Fixing plasma TV 60 inch .

Discussion in 'Technical Repair' started by Stk.Goose, Aug 13, 2015.

  1. Stk.Goose

    Thread Starter New Member

    Jul 23, 2015
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    i have arrived at a dead point and don't know how to proceed . I am not getting power at all on model Tc-p55gt31 . I found a few post online about blinking light code but this TV doesn't even show blinking light so assuming the standby on the powerboard is out . So far i have checked all capacitors with esr meter and have checked all fuses and diodes . Any help is greatly appreciated .
     
  2. Stk.Goose

    Thread Starter New Member

    Jul 23, 2015
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    This is the TV . Also o volts on all pins tested going out to the main board
     
  3. Gdrumm

    Distinguished Member

    Aug 29, 2008
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    I have a similar situation for which I replaced the Power Board, and still nothing.

    My next step is to strip it down further.

    Original owner said it was working before they moved it across town.

    I will keep an eye on your post, Thanks,
    Gary
     
  4. bwilliams60

    Active Member

    Nov 18, 2012
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    Are you comfortable measuring Ac voltages and DC voltages on the power supply board? If not, then you should pass this on to an experienced television repair personnel. If you are comfortable with it, then have you measured the voltages on the connector that shows 5V, 12V, 24V etc? Do you have anything coming out of any of these terminals?
    Can you take really good pictures of the power supply board both front and back and post them on here and the other forum you are on? I suspect your power supply board is euchered but you probably already know that and that nobody has stock so itvwill have to be repaired at the component level.
    Lastly, is there a part number on the board?
     
    Last edited: Aug 13, 2015
  5. Stk.Goose

    Thread Starter New Member

    Jul 23, 2015
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    howdy bwilliams60. the problem is that none of the connectors are labeled like most tv sets but they all do show 0 volts. i did a few voltages test and i do get the 165 volt across the main filter capacitor but after a few checks i do not see no voltages on any component on the cold side of the board . Only the hot side seems to be running. I am trying to figure out what component actually links the cold side to the hot side on the power board or what the actual process is for it. The part number for the board is noae6kk00005 which i do see on ebay for 50 plus 20 for shipping but I want to learn component level and using it as practice.
     
  6. bwilliams60

    Active Member

    Nov 18, 2012
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    That board doesn't look anything like your board. Not sure how you found that board but make sure before you order one that they are an exact match. Post good pics of your power supply both front and back with no glare and perhaps the forum members can help you at the component level. Otherwise, buy a new board and check voltages on it and then check the same on your old board (for learning purposes).p
     
  7. sheldons

    Active Member

    Oct 26, 2011
    616
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    fault may not be on the power supply panel,its most probably on the ssb panel....unless you have the relevant experience working with these panels you've got no chance....it may be software at fault...if you haven't got Compaire you will not be able to put the set in service mode to check anything...also you may have a faulty z or y sustain board and driver at fault...but without the relevant service manual or a means of putting the set in service mode you've got no chance...these sets are basically throw away items,not like the old analogue crt sets which last some 25-30 years before a failure,are easy to repair down to component level and when fixed go on for a further 25-30 years....you are lucky now to get 3-4 years use before a set fails and is scrapped and you buy another because the repair money wise isn't worth it
     
    Gdrumm likes this.
  8. bwilliams60

    Active Member

    Nov 18, 2012
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    Sorry, I have to disagree. Many of these flatscreen TV's have been repaired very successfully and lived many years afterwards simply by replacing faulty or inferior parts with more superior parts. You do not need fancy software to diagnose component issues although it may be more helpful. Many people fix these at the component level rather than the board level and are quite good at it. You just have to find those people. As for repair money, I just finished fixing a VIZIO 47" TV for under a dollar and about 1.5 hours of labor. Faulty caps are common in TV's and replacing it with a good cap, will restore it back to life. No software involved :)
     
  9. Gdrumm

    Distinguished Member

    Aug 29, 2008
    684
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    I too have repaired a few, which had obvious issues (bad caps mostly), but I've also had my share of those units that just drive you crazy.
    The last one I did cost me about $75.00 (with parts), but as I said earlier, the replacement board didn't fix the problem.

