Re: Sony tv color reversal

From: Art (plotsligt_at_comcast.net)
Date: 03/27/05 

Date: Sun, 27 Mar 2005 07:43:36 -0500

Very common with Sony and Panasonic sets. Also a common problem:
intermittant fuse failure due to the current being initially used by the dgs
circuitry. Seen a lot of Thomson and Panasonic sets with this senerio.
"Donald Gudehus" <gudehus@gmail.com> wrote in message
news:1111888235.595543.3190@o13g2000cwo.googlegroups.com...
> Thanks for the great information! From a Google search I found the
> information in this thread I needed to repair my Sony KV-20TS30 TV
> which suddenly developed color gradients in an oval pattern. My
> problem was just as described here: the THP601 thermistor (black
> 1/2x5/8 inch component next to where the degaussing coil plugs into the
> main circuit board) had no solder left on the center pin. I could also
> wiggle the lead. Turning the set upside down and applying solder got
> the set working again.
>
> Terry wrote:
>> Sony tv color reversal: SUCCESS!!!!
>> This MADE my week! I'm a hero in the extended family! Wednesday
>> night I finally brought home my soldering equipment (not too much
> call
>> for soldering DB25s in these days of the 100MBit office anyway!),
>> pulled the back cover, turned the whole set upside down and confirmed
>> all the hints from you guys:
>> The degauss wires were indeed covered with black tape. The circuit
>> traces went from those wires directly to one of the black boxes which
>> did indeed have 3 pins (I had to shine my bright light *through* the
>> circuit board to see this clearly - might be a good hint for
> beginners
>> in the future)...and LowAndBehold, one of the pins was NOT SOLDERED
>> ANYMORE (guess how excited I was) It was not burned looking in the
>> least, just no longer soldered and in fact I could gently wiggle it
>> and feel that it was not solidly connected. I then KNEW you were
>> right.
>>
>> I fired up my iron, used the hot iron itself to clean up the pin and
>> hole and gave it a nice quick small flow of fresh solder. I kept
>> wanting this to be more difficult... but I just closed the tv back
> up,
>> plugged it in, turned it on and there to the shocked amazement of my
>> family was a PERFECT COLOR PICTURE! Total Cost: a few good
>> descriptions to this group and a speck of solder. You guys are
> Great!
>> I'm going to re-visit the crippled stereo equip in my lower room now!
>>
>> Final Hindsight data: The component was marked "THP601" on the
>> circuit board (I decided this must mean "Positive" acting
> "THermistor"
>> or "Posister" as Sam mentioned and an electronics friend said meant
>> just the opposite direction for the voltage or the temperature.)
>>
>> Terry
>

Relevant Pages

  • Re: Cordless, cool touch soldering tool
    ... There's a small circuit board in there. ... Follow the wires. ... The device has no electronics in it The batteries are just connected to ... Solder doesn't stick to the tip so there's no issue with the solder ...
    (comp.robotics.misc)
  • Re: cold solder joint
    ... in service a circuit may short out. ... It was clear that the solder was very light on that lead. ... >If I don't use my car for a day or so the radio will not work no red ... >I took the CD player into the house until it was up to room temperature took ...
    (sci.electronics.repair)
  • Re: Wristwatch battery.
    ... Yes, especially the solder job. ... actually if you have a look at the circuit board, all the components are hand soldered on, you could buy new crystals and trimmers for these years ago, Omega normally do an exchange on circuits, the old circuit was returned to the factory to be refurbished. ... I have a circuit on order for another omega, cost to me is AUS$120 or so, just to give you an idea of the cost. ... normally I don't like 'rodding' the movement, in most cases there is a silver oxide battery that is either the same size or very close to the old mercury one, but a 388 has no equivalent, and the 10month run time was really annoying the old guy, so I did the mod, at least now the new battery is similar to the capacity of the old mercury battery. ...
    (alt.horology)
  • Re: Understanding circuits
    ... because it helps me understand how various pieces of a circuit are used ... I recently purchased a hit from Ramsey Electronics. ... how a capacitor and a resistor can be used to form a timing circuit - ... thinking about just breadboarding everything before I actually solder ...
    (sci.electronics.basics)
  • Re: Help...Sony KV32S20 wont turn on
    ... Be aware Sony is known to have bad solder... ... Ask a second repairman to see if he tell you that these circuit are gone... ...
    (sci.electronics.repair)