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Toshiba Projection TV Help.

Discussion in 'Electronic Repair' started by PiNhEaD, Sep 9, 2003.

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  1. PiNhEaD

    PiNhEaD Guest

    I have a Toshiba model TP5580A projection TV that was given to me by a
    friend. This is a older unit manufactured in 1992. I was told the picture
    was blurry so I cleaned the lenses and the mirror before plugging it in and
    the picture is nice and bright and crisp believe it or not. But when I turn
    it on there is a horizontal line in the center of the TV. It looks like the
    picture is getting sucked into the line. After it warms up for about 5
    minutes the line moves upward about 12 inches above center and becomes very
    faint. At this point nothing is being sucked into it anymore and it is just
    a couple of small faint lines. You can only see the lines when the TV has a
    light picture on it. Anyway most people don't even see the lines at this
    point but it is driving me crazy. I have never worked on a projection TV
    before but I do repair arcade monitors on a regular basis. Based on my
    experience with arcade monitors I would think the problem lies with the
    horizontal output transistor either starting to go bad or a cold solder
    joint. But I do not have any schematics or service manual to work from.
    Unlike an arcade monitor which has one circuit board this has several pcb's
    as well as 3 crt's. Can anyone point me in the right direction or better
    yet tell me where I can obtain a service manual and schematics, preferably
    in adobe acrobat format. I have been searching google for the last 2 days
    in my free time looking for anything related to this issue and found
    nothing. I did see many posts about fluid leaking out onto the boards
    causing a variety of problems but nothing like this.


    Thanks, in advance

    Pat
     
  2. David

    David Guest

    If the service manual is still available, you need to buy it from any
    Toshiba authorized parts dealer. Toshiba has a pretty strict policy of only
    selling service information to servicers for what they call legal liability
    issues.

    As to your problem, you need to look for high ESR capacitors in the vertical
    deflection circuit and power supplies. If you are not sure how to do this,
    you are probably better off having the unit repaired by an experienced
    technician. Most repairs if the set is mostly working and you can take it
    in on a set like this come in well under $250 total.

    David
     
  3. heypat1

    heypat1 Guest

    Well there is no way im taking it in for repair, what fun would that be.
    If I were that lazy I would just go buy a new one money is not the
    issue. I am more than capable of testing and replacing capacitors, every
    monitor I rebuild gets a complete cap kit. Since I know the problem
    dissipates when the set is warm I will start tonight with a can of
    freeze spray to try and isolate the component. I still want to get my
    hands on a service manual, I can find the bad component and replace it
    if I poke around enough but lets face it life is much easier with a
    manual and a set of schematics. Sure would be nice to check my voltages
    and make sure they are O.K.

    As always any help is appreciated. Still looking for a service manual.

    Thanks,

    Pat
     
  4. john

    john Guest

    You dont need a service manual to ESR caps ...

    kip

    --
     
  5. David

    David Guest

    You should have no problem identifying the vertical output circuit as it
    likely will be an IC or a couple of transistors on heatsink nearly directly
    connected to one side of the deflection yokes.

    Then there is the jungle ic which does most of the signal processing and
    sync processing, 64 pin or so ic.

    Toshiba may still have been labeling the boards in 92 with the general
    locations of the circuits.

    The service manual will be a tough one to find. In 92 Toshiba had
    relatively few authorized servicer which would have had the manual. Since
    then many independent servicers have simply gone out of business. You might
    get lucky and find a local servicer that is willing to sell you the old copy
    (if they have one) as odds are very low they will ever see that model again
    due to the extreme old age.

    David
     
  6. PiNhEaD

    PiNhEaD Guest

    Very little time to look at it tonight, had to work late and open house
    (meet the teachers) at my sons school. I did have about 45 minutes when I
    got home from work earlier. I followed the wires back from the yoke to the
    board knowing this would get me in the general area then I looked for the
    transistor on the heat sink and started spraying components one at a time
    with the freeze spray. Knowing the problem went away when the set heated up
    I let it warm up first until the problem was almost gone. Then when I hit
    cap # 332 and 315 with the freeze spray the problem comes back right away
    and 10 x worse. Just to confirm I heated it back up with my heat gun and the
    problem went right away. These 2 caps are right next to each other and it
    was hard to spray one cap with the freeze spray and not the other, same goes
    for the heat gun. I do not have a esr meter so this was a quick way for me
    to find the bad component while the board was still in the TV. I pulled the
    board and wrote down the capacitor values so I can pick them up tomorrow.
    Figures I have hundreds of caps around that I use all the time on arcade
    monitors but I did not have a 160V 220 mf anywhere. I hope to have time
    tomorrow to pull my out my scope and function generator so I can check the
    esr on the rest of the caps. Only makes sense to check all of them and
    replace any bad ones while the board is out.


    It would still be nice to run across a service manual. There is so much more
    to these then arcade monitors I wanted to get the service manual so I could
    take a good look at the circuits and any material related to the lenses and
    the fluid in the lenses etc. Always looking to learn more

    Thanks for the help and I will keep you posted.

    Pat
     
  7. PiNhEaD

    PiNhEaD Guest

    Replaced the 2 caps I hit with the freeze spray and found 2 more that needed
    to be replaced. Fired it up and it works great, picture is even better then
    before. It has been running for about 3 hours now with no issues.

    Thanks for the help

    Pat
     
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