Panasonic PL1 switching channel by itself

[terminus]

I have a Panasonic PL1 which has started switching channel from AV1 to analogue by itself. It's been happening for a couple of weeks now. Sometimes it flips back and forth rapidly and other times it will just go to analogue and stay there. Pressing AV on the remote a couple of times usually stops the rapid switching but the problem keeps coming back (it happens most days).

Can anyone tell me how serious the problem is and the potential cost of repair?

Thanks in advance.

[JayCee]

The no1 suspect is a loose scart lead in the AV1 socket.

[terminus]

Thanks for the quicky reply JayCee. I didn't realise that loose scarts can cause TV/AV switching. I checked the scarts and they seemed securely fixed. I pulled them out and put them back (at the TV end and then the cable box) and noticed that the set remains in AV mode rather than switching to TV mode. Just thought that might be useful point.

[JayCee]

If the device (in your case your cable box) is active (switched on) and you plug it in to your TV the TV will switch to whatever AV input the scart is plugged in to...if you then switch the cable box to standby the TV should switch back to it's internal tuner.

[Adge13]

what appears on the screen AV1 or EC1 ?
If its EC1 then pin 8 on the scart socket has gone high ( 5volts )
AV1 is a manual switching to the scart input. if pin 8 does go low ( 0 volts ) as if the source goes off the tv will remain on the AV1 input .
EC1 is auto switching from the source .
A question - Do you have any energy saving light bulbs being used in the same room ? If so they do give off IR info to do strange things to av units when turned on !!!

[terminus]

Adge13,

99% of the time to TV is manually set to AV1. This is because I only watch the cable source except for occasionally switching to analogue to view Teletext. Yes I see what you mean, auto switching only works in TV mode when it detects a signal change, when it is manually set to AV it doesn't switch to the internal tuner if the source is cut, instead the screen goes blank.

So to clarify the fault occurs when the TV is in AV1 mode and it switches between AV1 and the internal tuner as it would if you rapidly pressed TV/AV on the remote. Pressing TV/AV on the remote can stop the rapid switching.

Yes the room has had energy saving bulbs for a long time, what an interesting point. But I've had the TV for 9 months and I've only noticed this problem during the last two weeks.

[Chris Muriel]

Energy saving bulbs contain electronics (an inverter) which could perhaps have developed a fault within the last 2 weeks; switching them (all) off temporarily should indicate whether or not they are the culprit.

Chris Muriel, Manchester

[Adge13]

If the fault does not go away try removing the batteries in the remote to see if it's transmitting incorrectly . You could also try putting the TV in shipping mode by the menu , this will reset the TV and will then go into Auto tune mode . If that does not work you could go into factory reset .
I did have a TV changing channels when ES light bulbs are used .

[terminus]

Thanks everyone for your input. I'm relieved that no one is suggesting an internal fault.

I will try your suggestions and I'll also keep an eye on the TV remote sensor light next time it happens.