Sony KV1800UB C.R.T. Spots

[chroma04]

Hi,

Firstly, I believe this issue has been mentioned on this forum before, so mods please accept my apologies if this is the case. I have a question concerning my Sony KV1800UB television set.

Basically, over the last year or so, the set has developed 'spots' in the corners and top edge of the C.R.T. This is a physical issue rather than electronic, as the spots/marks are present with the power off. I seem to recall that I have read about this issue before (perhaps on this forum) that the C.R.T. has a glass frontage that is bonded to the actual C.R.T. so could the issue be due to the adhesive failing at these points?

I should perhaps mention that this issue seems to have occurred during a recent house move, where the set was in storage for a couple of days, so could this be the root cause of the issue, due to changes in temperature/humidity, for example?

The set is now installed in a warm room and doesn't appear to be getting any worse, however I'm just curious to hear of any forum members' thoughts. Also, are the 'spots' likely to spread over the whole area of the C.R.T. face, in time?

Thank-you in advance,

Adrian.

[Paul_RK]

My KV1800UB has quite a nasty case of these too. I think moisture must have been responsible, I noticed the spotting after it had spent some years on the floor in an unheated and somewhat damp front room. That was in our former house, which we left five years ago: it's now in an unheated bedroom, but with no particular damp problem and dehumidifiers at work in winter, and I don't think the spots are spreading.

Paul

[jhalphen]

Hi to all,
Hi Chroma04,

See a photo i gleaned from a forum (maybe here), also a Sony 19" Trinitron.
Much worse case than yours.

It is indeed dampness/mould ingress between the plastic laminated annti-implosion protection and the actual CRT glass faceplate.

No solution was offered other than dissolving the glue (which type?) to separate both.

In the USA this is a well-known problem with 1960s round colour CRT, and it's called "cataract".
Numerous YouTube videos on the topic.

Their solutions, depending on CRT maker & glue type :
- hot air gun (danger!) + steel wire pulled across for separation.
- soaking CRT in water for days, then picking with a wooden dowel.

In both cases, it's messy, requires patience and suggested as an outdoor job.
...and you have to entirely remove the CRT from the receiver.

Sorry! for no quick & easy fix.

Best Regards
jhalphen
Paris/France

[simpsons]

Jerome is spot on. No pun intended!!

I had the same problem, and removing the gel using a flexible bade was quite difficult.

Another idea is to inject butylacetate into the gel which will dissolve the gel slowly, adding additional injections as required.

Chris

[chroma04]

Thank-you to everybody for the replies.

The issue does appear to be as I suspected, possibly instigated due to the move and subsequent storage.

Paul, it is encouraging to hear that the issue does not appear to be worsening with your set. I'm hopeful that, given its current location, mine will not progress.

As has been suggested, the remedy of removing the laminated anti-implosion protection (by whatever means) sounds like a big job and would in any case be well beyond my abilities. As such, I think the set is best left alone. At least I now know what the issue is!

Best Regards,

Adrian.

[toshiba tony]

What an interesting problem, I spent a lot of years at Sony but never saw this problem. I have dementia now but even the 1810's didn't scare me. So what happens to the tubes on these? We used to get low emission and I seem to remember they were low focus potential sets but this is a new one on me.

[greg_simons]

Originally Posted by toshiba tony

What an interesting problem, I spent a lot of years at Sony but never saw this problem. I have dementia now but even the 1810's didn't scare me. So what happens to the tubes on these? We used to get low emission and I seem to remember they were low focus potential sets but this is a new one on me.

New one on me too, it's possible age is causing problems with their construction that the original designers had pushed to a point waaay beyond their expected service life, or adverse storage conditions may be to blame, did many many back in the day, only low emission and the extreme cost of a replacement crt made them ber.

[simpsons]

It is down to the chemical formulation and an issue with computer monitors but when recognised as a problem, the formula was changed.

My KV2000 has started to show signs of a cataract with yellowing around the edges. I've also had the black spot issue with an KV1800 now kept for parts whilst the good'n is kept in a low humidity environment. The CRT in this one is too good to muck about.

Chris

[Mr Hoover]

I have a 1330UB with spots at the
top right of the screen. It was like that when
I was given it in the late 1990's and has
not got worse since.It could well
have been stored in damp conditions
as had not been used for a while when
it came into my hands.

[Welsh Anorak]

I had a KV1800 with the inevitable poor tube so it was stored in a shed. A year later and, yes, the same had happened around the edges.
I did offer it around, but as there was undertandably no interest it was disposed of.

[chroma04]

I'm very interested to hear these comments from other forum members.

My particular set is one which I had been keen to acquire once again, due to having owned one as a teenager in the early 1990's. I suppose they were considered to be an old set even back then!

Adrian.