Hi, I have a Toshiba 28W8DBA widescreen television about 6 years old which has developed a green tint to the picture.
It's even noticeable on blank black backgrounds and I would like to have a go at fixing the problem. Has anyone got any experience of this model and any hints as to where to start please?
Am I right in saying it's a CRT TV? If so this is very common. The tube is aging and the red gun is losing output.
CRT sets usually have two sets of controls to adjust the colour balance - foreground (whites) and background (blacks). Again, the background changing before the foreground is common with age.
At one time there would be internal pre-sets to adjust this balance called grey scale adjustment. On newer sets it is usually software controlled via an engineering menu. How you get into it on your set I've no idea. A Google on that might help.
The tube has gone. I had this exact same TV, at 4 years and 10 months it developed the same problem. As it was still 2 months within warranty I git them in to fix it and they replaced the tube. I had to wait quite a while for a replacement but it was as good as new when done. I would guess it's not really economical to repair if you have to pay for repairs yourself.
If it's a green *tint* then it should be adjustable. As I said all tubes age, and the red gun losing emissions is the first sign. Trinitron tubes are notorious for it.
If, however, there is no red at all then the tube might well have failed. But the Op suggested the 'whites. are ok - only the 'blacks' showing the problem.
In message , Colin Wilson writes
I typed a few model numbers in - they all cost
In message , "Dave Plowman (News)" writes
Thanks Dave, it is a CRT. You inadvertently solved the problem. Your comments gave me something to track down i.e. Service Menus and I found:
It is ageing of the tube as you and others suggested and I managed to cure the problem in 5 minutes using Steve Larkins' notes so thanks one and all.
Just to say even although it is aging it could last for many more years with just the occasional adjustment.
Since the whites are fine but the _blacks_ are tinted, its clearly not a tube problem, but a video drive issue.
The OP would do well to ask an electronics group, eg sci.electronics.repair. This is a DIY group, ask about electronics at your peril.
NT
You've not read the replies, then, and the satisfactory outcome?
And you're just about as likely to get an answer about such general things here as anywhere else.
In message , "Dave Plowman (News)" writes
You are right Dave. I have found this group extremely useful over the years, mainly as a lurker but, in my case, I have had 2 definite results in the last week alone.
At least you get practical suggestions without all the science, unless you want it of course!
TV's still working well.
I also have a Toshiba CRT TV of this series, but not this model, that has tended towards a muddy green colour on blacks for a while.
A tweak to the green cut off and a little to the red has fixed it very effectively.
I was aware that there was an incantation to get into the engineering menu but had never bothered to look for it (lack of tuits). Having read this article, it became annoying so I had to fix it.
I know who knows about electronics here, who knows about RF stuff, who knows about audio, who knows about cleaning machines and so on.
In almost all cases, the suggestions are good.
Indeed. You may well get more answers on one of the specialist groups but that usually means more wrong answers too.
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