Entertainment Center: TVs, Stereos, VCRs and DVDs - RCA TV keeps turning itself off/on

Hello everyone,

I have a problem that has been driving me crazy and need your help with.

I have a 36-inch RCA TV that is about six years old. The model number is F35760MB. For the last few months the TV has been turning itself off and back on sometimes three times an hour, other times once an hour. There is no real pattern.

Then I found a specific channel that would cause the TV to turn itself off/on consistently. It is the internal condominium association channel that comes thru the cable system. If you tune to that channel or move up or down thru it, either with the remote or at the TV set, the condition occurs. If I unplug the cable connection, then tuning pass this channel (which then shows snow) is fine.

So any channel that we are watching can turn off and immediately back on at any time or tuning pass one specific channel can also create the problem. This is annoying!

I have noticed that the picture will go out first and then in about half a second or a little less the sound goes off, and then in about another half second the TV turns itself back on.

I have unplugged the TV from the wall overnight as suggested by RCA. The RCA troubleshooting website states this happens when there has been an electric surge and the automatic electronic protection circuit may have been activated. However, I don’t think this is the problem. I have installed a number of very sensitive surge protectors for both the power and the cable connection with no luck.

I wonder if the problem is with the electronic protection circuit itself that might have gone bad or if there is a general circuit board problem or if there is a remote problem (a brand new RCA replacement remote I bought four months ago stopped working but the Universal remote still works).

I found a website that sells the following parts for the TV but I don’t know which one I should buy and install.

Integrated ckt
Transistor
Transmitter
Circuit
Capacitor
Transformer HV
CTC179DL2

HELP!!!

A few years ago RCA was having problems with the CPU’s in their TV’s being affected by the collapsing magnetic field around the CRT. The fix was a small metal shield covering the CPU and soldered to ground. Also do you have any bright light sources around the TV? Bright lights can effect the operation of the infrared pickup. Other than that the transformer could be failing or a capacitor somewhere failing. Numerous things can cause this. But since it’s happening all the time it should be easy to find by someone that knows what they are doing…

Problem solved!

It turned out to be the High Voltage regulator. After conducting post by post search on the entire forum, I found the post appearing below that hinted at the problem. Smokey was right on the money on this one.

As soon as i reduced the brightness level a little bit, the problem got solved. So HV regulator might be on its last days. At least now I know what to purchase when it finally goes.

Thought about posting the info below for future people in similar situation needing additional info.

Here it is.

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Hi: This is Gary, I have a 1992 mitubishi ( can"t spell) 35 inch direct view. (tube type) When the t.v. is on , an i adjust the sharp,brightness,color to the high setting"s the T.v will turn off. No the remote. When is want a real sharp an fairly bright picture it will turn off. when i back down those setting"s the tv will stay on. Will run all day long.

Thank"s Gary
P.s just found your website. Great site



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08-18-01 07:34 PM



Smokey
Moderator

Registered: Dec 1999
Location: The Great State of Tennessee
Posts: 2961

Good Afternoon, Gary:

Welcome to DoItYourself.com. I regard each new post as a new friend and will do my best to help you through your problems.

Mitsubishi (Japanese: Me-Ta-Sue-Bee-She) is an excellent set and is well respected in the electronic community for workmanship.

However, I feel you have a failure in the high voltage regulator circuit on your set. (Even the Swiss have a bad wristwatch now and then). At lower brightness levels, the picture appears out of focus and things are not distinct. Right? When you advance the brightness and contract controls, things get sharp and distinct?

Let's talk about high voltage circuits for a second. It takes a voltage anywhere between 25,000 and 45,000 volts to the screen of your TV picture tube to allow the tube to make a picture. This voltage has to remain constant so that the picture does not change during scenes of darkness and scenes that appear in high brightness. So, the manufacturer puts in a a regulator circuit to ensure this voltage stays at the same level. When the regulator circuit fails (and they do!...now and then), you have to adjust the brightness and contract to a level where the voltage is optimum to get a decent picture.
Another note is the fact that the high voltage circuit provides a "focus" voltage to the picture tube and any change in the high voltage causes this focus voltage to change.

Shutting off? Well, that is protection circuit provided by the manufacturer. If the high voltage regulation is removed, the high voltage can reach values outside of the safe parameters. When it does, the set is designed to shut off. It saves you from damage to the TV as well as fires.

Call your repair shop and discuss what I have given you for information.

Have a good day and be kind to one another.

Smokey