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Toshiba 42WT29B Red Flicker

Discussion in 'Televisions' started by jamesgrahamuk, Oct 19, 2004.

  1. jamesgrahamuk

    jamesgrahamuk
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    I wonder if anyone can help me?

    I have a Toshiba 42WT29B Rear Projection TV which has performed perfectly well for the past two years. However, I have recently noticed a faint red flickering which is more noticeable on red coloured or very dark areas of the picture. This effect seems to manifest at random intervals for between five minutes to over an hour and at any time - sometimes at power-on, sometimes after a couple of hours of usage and sometimes not at all.

    More recently, this has become more severe either manifesting as a faint, but steady (not flickering) red cast which effects the entire picture for long periods of time or on one occassion as quite violent red/green flickering.

    I notice that when I turn the TV off during this activity I get a red burst or discharge across the screen. (A bit like your Nan's old CRT used to do!) Unfortunately, switching off the TV, letting it settle and then turning it back on does not necessarily cure the problem.

    It's a shame really, as 90% of the time the TV performs perfectly well. Does anybody have any ideas - is this worth getting repaired? And, if so,what should an engineer be looking for? I am assuming there is a problem with the red gun - has anybody else experienced anything similair with Tosh RPTV's?

    Thanks in advance...
     
  2. weyland-yutani

    weyland-yutani
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    i would instantly say, yes, of course it's worth getting repaired. to replace the unit would still cost over £1000, so get a tosh engineer out and get a quote. if it's been a good tv till now there's no point giving up on it. unless of course you enjoy the nightmare of buying a new tv? :nono: ;)
     
  3. jamesgrahamuk

    jamesgrahamuk
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    Well, (and this is the sad part) I have just ordered a projector and had also agreed a sale of the television which was going to pay for the projector screen.

    Now, in this condition, there is no way I can sell the TV in good conscience - leaving me with a projector and no screen and a broken TV...

    Boo-hoo...

    :(
     
  4. Laurel&Hardy

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    The effect you describe is known as afterglow or stray emission. It's caused by particles on or near the electron gun conducting anode voltage at random intervals, which makes the picture unstable when you view it, and causes the glow that you see after switch off because it's conducting the residual anode voltage in the CRT. It's possibly been blown there by an static reaction within the CRT, or it just may have fallen into the electron gun assembly. All CRT's have a certain level of particles in them, it's just in most cases they usually get vaporised or get attached to areas that don't affect picture performance. Sadly you've been unlucky and it means that the CRT has to be replaced :(

    Get the Tosh engineer out, see if you can get a good deal.
     
  5. jamesgrahamuk

    jamesgrahamuk
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    Laurel&Hardy,

    Thanks for your reply, that's exactly the kind of information I was looking for. Any ideas what a replacement CRT would cost?
     
  6. jamesvtidohc

    jamesvtidohc
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    im guessing to replace the crt including labour and tax would be about 500 quid? just a guess though, and the reason for that guess is because ive read somewhere that to replace the crt, is as much as replacing the whole unit. its could be more, it could be less but thats my guess.
     
  7. runningback

    runningback
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    I would think round about £300 for one colour tube. The problem with CRT RPTV's is though that you will very likely end up with a colour imbalance due to the replacement tube being so much newer than the other two.
    If you have to change them all three it would amount to the cost of a complete TV.
     
  8. Laurel&Hardy

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    Unsure of cost, I think £300 would be excessive but nothing would surprise me these days. It really depends on the cost of the tube - I'd guess at around £100 but that really is a guess. Remember these are only 16cm CRT's of a single colour and single gun with no shadow mask, degaussing, ect, so nothing like as complex as even a small 14" colour CRT. The extra cost will be the housing the CRT sits in, all the sealing rings and the coolant it's filled with. I'd be very surprised if you don't get the whole assembly when the replacement part is fitted because the housing has to be watertight and pre-filled to a set volume.

