Sony KV1320 - worn tube???

[AidanLunn]

Originally Posted by Heatercathodeshort

I'll third that. If you fiddle with the purity and covergence adjustments on any Sony models they are very difficult to reset. They were set under very critical limits in the factory. Remove the speakers and enjoy the set as it is. They were only designed for a ten year life and were very sensitive to external magnetic fields. They were not deigned for perfection being just a 13" transportable set giving a very good account of itself in the early days of colour television. J.

IIRC, there was an EU trade law at the time stipulating that no TV made outside of the EU could be above a certain screen size. Others might know differently, but I don't think these was intended as a "portable" colour TV, especially when in the early 70s, a colour TV would usually be the main one in the house, with a b&w portable or previous main TV taking up residence elsewhere in the house. That's just what i presume and I'm open to corrections.

[AidanLunn]

Originally Posted by VideoJunkyard

Firstly, check the degauss circuit (as has already been advised) - there should be a definite loud buzz at switch on. If not then you'll need to check the positor and wiring to the degauss coil - its a very simple circuit.

I'm going to check it myself, but two questions first:

1) How long should I leave the TV switched off for until I perform this check? (this is actually the first time I have ever opened up a TV and to a complete novice like me, no part is safe until proven safe by experts like you lot.)

2) Does the positor look like this: http://www.easyspares.co.uk/image.as...200&height=200

or does it look totally different? (as I've had no experience with something like this, I wouldn't know if positors now looked the same as they did then or not).

[murphyv310]

There were import controls in the early 70's but the max tube size from Japan was 18 inch, hence the Sony 1810UB and 1820UB, of course this changed when the Japs opened up factories in the UK and other EU states, the controls didn't last that long and of course there were plenty of 19 inch and 25 inch British sets.
I also believe that Sony offered a KV1320UB at a discount if you bought an 18 inch set!

[AidanLunn]

If the Sony was stored near a strong magnetic field for a long time, will that have heavily damaged the tube?

KeithsTV's thread offering this TV contains a photo which suggests to me that it was stored in a garage or some such place. If stored near a device that emits a strong magnetic field, such as a large speaker or whatever, then this could have been the cause of the effect on the screen (as many people put loads of old junk in garages or attics or whatever)

Also, is it normal for microphony to occur on these sets when the speaker is turned up fairly loud? As I've told you, I'm partially deaf so need the speaker turned up to hear it.

EDIT: I have moved the TV so that it is about 90cm away from the nearest speaker. It is sat next to a stack of 4 VCRs, 3 VHS and 1 Beta. Is this far enough?

[HamishBoxer]

Worse possible thing if you get random patches of colour,then you need a degaussing coil to sort it.

David

[AidanLunn]

Originally Posted by HamishBoxer

Worse possible thing if you get random patches of colour,then you need a degaussing coil to sort it.

That's been the general consensus throughout this thread (and even though I seem I'm ignoring everyone, believe me, I'm not).

It has been degaussed twice in the past two weeks by those small rod degaussers, and on both occasions, it still has not gotten rid of the pale red discolouration (and green tint in same areas). KeithsTV backs me up on this, as he has admitted earlier in this thread. The tube is still absolutely fine, as I can faintly see the two thin horizontal lines that are faintly visible on Trinitron tubes. It still produces a constant buzzing in the speaker as well, which is more obvious when plain writing on a black background such as the "do not copy this DVD" warning is shown on it.

I still haven't examined the posistor/degauss circuit as once again it has been a beautiful day and I should not be stuck inside messing with an old TV

The degauss circuit will be examined though, as it's still seemingly dead, and, as another member had a similar problem to me a few years back with one of these sets, further examination of the electrolytics will take place.

Ironically, I'm currently watching One Foot in the Grave on it. Ironic, because this TV must be the TV set equivalent of Victor Meldrew!

[HamishBoxer]

The Degauss coil i use is 12" diameter and think you may need that size.Sorry ,had not read all previous replies.

David

[Sean Williams]

Aidan,

Many members here, with a combined experience level of somewhere near 250 years have told you what you need to do, yet despite all of these comments you still insist on ignoring their advice.

If you cannot move the speakers, the whole concept of sorting out the tube issues is wasted - please heed their advice, this is fast becoming a farce beyond all proportions, and to be honest, is wasting everyone's time.

If you insist on going it alone and doing your own thing, based on your obviously vast experience of colour television repairs please feel free - I wish you luck.

Seeing as the same fix is mentioned several times I will close the thread.