Hi, It looks like the problem is fixed (see below for details).
This is the first time I have encountered a button switch/s that tested good (no "leakage" at 50V test), but turned out to have intermittent "leakage".
Thanks to everyone who offered their help, Brad
Hi,
>
> I finally found something that may be the cause of this problem. I will
>report back in a week or so after I confirm it.
>
> This was the first test I performed on this TV, which "past the test".
>I used a capacitor tester's "leak" test (very sensitive) set at 50V and
>checked all the button switches. Absolutely no sign of "leakage".
>I won't tell you all the other things I did. Sometimes it pays to re-test.
>
> This time, when the TV started it's off/on "ritual" again, I unplugged the
>TV and I performed another "leak" test on the button switches.
>Wow!!! now I have a "leak" indication. Imagine, an intermittent "leak"!!!
>I opened the circuit trace to all the button switches. Now, I will use the
>remote control on this TV for the next week or so to confirm. Please
>"stay tuned".
> Brad
>
>
>>
>>Hi,
>>
>> PLEASE READ my original post below.
>>
>> I have a RCA TV model 27V412T, chassis M134C (mfg 01/06) back in my shop,
>>which I thought I repaired after I replace the remote receiver. The TV worked
>>fine for a couple days, then it started all over again. I removed the remote
>>receiver and put a 10K from +5 to the remote's output line, but the TV
>>still turns on, then off by itself. I checked for leakage on the panel button
>>switches. Also I found out, before I removed the remote receiver, the TV
>>would not respond to remote commands, and the scope showed a good
>>output signal from the remote receiver. Note: The TV did respond to remote
>>commands when I first started working on it. I checked the +5V and scoped it
>>for noise.
>>
>> I found info on the Web about a setting in the service menu that can cause
>>this problem, via "7", OPTM2 should be at "00", but this setting is correct
>>("00").
>>
>> Did you have a similar problem with this or similar a model TV?
>>
>> Thanks in advance, Brad
>>
>>>>
>>>Hi,
>>>
>>> I have a RCA TV model 27V412T, chassis M134C (mfg 01/06) in my shop
>>>that seems to have a mind of it's own. My customer said this problem got
>>>worse over time (a few weeks). I have Sams Photofact 5234.
>>>
>>> The TV will play for a short time, then turn off, a short time later, it
>>>turns back on, then again it goes off, etc. I checked all solder joints
>>>(AOK).
>>>
>>> HV is 28KV, reg B+ is 130V "run", and 10V in standby.. While the TV
>>>played, flexing the circuit board (removed from it's holder), tapping the
>>>circuit board, using a hot air gun on parts, had no effect.
>>>
>>> I checked electroylitics in primary side of SMPS and reg. B+ (AOK).
>>>I checked voltages on secondary side of SMPS and found a schematic
>>>error for 24V source. I found 24V present at emitter of Q205 used as a
>>>"switch" (one of several) which indicates the 24V source is normal.
>>>
>>> Did anyone encounter a similar problem?
>>>
>>> Thanks in advance, Brad
>>>
>>> Before you type your password, credit card number, etc.,
>>> be sure there is no active keystroke logger (spyware) in your PC.