    A rough plan of the job would be:

    1. Replace tube (obviously!)
    2. Reset the screen voltage and focus
    3. TV left on heat run for at least 30 minutes
    4. Fine tune screen voltage and electrical/mechanical focus
    5. Re-align the red convergence to the green - green is the reference grid
    6. White balance
    7. Final check that everything is ok
    8. Hand the set back to customer.

    A good technician should be able to do this in about 2 hours at the customer's home if he knows what he's doing, has a white balance meter and a good pattern generator with highlight/lowlight adjustment as part of the kit. I'd be surprised if they asked you to bring the set in considering how big it is and the risk of damage by moving it to a repair centre. If you assume £100 for the tube then job done for £200 perhaps? Again, just a guess.

    The issue of how much life is in the other two tubes really depends on how hard they have been driven, so if you can get these assessed assuming the engineer can do that. Really all you're interested in is that the phosphor on them has burnt consistently and if they have then that's ok. Additionally, if you have used the TV sensibly (for example not using reset 1!) and had the contrast around 50 or so then I'd say that they probably still have a good few years in them.

    Hope this is useful.
     
  9. jamesvtidohc

    jamesvtidohc
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    While the LG RE-44SZ20RD was attractively priced initially - too my cost have discovered that the lamp has only a limited life span and costs £450.00 to repair/replace.

    quote from: http://www.reviewcentre.com/review132866.html

    although is this a LG model, it also is a crt projector like yours, so i guess this is how much it would cost to replace the lamp.
     
  10. runningback

    runningback
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    The LG is a DLP projection TV. They have one lamp, that can be replaced when it blows.

    The Toshiba is a CRT rear projection TV who has no lamps at all, instead it has three CRT tubes, one for every primary clour red, green and blue.
     
  11. jamesvtidohc

    jamesvtidohc
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    ahhhhhhhhhhhhhhhhhhhhhhhhhhhhh DUHHHH ME, MY BAD!
     
  12. Laurel&Hardy

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    Yep, THE big drawback of DLP's. I love how that's a 'user replaceable' part at the princely sum of £450!
     
  13. runningback

    runningback
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    yes it is a drawback, but the manufacturers are getting better at handling the DLP tec, Optoma now quotes 10000 hrs for their lamp and the replacement is around £250.
    One of these DLP's is definitely going to rplace my CRT RPTV in a couple of years or so.

    jamesgraham sorry for getting off topic, hope you get your Toshiba sorted at a reasonable price.
     
  14. SMX-

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    Well another :devil: Tosh, 42WT29B "Problem!"

    Listen Bud! You’re really up against it with this TV, in fact most TV’s engineers on the Wirral/Cheshire or even Merseyside!
    ( Will not touch a "Rear Projection TV" ) :lease: No, No...No No!

    Oh-Yes :devil: "Toshiba" will recommend 1 or 2 if your lucky, I mean really lucky. But this is, were the problems and your expense, start to you through the roof "Toshiba Approved Repair Centre" :laugh: ha-ha.

    For starters, they will not do that type of repair in your home, unlike some people on this post think they will or should :nono: They will come out to you & pick the TV up, and then take it back to the repair shop. But before they will do that "You'll need to pay them £50 to pick it up + £50 pound to look at it. And that’s with "No Guaranty" it can be fixed :eek: Yep that "Toshiba Approved Repair Centre" for you!!! Oh-yes If it can be fixed the £50 comes of the bill :rotfl: Oh really!

    I’ve said it before & I will say it again "Before you invest in new "Technology" make you can get it repaired after the warranty runs out!!! ;) Specially rear projection & plasma TV’s.

    It's highly likely that you will be looking a bill of at leased £360 / £380 + vat for replacing those small CRT heater tubes.



    SMX-
     
  15. Laurel&Hardy

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    Notice the words in my post 'if they know what they are doing'. I'll rest my case.
     
  16. johno199

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    hi just seeing if you got your tv sorted as i need a new screen as mine is broken if you have could you give me a price please

    thanx steve
     

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