Sound but no picture, picture returns after switch off/on.

[[email protected]]

Hi,

Akai 28in Wide Screen.
After a few minutes the picture goes black, I have sound but no
picture.
Switching it off then on again fixes it for a little while then the
picture goes off again. Could last hours or go off in 2 minutes.
Any ideas?

Alan

 

[Jerry G.]

It can be a temperature related problem, where a component is working
on the edge of spec. When powering the set down, and up again, the
specs are changing enough to allow the set to start.

To resolve this, proper troubleshooting of the power supply, scan
circuits, and related areas would have to be done. This is something
you would not be able to do at home, unless you have experience in TV
servicing, and are set up to do this type of job.

Jerry G.
======

 

[Newfdog]

Hi,

Akai 28in Wide Screen.
After a few minutes the picture goes black, I have sound but no
picture.
Switching it off then on again fixes it for a little while then the
picture goes off again. Could last hours or go off in 2 minutes.
Any ideas?

Alan

check the picture tube heater elements to see if they are glowing. If
not you probably have a bad connection on the crt neck.

 

[[email protected]]

Thanks for your replies.
I originally thought that the problem was of the usual dry solder
joint type but now I'm not so sure.

Switching the TV off and on using the standby buttontakes less than a
quarter of a second and it always fixes the picture if only for a
little while. I wouldn't expect this if it was a problem with heat
expansion of a circuit board. Also the room temperature doesn't seem
to make any difference. The connector at the neck of the tube still
glows when the tube has gone off.

I don't know too much about electronics, I'm a former electrician so I
have a grasp of the basics but could it be something to do with a part
of a circuit discharging when the picture is switched off? Or voltage
regulation perhaps? I told you I don't know too much electronics!

I had hoped that the fault would be of a type that someone would
recognise as a particular one.
Otherwise I will have to take Jerry G's advice and take it to a
repairer.