# Making a repair on my computer monitor



## cathead (Jun 1, 2020)

I'm using a RCA L32WD12 flat screen television for a computer monitor.  Over time, the screen became unstable
and it got to the point that it was barely usable any more.  The switching mode power supply was failing due to
a bad electrolytic capacitor.  I used an ESR tester to locate the problem and found that one of the electrolytic
capacitors was low on capacitance and had a high ESR as well.  An Ungar soldering iron was chosen to remove
the defective part as I was able to heat both solder pads with the tip.  After replacing the part and reassembling the
case, It fired up and has been working gleefully for about a half hour now with no sign of instability. 



	

		
			
		

		
	
    It would have been nice to have one of those solder sucker devices but I used some solder wick instead to open the holes on
the circuit board after removing the old capacitor.   My old vacuum solder sucking device failed to hold together so maybe it
is time to invest in a new one.  Repairs like this can be made with rudimentary tools but it becomes more difficult.

The monitor has been working perfectly for well over a half hour so I feel like I have achieved satori since most of these
flat screen units with the SMPS power supply end up as electronic waste which is what it was when I got it three years ago.


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## 7milesup (Jun 1, 2020)

That is awesome.  I too like to "save" something that may end up in the trash.


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## Winegrower (Jun 1, 2020)

Anybody who can use solder wick on a PCB successfully has my respect.


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## pdentrem (Jun 1, 2020)

Good going! I see a burn area by the word Hot! Something was hot!
Pierre


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## RJSakowski (Jun 1, 2020)

I've used solder wick for more than forty years.  I find that it doesn't work too well with the plated through holes which are common to most of the current p.c. boards.  The wicking of the hole action is fighting the solder wick and gravity isn't helping the situation.  

I have a stainless steel probe which has a long taper and comes to a point that I use to open the plated through holes.  I insert the probe while the solder is molten and it leaves a clear passage for the new component lead.  The stubborn cases, flipping the board and inserting the probe prevents solder from refilling the hole.  Solder wick can then be used to clean up the back side of the board.


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## SLK001 (Jun 1, 2020)

If you find a TV along side the road, most likely it has a failed SMPS (99% failed caps).  The other common failure mode is someone threw something at the screen and cracked it.

I use solder wick and a spring loaded solder sucker to remove the solder.  If the solder is Pb-FREE (most are), I add regular tin-lead solder in order to bring the melting point down enough so that the heat doesn't damage the board itself.  It also facilitates the solder removal and wicks much easier.


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## markba633csi (Jun 1, 2020)

I use all three, depending.  Desolder machine, wick, blue plunger, and sometimes just whack the board after heating the pad
-M
Those new cheap LCR testers from China are great! Just got one too


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