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From: behindontaxes on 26 Jan 2010 00:51
I have a non-working Maxent MX26X3 LCD TV/monitor. Immediately upon
powerup, it will generate anomalous vertical multi-colored lines
throughout the entire screen with a blue background.

I've read about two known solutions, and I think both are related to
one root cause. On FixYa, people have reported favorably changing
the behavior of the TV by twisting a green heatsink that sits on top
of a 208-pin QFP. That QFP is made by Trident, so I suspect it
handles the video. One person used heat to reflow the pins.

There's a thread on badcaps.net featuring the MX-26x3 TV but nobody
has posted successful repair by replacing the capacitors.

I'd like to try something similar to reflowing the pins. While I
have access to a heat gun, I can't accurately gauge temperature. I
also don't have a temperature marker. I think I would ruin the work
with thermal shock from cooling down.

I was considering adding more solder to all 208-pins by flooding the
pins with solder and using solder braid to remove excess solder and
bridges, etc.

I'd love to get your thoughts on how to go forward with trying to
repair this TV.

Thanks for reading.
From: Sansui Samari on 27 Jan 2010 03:34
On Jan 25, 9:51 pm, "behindonta...(a)xemaps.com"
<behindonta...(a)xemaps.com> wrote:
> I have a non-working Maxent MX26X3 LCD TV/monitor.   Immediately upon
> powerup, it will generate anomalous vertical multi-colored lines
> throughout the entire screen with a blue background.
>
> I've read about two known solutions, and I think both are related to
> one root cause.   On FixYa, people have reported favorably changing
> the behavior of the TV by twisting a green heatsink that sits on top
> of a 208-pin QFP.    That QFP is made by Trident, so I suspect it
> handles the video.   One person used heat to reflow the pins.
>
> There's a thread on badcaps.net featuring the MX-26x3 TV but nobody
> has posted successful repair by replacing the capacitors.
>
> I'd like to try something similar to reflowing the pins.   While I
> have access to a heat gun, I can't accurately gauge temperature.   I
> also don't have a temperature marker.   I think I would ruin the work
> with thermal shock from cooling down.
>
> I was considering adding more solder to all 208-pins by flooding the
> pins with solder and using solder braid to remove excess solder and
> bridges, etc.
>
> I'd love to get your thoughts on how to go forward with trying to
> repair this TV.
>
> Thanks for reading.

We used to solder fine smt parts like this sometimes by hand at the
board shop I worked at years ago. One method was what they called
"drag soldering", not to be confused with an actual drag soldering
machine. We would use a fine soldering iron, and rosin core solder.
As long as you are fast enough, and have enough flux present you can
work from one end of the chip to the other, and just add solder to
keep a small ball following the tip. This takes a lot of practice to
master. Being that you only have one chip I wouldn't recommend trying
it. The other way was to use a magnifying glass and a fine tip, with
rosin core solder and tack each leg down. You only need a very tiny
amount of solder. Mostly you just need the flux from the solder to
get the old solder to wet. Try not to let the solder creep up the
legs, it can be bad for the component.
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