Toshiba 32ZD09B - black screen fault - help/advice needed!

[danowen79]

I have had a 32" CRT Toshiba (32ZD09B) for about 6 years now and recently the picture has started to go either very dull or psychedilic. Hitting the bottom of the screen, just above the middle internal speaker, seems to "reset" the image back to normal... and you can then go weeks or months before it happens again...

However, just recently the picture has gone totally dead (black with no sound). Hitting the TV didn't work, although the next day the picture came back and all was fine for a few days. But now it has happened a few more times, and this time hitting worked -- but now required more of a WHACK than usual!

One worrying thing is that changing Extensions seems to really mes the picture up! If I change from EXT1 (digital TV) to EXT2 (DVD), the picture goes black and needs a hit to get it back. But, when I get the DVD picture back, there is NO sound. Cycling through Extensions just gives me black screens and a short delay before the picture appears... or otherwise needs another whack to get it going.

Does anybody know exactly what is causing this, if it can be repaired, and how much it would cost approx?

I initially though the tube was going, but is that likely after 6 years? Also, the picture quality when it appears isn't "odd". It seems like the TV just has difficulty "finding" the feeds whenever I change extensions!

Any help/advice would be much appreciated on this! I don't want to dish out on a new TV if this one can be fixed.

Thanks,

Dan

[JayCee]

If mechanical vibration (whacking it) restores the picture...that suggests a dry joint.
Best to call in an engineer and get an estimate.

[danowen79]

Thanks for that. Would you have any idea what the likelihood of fixing a dry joint is? I have never heard of that before, but it seems to fit the symptoms. I thought it was a colour tube issue for months until changing Extensions became the issue this week...

[AnilS]

Dry joint as suggested. Should cost no more than £40.

Mine is also 6 years old but fine (tempts fate )

[danowen79]

I'm glad two people think the same :-) That's reassuring. Out of interest, is the "joint" in question the mechanism that changes the extensions? So it's effectively not quite making the connection and giving me intermittent audio/visual problems?

Just want to understand more about this so I'm armed with information and don't get ripped off!

Dan

[JayCee]

Electronic components (excepting surface mount) are mounted on top of a printed circuit board and connected underneath the board by solder...the solder joints develop a crack or ring around them for various reasons (overheating, mechanical vibration etc) momentarily lose connection and are then known as "Dry Joints"...it is something every TV engineer comes across every working day while working on circuit boards...very obvious ones can be spotted with the naked eye but sometimes the loose connection can only be found by the use of a strong magnifying glass which most good technicians carry with them in their toolcase.
The cure is to clean and remake the component/solder joints.

[danowen79]

Ahhhh, I see. That makes sense. So probably not a good idea to keep hitting the TV then incase the "dry joint" gets worse?

Is this something an engineer could fix quickly on the spot, or would it mean taking the TV away?

Thanks for all the help - great to see people willing to help out. Isn't the internet brilliant! :-)

[JayCee]

Originally Posted by danowen79

Is this something an engineer could fix quickly on the spot, or would it mean taking the TV away?

Most good engineers would have a go at repairing it in your house...removing a set to the workshop is a last resort for a lot of them.
It all depends on whether the fault is obvious.
Good luck.