Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default RCA TV(s) Turns Itself On and Off

Hi,
I am a retired consumer electronics repair tech.

Recently, my 14" RCA, (CRT) model 14F512T (mfg. 2006) began turning
itself on, then off.

I remember years ago, I had the same issue with a 27" RCA (CRT) model
27V412T doing the exact same thing. I discovered that the on/off power button
switch on the front panel was the cause. Even though the button switch
checked AOK (no "leakage current" between the contacts using a 50V leak test),
I decided to open the circuit so the switch is "disabled". That fixed the
problem. Note: Remote turns the TV on/off.

I did the same thing with my 14" RCA TV, and that fixed the problem.

John

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Default RCA TV(s) Turns Itself On and Off

Hold on - first question :

Does it turn itself on with no intervention or do you turn it on and then it turns off and then back on ?

This is an important question.
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Default RCA TV(s) Turns Itself On and Off

On Sunday, 10 June 2018 04:44:44 UTC+1, wrote:
Hold on - first question :

Does it turn itself on with no intervention or do you turn it on and then it turns off and then back on ?

This is an important question.


TVs like that have been buried in their millions here. You can't give them away.


NT

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Default RCA TV(s) Turns Itself On and Off

Hi,

This TV, located in the basement, is connected to a power strip with a
switch that "disconnects" everything that is plugged into the power strip.

I normally keep the power strip switch in OFF position. Recently, when
I turned it on (power strip), not long afterwards, the TV started to turn
itself on, then off. Then it repeated that "activity".

John


On Sat, 9 Jun 2018 20:44:42 -0700 (PDT), wrote:

Hold on - first question :

Does it turn itself on with no intervention or do you turn it on and then it turns off and then back on ?

This is an important question.




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Default RCA TV(s) Turns Itself On and Off

On Sunday, June 10, 2018 at 1:07:02 PM UTC-5, wrote:
Hi,

This TV, located in the basement, is connected to a power strip with a
switch that "disconnects" everything that is plugged into the power strip..

I normally keep the power strip switch in OFF position. Recently, when
I turned it on (power strip), not long afterwards, the TV started to turn
itself on, then off. Then it repeated that "activity".

John


On Sat, 9 Jun 2018 20:44:42 -0700 (PDT), ...


OK, there are a million things that can turn it off but few that can turn it on. You might have bad little suppression caps or diodes at the keypad on the unit. They get intermittently leaky and can cause this. One way to find out is to power the unit up with the keypad disconnected. If it still comes on by itself it is either noise in the IR receiver or a bad uProcessor.

In many newer sets the keypad and IR receiver are on the same board and disconnecting one also disconnects the other rendering the test only conclusive to prove the uProcessor is good - if the behavior stops, though the caps and diodes may be on the main board in which case it is more logical to eliminate the noisy IR receiver first. To do this you'll have to unsolder it and remove it, and see what happens of course.

An IR receiver causing this is not unheard of but is a bit rare. It depends on how they structured the pulse trains in the system.

Assuming it does not stop without the IR input, you can remove those caps and diodes, lift one end unless they are SMD. When they are removed observe static handling methods, touch the unit before operating anything on it as it will be vulnerable. But if the behavior stops all you need is diodes and caps. Actually though it could be the glue underneath, but to prove it you pretty much ruin the components anyway so, you need them.

Unless the uProcessor is bad. That is pretty much a death knell for those things. It is unlikely you can get one and who knows, it might be BGA which quite frankly is not worth the trouble to change. They give away working TVs on Craigslist. I am only here because I firmly believe that anything that does not go to the dumpster is good for us and good for our country. It is worth a try unless one is too busy.
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Default RCA TV(s) Turns Itself On and Off



This TV, located in the basement, is connected to a power strip with a
switch that "disconnects" everything that is plugged into the power strip.


is it damp in the basement?

leave the TV on for 10 hours to let it dry out.
mark
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Default RCA TV(s) Turns Itself On and Off

On Tuesday, June 12, 2018 at 1:26:28 PM UTC-4, wrote:

This TV, located in the basement, is connected to a power strip with a
switch that "disconnects" everything that is plugged into the power strip.


is it damp in the basement?

leave the TV on for 10 hours to let it dry out.
mark


Guys, unless I'm reading the OP's post incorrectly, he fixed the TV with new contacts. I think he was just passing along the info and story.

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Default RCA TV(s) Turns Itself On and Off

"Guys, unless I'm reading the OP's post incorrectly, he fixed the TV with new contacts. I think he was just passing along the info and story. "

You're right. But the info applies to new TVs should a similar case come up..

That is unless it uses those capacitive buttons. Whoever decided to use those for this application needs to be boiled in bacon grease. On a pitch black background, and the labels only light up if you touch them, bull****. I want a button protruding and I want tactile feedback. If they can't do that I will keep my 30+ year old TVs and when they no longer get a signal I will break out the VCRs. Actually they are out because there has been practically nothing worth watching produced in the past 25 years. Even the news. Instead of telling us what mischief city council is up to they want to tell us about this new gizmo we can buy. That is not news. Garbage.

Whenever possible I will hep to keep this old stuff running. Any exceptions, yes but they are really complete junk from back when. They were out there..

So it stands. Nobody can delete it anyway. But you are still right.
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Default RCA TV(s) Turns Itself On and Off

On Tue, June 12, 2018 at 7:00PM, wrote:
"Guys, unless I'm reading the OP's post incorrectly, he fixed the TV with new contacts. I think he was just passing along the info and story. "


You're right. But the info applies to new TVs should a similar case come up.

That is unless it uses those capacitive buttons. Whoever decided to use those for
this application needs to be boiled in bacon grease.


Insects roaming in and out of devices aren't any help, either.

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