes metal oxides and grease in a single process. Restores electrical conductivity, blocks leakage currents. Does not damage parts made of metals and plastics. - Cleans dirty contacts - Loosens and removes oxide salts - Reduces contact resistance - Silicone-free Using Kontaktreiniger allows you to quickly and easily clean contacts from oxides and dirt, saves time and improves the quality of electrical equipment maintenance work.

Application

Disconnect contacts from power source. Spray the product on the contacts and, depending on the level of contamination, leave for approx. 5-10 minutes. Remove dirt with a cloth, brush or compressed air. If the product gets on lacquer or plastic surfaces, wipe them with a damp cloth. After cleaning, protect contacts with Elektronik-Spray (art. 3110) or LM 40 Multi-Funktions-Spray (art. 3390). Note: connect to the power source 10 minutes after cleaning is completed.