Greenish tinged pic on Sony Trinitron KV21-XMTU

[matahari]

I have an old Sony Trinitron KV21-XMTU given to me but without a remote or User Manual. Till recently it had a brilliant picture but in Freeview it has now acquired a faint greenish cast and the contrast, brightness and colour are not as clear as when I switch off the freeview and watch analogue.

There are no controls on the Freeview remote to alter the picture. There are some controls on the front of the tv but without a manual I don't know what they are and whether they could alter the picture.

Here they are:

I have tried doing a Reinstall of programmes on the freeview box but it hasn't changed anything. I have also tried wiggling all the various leads - the connection is through my old video recorder.

The picture is what I'd call "flat". I have used the freeview box with a portable Hitachi tv and haven't noticed any loss of picture quality on that.

Can anyone help?

 

[Mickymoody]

Are you watching freeview via scart, and terrestrial from the aerial? might have a dry joint in the scart socket? or a faulty scart lead? Or a faulty bit in the painter chip?

Or might be a stuck electrode in the tube base, thats biassing the other two colours? or a faulty tube, or dry joints in the tube base.

 

[matahari]

Thanks Micky. I think I'll just keep watching it till it gives out. I recently had another problem with it, it kept losing both picture and sound. I had it repaired, the man said something had burnt out which he had cut away. It's since then I have noticed the change in pic quality.

Going to a jumble sale today ... I'll see what's there!

 

[freddiemercurystwin]

Or check out freecycle if you're happy with another CRT, people can't sell them so sometimes just give them away, saves them taking it to the dump.

 

[matahari]

Thanks Freddie, good idea.

But - Would it be possible to alter the picture using the tv controls?

 

[Mickymoody]

Sony of the era that you post the picture of, had tube issues, and you can tap the tube base with a screwdriver to free the electrode that's magnatised itself, but doing so might result in the TV blowing up! The RGB settings can be adjusted, but if the CRT is worn, they never look right, as the other guns overwork.

As suggested a freecycle request would result in a new telly for you.

I recently had a 32" widescreen TV that I couldn't give away...and two 19" monitors, nobody wants them. Can't give them away. So Freecycle is your friend.

 

[matahari]

Thanks everyone, I'll put a request on Freecycle.

 

[IJWS15]

Now that is an old TV - we had one in the late 80s.

Bear in mind that they have a potential fire fault - the on-off circuit can fail and if you don't turn the TV off quicky (at button not by the remote) it self ignites. Wife turned ours off just in time and repair man told us about the issue.

 

[Mickymoody]

Now that is an old TV - we had one in the late 80s.

Bear in mind that they have a potential fire fault - the on-off circuit can fail and if you don't turn the TV off quicky (at button not by the remote) it self ignites. Wife turned ours off just in time and repair man told us about the issue.

I've lost count of the number of carbonised Sony on/off switches I've replaced, more than any other brand, they seemed to go through a bad patch,as Sony were excellent for reliability before and after this period.

 

[matahari]

Thanks guys, I will be on my guard. I NEVER go out of the house and leave an electric appliance switched on (apart from a radio for the Greyhound, if he has been left Home Alone), and at night everything is turned off at the set. I am still living with this old tv. I got a new scart lead for it and that seems to have helped the picture colour - or I might be deluding myself.

 

[Mickymoody]

It's always possible that the scart socket has become dry jointed, so your replacement scart socket temporarily fixed this? Philips monitors were bad for dry jointed scart sockets in their day..

Try 'wiggling' the scart lead connection, to see if there is adjustment, as the RGB signal is sent straight to the tube base, past processing, and they do become dry jointed.

 

[Agile]

Some of the old TVs of that era had pots on the tube base or PCB to adjust the brightness of each colour.

But that fault does not sound like that if its been properly described as it is said to work OK on the RF input.

If thats correct then it would rather oddly be a fault on the video circuit associated with the video input circuitry from the scart lead but NOT in the path from the RF source.

Tony

 

[Mickymoody]

Some of the old TVs of that era had pots on the tube base or PCB to adjust the brightness of each colour.

But that fault does not sound like that if its been properly described as it is said to work OK on the RF input.

If thats correct then it would rather oddly be a fault on the video circuit associated with the video input circuitry from the scart lead but NOT in the path from the RF source.

Tony

Oh heeby jeeby Tony! Sony TV of this era were renowned for CRT jams, and hitting the CRT base SOMETIMES cleared that fault, mainly temporarily. But not a task to be done by the uninitiated, the CRT is fubar.

To adjust the pots on the tube base, without sine wave generators, scopes etc, is suicide, as the picture will never be the same again. Been there done that! Even WITH the correct equipment! Once a gun is failing, as the CRT has failed, you cannot manually restore it. And Sony, in this era were renowned for it to me. I got donated a very large screen sony, with the same problem, and play as I might, I could not cure the green tint problem. But happily my 20 year old B&Q TV soldiers on quite happily. Lots of pots to expand TV size, within the frame, quality picture still. Look out for them.

 

[Agile]

But that fault does not sound like that if its been properly described as it is said to work OK on the RF input.

If thats correct then it would rather oddly be a fault on the video circuit associated with the video input circuitry from the scart lead but NOT in the path from the RF source.

Tony

You seem to have ignored what he said about working OK on the RF input. That makes me think that its NOT a tube fault but an input/video processing fault.

I never had any suicide from adjusting the colour pots on those old TVs. A simple colour bar generator was useful but I found that if it was set at black level then it was likely to be OK with a picture as long as nothing else had been misaligned.

Tony

 

[Mickymoody]

But that fault does not sound like that if its been properly described as it is said to work OK on the RF input.

If thats correct then it would rather oddly be a fault on the video circuit associated with the video input circuitry from the scart lead but NOT in the path from the RF source.

Tony

You seem to have ignored what he said about working OK on the RF input. That makes me think that its NOT a tube fault but an input/video processing fault.

I never had any suicide from adjusting the colour pots on those old TVs. A simple colour bar generator was useful but I found that if it was set at black level then it was likely to be OK with a picture as long as nothing else had been misaligned.

Tony

I don't think I have ignored the OP regarding an RF fault Tony? I directly refer to it in two of my posts above, and I don't think the OP makes it clear that there is no green screen fault when watching via RF, just that the contrast and brightness aren't as good when watching via RF, which is to be expected. But it's a TV that isn't worth anything, people throw away better, hence why the OP was referred to the Freeview website, where good quality stuff is donated daily. If the OP has no experience of repairing this, then not worth taking the back off, even for a looksee.