Novice here needs help/advice!

Discussion in 'General Electronics Chat' started by cornflakes, Sep 20, 2012.

  1. cornflakes

    Thread Starter New Member

    Sep 20, 2012
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    0
    I'm not really sure where to ask this question and I found this forum and thought it might fit in.

    I own some cool electronic devices and one of them is my "spy watch". I learned how to desolder/solder the battery wires with success but I've come across a new issue that I don't know how to deal with.

    If any of you might be familiar with spy watches, they have a couple buttons (knobs) on the side of the watches that are for ON/OFF and MODE switch.

    It's very simple to operate. All you need to do is push the knob and hold for 2 seconds to TURN ON the device (indicated by a blue led light). Then you press it again ONCE (no hold) to begin recording. To stop recording, you press it again ONCE (no hold) and the blue light comes back on in standby. To turn off the device, you push the knob and HOLD again for 2 seconds and it blinks red as it shuts off.

    Now normally when I push the knob, it makes a small click sound (the internal button "clicks") and you can also feel the little click of the button. But recently the button stopped making the CLICK sound even though the button/knob still works (device still works). I opened it to take a look because usually it just means that that external button/knob and the actual internal button on the circuit board got moved and was misaligned.

    But this time it wasn't the case. When I pushed the REAL button that's attached to the circuit board (LINKS TO PICS ATTACHED below), there was no click sound/feel to it. It kind of feels a little "stiff" and so the problem is that the button may always be "activating" the device or close to it even if I don't push the button anymore.

    In other words, I found my watch was turning on by itself when I just moved around. Or sometimes while recording, it would stop or shut off, as if someone had held the button for 2 seconds. I'm thinking that the absence of that click sound/feel means the button is jammed or stiffened. So it tends to activate and deactivate my device at any time without my doing whenever I move around.

    I'm trying to figure out if there's a way to fix that button (like some sort of lubricant?) or if I can actually remove that button and solder on a new one? I have spare parts. The device works fine which is why I would like not to have to discard the whole gadget simply due to one button that seems to be either stiffened/jammed or loose?

    Can you take a look at the pics I've uploaded and give me your assessment on it? Does it appear to be something I can remove from the board and reattach working button? Or is that not possible/difficult for me to do with an average soldering kit? Is there perhaps a way to actually OPEN that button (but it's really small) and fix whatever is wrong inside it? Or should I try using a lubricant?

    http://i47.tinypic.com/10moens.jpg
    http://i47.tinypic.com/28l5jm0.jpg

    Help! And thank you!
     
  2. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
    363
    You need to test the tactile switch on the circuit board without interference from the external actuator. If the switch is good then the matter is all PCB mounting/alignment and actuator function. If the switch is bad, it can be replaced but it's not easy on a high density double-sided PCB.
     
  3. BSomer

    Member

    Dec 28, 2011
    433
    106
    Switches wear out over time, some sooner than others. The lubrication idea most likely will do nothing for the switch. These can be somewhat easily replaced though. Before you attempt to remove the old ones, get some measurement of them and try to find a replacement at Mouser or DigiKey. Use the parametric searches to look for a tactile switch that is right angle surface mount.

    To remove them you can use some solder wick and a soldering iron with a small tip to remove the solder. To make it easier you can use a really sharp x-acto type hobby knife or small side cutters to cut the switch off the board leaving the solder tabs in place then use the solder wick. This second method has to be done very carefully so as to not damage the PCB traces or any other components around the switches.

    Once the old one is removed, just solder on your new one using a small tip soldering iron and fine solder. I don't know if this is in your "average soldering kit". Perhaps show us what you do have on hand for your soldering and we can go from there.
     
  4. cornflakes

    Thread Starter New Member

    Sep 20, 2012
    6
    0
    I'll be away for a couple days but when I get home I'll post a picture of my soldering kit. I think it may be too big for this tiny piece? I haven't been able to find a smaller more pinpoint soldering iron than the one i have (which I believe is the standard size if such a thing exists).

    So there's no way to fix the "clicking sound/feel" of the switch when pushed? The other switch still makes the clicking sound/feel when I press it. Is there some way to actually open the switch? (although it looks extremely small for me to do that....wish I had nano hands when working on such tiny parts).
     
  5. cornflakes

    Thread Starter New Member

    Sep 20, 2012
    6
    0
    I did some researching and i found the name of what I'm trying to describe.

    It's called a 'tactile switch' or 'tactile switch surface mount'. I found some to have the exact same appearance as the one on mine. They were for sale for about a quarter to fifty cents each. So I guess this means I can remove the old one and solder on a new one?
     
  6. BSomer

    Member

    Dec 28, 2011
    433
    106
    I did mention that it is a tactile switch in my earlier post... :)

    Yes this is replaceable and fairly simple to do. Just a little patience and the job is done. I would recommend a soldering iron or "pencil" iron that is around 15 - 25 Watts. You can usually get some decent fine point tips for those types. I also recommend using the smallest diameter solder you can find. You can easily get too much solder on the joints when using solder that is thick which can cause "solder bridges" shorting out stuff.
     
  7. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
    363
    Corn, have you read the responses to your original post (it is the traditional method on forums) or are your questions a part of a rhetorical monologue? This was the first response you received (bold added), coincidentally by me.

     
  8. cornflakes

    Thread Starter New Member

    Sep 20, 2012
    6
    0
    Yes, but I'm not too sure what that meant. As I mentioned I'm a novice when it comes to these things. I just started learning how to solder on my own recently.