    I broke my own rule "don't spend any serious money to fix it".

    If you have the money to invest in it, do as a previous poster said, and buy a new board, (not a used one, because it may have the same problem as your board), and then if that fixes the problem, start checking components on the old board to see if you can figure out what failed.

    I liked Sheldon's input also, and I think it explains why I'm not batting 1000 with these fixes.
    But hey, it is fun when you can get it to work (for cheap).
     
  10. JUNELER

    Member

    Jul 13, 2015
    31
    5
    PLEASE TRY TO CHECKED THE POWER SUPPLY CIRCUIT.
     
    Stk.Goose likes this.
  11. bwilliams60

    Active Member

    Nov 18, 2012
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    Is there any power coming out of the sub power supply board? Small board to the left?
     
  12. ian field

    Distinguished Member

    Oct 27, 2012
    4,415
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    Its good that you have an ESR meter - but did you check for obvious things like dodgy soldering on the mains in feed. RoHS solder is notorious for failing, sometimes the fracture line in the solder fillet is hard to see - but I'd expect some conspicuous signs of arcing in mains circuits.
     
  13. bwilliams60

    Active Member

    Nov 18, 2012
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    I never thought to ask but do you have any lights at all coming on in this set? Can you see a backlight in a dark room?
     
  14. Stk.Goose

    Thread Starter New Member

    Jul 23, 2015
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    June I am checking the power supply circuit not sure where the problem is .
     
  15. Stk.Goose

    Thread Starter New Member

    Jul 23, 2015
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    No bwilliams no lights at all coming from the set . It is pitched black and not even the stand by light is on .
     
  16. bwilliams60

    Active Member

    Nov 18, 2012
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    Is there anything coming out of the sub power supply. Be very careful-high voltage. Don't do anything if you are unsure of where to test.
     
  17. ian field

    Distinguished Member

    Oct 27, 2012
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    One trick is to power it up for a couple of minutes and then unplug it - check to see if any large electrolytics are holding a charge. If not; the mains may not even be reaching the rectifier.

    Care is still needed, apart from the fact some electrolytics can hold a dangerous charge - poking test prods among the semiconductors can accidently switch one on. In SMPSU circuits, there can be enough charge in a reservoir capacitor to saturate an inductor core - this usually destroys the component that switched the current.
     
  18. Stk.Goose

    Thread Starter New Member

    Jul 23, 2015
    23
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    the filter cap and other caps do seem to hold charge.
     
  19. ian field

    Distinguished Member

    Oct 27, 2012
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    After the rectifier, you should find the PFC front end, all I've seen so far were basically a flyback boost converter - on a 230V TV the reservoir cap that follows the PFC would be rated 450V rather than 385 or 400V.

    The reservoir usually feeds a half bridge SMPSU, the transformer that drives, will have multiple secondaries. Usually there's an over current shutdown, so a shorted secondary rectifier can stop the show - or it may be simpler to try unplugging the power leads to other boards and see if one of those is loading it down. But some sets will detect a missing board and go into fail-safe mode!
     
  20. sheldons

    Active Member

    Oct 26, 2011
    616
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    The use of Phillips Compaire makes it much easier as if you have a set with no display for whatever reason you can still check settings in service mode and if necessary via Compaire you can update the main boards software which will then give you a working set...if its a software problem. ....myself I can and have repaired the ssb panels with the help of the relevant service manual, but you do need to know a few tricks when working with this type of multi layer plated thro pcbs. ..and it isnt just me but other engineers I work with hate most makes of lcd and plasma sets due to the fact they are built to a price, are unreliable and depending on the fault the price of a replacement pcb if available is ridiculous. ...which means that the customer scraps the set and buys new!!...especially invertor tx's....at the moment on another site I use there is a big rant going on regarding spares availability and prices and reliability. ...a standard now obsolete crt tv runs for 25 -30 years then packs up, is easily repaired to component level, and will go on for another 25-30 years. .....not so with lcd or plasma. ....
     
    Last edited: Aug 25, 2015
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