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Other Vintage Household Electrical or Electromechanical Items For discussions about other vintage (over 25 years old) electrical and electromechanical household items. See the sticky thread for details. |
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23rd Jan 2019, 8:33 am | #1 |
Dekatron
Join Date: May 2006
Location: Invercargill, New Zealand
Posts: 3,440
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Cheap 1980s clock radio buttons
Two things straight up.
Firstly, this thing is 31 years old - a Christmas present from my parents in 1987 - so although it doesn't seem vintage, it seems to fit the definition. Secondly, I think I already know the answer to the question - it's knackered. With that out of the way, I have a "Pro Series" clock/radio/cassette - although I never used the cassette section, and it literally fell apart within five years. Pro Series was David Reid Electronics' home brand, and was basically cheap rubbish. My problem is with the buttons. They are similar to the rubber ones in remotes - some traces on a PCB with a conductive pad that pushes against them. The conductive pad is on a "stalk" from the buttons at the top, with a rubbery surround. About seven or eight years ago the unit started doing some weird things with skipping blocks of time and button-presses were unreliable, so I cleaned them up and it was reliable-ish since then - until the last couple of months that is. It's now at the point where I struggle to set the time - it picks up random button presses, no button presses, and is generally unreliable. I've disassembled, cleaned - no difference. My suspicion is that the rubbery thingies have lost all their flexibility - they just aren't lifting the conductive pads up high enough to stop phantom button-presses. So, question - can anyone think of anything that could get me a little more? I know that this was a cheap clock/radio, and that 31 years would be a good run even if it wasn't a cheapie, but because it has just lasted so long I want to explore options. Funnily enough if it died 20 years ago I'd probably have just gotten rid of it without thinking! The other thing is that the light qualities of the red LEDs from this era seems far less harsh and obnoxious than more recent ones that I've seen at hotels/motels - even when they are red they seem quite harsh in comparison. Thoughts? |
23rd Jan 2019, 8:52 am | #2 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
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Re: Cheap 1980s clock radio buttons
With a bit of ingenuity, you might be able to solder "tact switches" to the PCB, discard the rubbery things, and adjust the buttons so they operate the new switches.
http://sc02.alicdn.com/kf/HTB1R5uORV...-12VDC-SMD.jpg Nick/ |
23rd Jan 2019, 8:55 am | #3 |
Hexode
Join Date: Oct 2010
Location: Sandiway, Cheshire, UK.
Posts: 323
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Re: Cheap 1980s clock radio buttons
I repaired an original Sony TV remote where the buttons had become unreliable by gluing a tact switch on the board and connecting them with fine wire to the pins of the chip. The board tracks were carbon ink (or whatever they use) and obviously could not be soldered to so I could not just attach the switch as if it was surface mount. Your PCB looks conventional so its just a matter of finding a suitable switch and soldering it in position.
I used through hole switches an folded the legs flat, but you might find a surface mount one that suits. It took me a while to replace about 12 of the most worn switches and trim some of the rubber away (to allow for the switch height) but the repair is permanent and the remote controls is much better to use as the replaced buttons have a proper feel to them and click. Ian |
23rd Jan 2019, 9:42 am | #4 |
Dekatron
Join Date: Jun 2009
Location: Staffordshire Moorlands, UK.
Posts: 5,263
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Re: Cheap 1980s clock radio buttons
I agree with nick n phil, mini tact switches. Little surface mount ones designed for mobile phones will fit in there if you file a bit of the copper pads away. You might need to cut a bit of the rubber actuators away to get the height right.
I've done it myself, you need a fairly light-force switch. I've used these https://uk.farnell.com/c-k-component...=tact%20switch
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Kevin |
23rd Jan 2019, 11:16 am | #5 |
Octode
Join Date: Sep 2004
Location: St. Albans, Hertfordshire, UK.
Posts: 1,477
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Re: Cheap 1980s clock radio buttons
If you can't find anything locally, I have a number of these things I could pop in the post for you. They are replacement inserts designed to fit some test equipment panels, but would almost certainly do the job.
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Regards, Richard, BVWS member |
23rd Jan 2019, 11:56 am | #6 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,787
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Re: Cheap 1980s clock radio buttons
You could try cleaning all the mating surfaces, assuming you haven't done that already.
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23rd Jan 2019, 12:20 pm | #7 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
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Re: Cheap 1980s clock radio buttons
You could, but it does sound like the rubber domes have collapsed, leaving the conductive pads almost touching the PCB tracks when the button isn't being pressed.
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23rd Jan 2019, 1:08 pm | #8 |
Moderator
Join Date: Jun 2003
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Posts: 27,787
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Re: Cheap 1980s clock radio buttons
I completely agree, but it's always worth trying the quick and simple things first.
One oddball thing to try is to boil the domes in an old saucepan for a few minutes. If you're lucky this will restore their 'rubberiness', though it will depend on the materials used, and there's a risk they'll just melt. |
23rd Jan 2019, 8:11 pm | #9 |
Nonode
Join Date: Jan 2016
Location: Stafford, Staffs. UK.
Posts: 2,529
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Re: Cheap 1980s clock radio buttons
If size is an issue it's possible to get really small tact switches as used on the PCBs of car key fobs. They are sold in various places for repairing car keys. They have solder pads in the centreline of the body, rather than at the corners as with many tact switches so would probably make life easier with your PCB.
But bear in mind it could be something else. The switches will be pulling a line up or down and it will likely have a resistor somewhere to soft pull it the other way. So, for example, if the input to the micro is normally pulled high by a resistor, and the switch pulls it low then if the pull up voltage is too low it will look like the switch is pressed when it isn't. |
24th Jan 2019, 12:32 am | #10 | ||
Dekatron
Join Date: May 2006
Location: Invercargill, New Zealand
Posts: 3,440
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Re: Cheap 1980s clock radio buttons
Thanks everyone - I had thought of tact switches, I have a drawer full of pulls from some old VCRs which may work, or element14 have a good range. I may end up getting some resistance from my wife about this, but may end up giving that a go. I will need to shorten the shafts from the buttons, but I haven't really got anything to lose with this one.
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I know what I'm going to try - either this weekend, or next time I've got a large enough order from element14 to get free shipping on some 50 cent switches like the ones Kevin suggested |
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24th Jan 2019, 6:38 pm | #11 |
Nonode
Join Date: Jan 2016
Location: Stafford, Staffs. UK.
Posts: 2,529
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Re: Cheap 1980s clock radio buttons
Another thought. Many many things have those rubber dome switches. You could chop one of those mats up leaving enough excess around the edge to fix to the PCB. Go for one with gold pills inside.
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24th Jan 2019, 7:02 pm | #12 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,787
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Re: Cheap 1980s clock radio buttons
Yes, you may be able to scavenge something from an old remote control or pocket calculator.
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17th Jul 2019, 2:49 am | #13 |
Dekatron
Join Date: May 2006
Location: Invercargill, New Zealand
Posts: 3,440
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Re: Cheap 1980s clock radio buttons
An update on this - I kept putting up with it, until an over-enthusisatic cat jumped on top of it, and made it virtually unusable...
I ended up using some tact switches I scavenged from an old VCR years ago, one of a pile I was scrapping to get the VHF system B modulators for Kat who was a member here years ago. I just needed to cut down the plastic actuators a little - fortunately it was a relatively soft plastic, so I just carefully used mini side cutters until they were all the right length. I now have a perfectly working clock/radio. It should be good for another 31 years! |
17th Jul 2019, 7:46 am | #14 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
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Re: Cheap 1980s clock radio buttons
Well done, looks like a neat job.
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