    I'm not sure how to answer your question. I believe the switch is still good because when I press it, it does activate the device and it does turn off the device also. So it's not like the switch is not working.

    However, this being said, I tried to explain that the switch has lost the "click sound/feel" that you get when you press it. As a result, I can't tell if the device got powered on or not without actually looking at it for the LED light indicator since there is no click sound/feel.

    The other thing is that the device seems to be turning on and off by itself without me pressing the switch. So I think it might have something to do with the lost click sound/feel that is causing the switch to always be in contact or is sensitive to movement so it will constantly activate or deactivate the device without me pushing the button.

    So I was wondering if there was a way to just fix the "switch"...like open it open up and try to re-adjust whatever might be misaligned inside...or if that is too difficult due to the switch being so tiny, is it just easier to remove the switch and replace it with an exact duplicate switch (I have a spare part on the side that is the exact same switch).

    It's kinda hard for me to explain but I hope I got my issue across. I appreciate everyone's advice and I'll try my best to do what I can with it with my limited knowledge and experience with soldering, PCBs, and tactile switches.
     
  9. cornflakes

    Thread Starter New Member

    Sep 20, 2012
    6
    0
    Here is also the pic I've uploaded of my soldering iron place beside the tactile switch....will that work or is there some kind of special "mini" soldering iron i need to buy?

    The 2nd pic shows a couple rubberish looking knobs on the underside of the PCB where the tactile switch is soldered onto. Both switches have those 2 white rubber looking knobs so I assume they belong to the tactile switch? Am I supposed to push them in with some pin to release the tactile switch from the PCB or just ignore those rubber looking buttons?

    http://i45.tinypic.com/j14idt.jpg
    http://i49.tinypic.com/66dx93.jpg
     
  10. joejoenikk

    New Member

    Nov 23, 2011
    9
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    In my experience..... (Double sided PCB means a circuit board that and is nearly impossible to locate the schematic's parts on, ridiculous to trace through with a meter, normal meter probes wont fit on anything on it without shorting out and frying something, requires acess to both sides.)
    ....and I am an unemployed micro brain surgeon with a potential future at a minimum wage job fixing Hillary Clinton's board of education.....

    Your spy watch is responding to the remote phone signals intended for your operation of it, I assume you purchased the watch second hand through the usual shady operative.(I usually take the precaution of wearing a paper bag over my head for such business, if for no other reason, so I can tell the unelected assistant state prosecutor "I don't know what anyone else looks like and if you don't believe me, you and you cousins the under cover cops, can get your own paper bags.") If you had purchased it directly from command central, they would have provided as conviently self destructing message containing the instructions for the remote operator.

    As that is the case, you can be certain that the very expert and shady "Digital remote microwave controll system's guidance" DRMCSG will cause your watch to explode causing great mayhem, and at the most inconvenient time, such as when you are finishing up in the men's room.

    I'm not going to invest onto tools for working on types of devices that noone intended to be repaired and wouldnt recommend it to anybody else who thinks there will ever be money in electronic watch repair, but the device' manufacturer probably already made that investment, so try asking him. If I can't find a schematic and factorry information for a device, then I assume nobody else has a use or parts for one either. As far as the impending explosion, that is what taltium capacitors do best, so try to learn to type with one hand while looking at the keyboard like the rest of us.


    This message will not self destruct, but I am using a vage identity referance, didn sleep in a very closed, seedy motel last night and actually do have a second cousin named Vito.
     
  11. BSomer

    Member

    Dec 28, 2011
    433
    106
    Those "rubberish looking knobs" are just a part of the switch that helps hold it in place during manufacturing so it doesn't move around when placing all the components on the board.

    If the device is turning on/off by itself the switch could have something broken on the inside of it making intermittent contact. This could also explain the loss of the clicking feel and sound.

    It would be better to replace the switch as there really is no way to reliably take apart the switch and fix it.

    Your soldering iron is a little big for this job, but should work fine. You just don't want to hold it on the board/parts too long when soldering or de-soldering because you may damage other parts in the area.
     
  12. joejoenikk

    New Member

    Nov 23, 2011
    9
    0
    Oh, Corlakes, I checked with my Cousin Vito and he said that he is out of ballpeen hammers and that the boys at BHPHOTOVIDEO have your number. You had better kkep your fingers where they are supposed to be untill you check wit them. They got a used one for $45.(Micro test leads and a low capacitance O Scope probe would cost five-twenty times that much.)


    A Watch sized Video camera for less than a hundred bucks? And I'm working out of a PO box on Florida Swampland.

    I'v had great luck doing buisness with them, try to be polite with their girl at the Customer sevice, their whole service departmant is wonderful.

    http://www.bhphotovideo.com/c/produ..._AN_WPWDVR_Waterproof_Spy_Watch_Recorder.html


    BTW anybody ever tried to repair a good quality mechanical watch? It involves an electronc machine that times the "beat" of the mainspring. I tried to get my oscilliscope to do the same thing, but couldnt get enough signal out of my mike amp. If I built a better amp would it work? (TAG HEUER---EVA movement.)
     
  13. cornflakes

    Thread Starter New Member

    Sep 20, 2012
    6
    0
    Thanks for the replies. I think you're right. The tactile switch has something inside that is probably loose which is why the click sound+feel is gone and its intermittently making contact causing device to self power on and off at times.

    It seems that the only thing I can do now is to remove the switch and try to successfully solder on the replacement switch.

    From my pics uploaded, are you able to tell how many points of soldering contact there are? I think its 4, am i correct? (one on each corner).
     
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