The next common failuer [food for thought]

[alexanna]

I am going to make a prediction, have seen some evidence that we will see this more of this.
I think it's time for people to get comfortable going into the LCD panels and at the minimum repairing poor soldering on the CCFLs.The good thing is testing will be straight forward and easy.
Granted replacing bulging capacitors is easier, but repairing a poor connection on a CCFl if that is indeed the problem is going to be easier than dealing with the protection circuitry of the inverter. It's next to impossible to find a schematic, and what are we going to if the manufacture starts using more of what I think it's been called “in house numbers” on their ICs?
It gets very pricy replacing CCFLs,But in my opinion There is nothing wrong in using a good used CCFl from another monitor that for one reason or another we have decided not to repair.
Something's I have noticed with wiring on CCFLs are:
What we call 2 sec to black, this time period could go up to 5 minutes or more.
Flickering of the LCD panel particularly when everything is good and warm.
And in severe cases sizzling coming from inside the panel or the inverter coil

[sam_sam_sam]

Re: The next common failuer [food for thought]

I would second this idea

[PlainBill]

Re: The next common failuer [food for thought]

The economics has shifted to the point that purchasing a set of new CCFLs to repair a 19" monitor is uneconomical. With 20" wide screen monitors selling for under $100, even replacing caps is barely worth it. Still, on the larger size monitors it's worth it.

There are two problems with going into the LCD panel. It requires significantly better mechanical skills, and cleanliness is very important. I've got one in front of me right now that I didn't do very well on.

PlainBill

[Rtech]

Re: The next common failuer [food for thought]

I have found over many months that the fault associated with CCFLs,is more likely to be a wiring fault as opposed to a lamp fault itself.The wiring fault always seems to be on the return wire end of the lamp,and is usually a burnt out wire or bad joint.I considered either bad soldering in manufacturing,poor quality solder, or poor quality return wire,and dismissed a burn out due to excess current as the CCFL current is usually no more than 8-10 ma dependant on lamp length.On a number of lamps,where the return wire is burnt out I have recently replaced both return wires with 30AWG Kynar wire,3Amp current rating, heat reisistant in excess of 105degrees,and very easy to work with as this was mainly used in wirewrap applications,and therefore it is easy to put a number of turns on the lamp contact,making a very good mechanical joint,and then solder as normal.A lot of 'soak' testing outside a screen seemed to be fine,so the next test would then be to run them in situ in a Monitor,and see what happens.My son has been running one for a number of months with no problem,as has my daughter,so I have decided to continue using this system.

[retiredcaps]

Re: The next common failuer [food for thought]

I think it's time for people to get comfortable going into the LCD panels and at the minimum repairing poor soldering on the CCFLs.The good thing is testing will be straight forward and easy.

Of course, I get a nice Acer 19 inch 2008 circa wide screen monitor that according to the previous owner won't stay powered on. I was hoping for bad caps and an easy fix.

However, I could hear arcing and feel the top corner of the monitor get warm. Finally, I decided it is time and take one of these lcd things completely apart since this monitor was made in 2008. Sure enough, I can see the burnt crispy return wiring. Sigh.

The bulbs are good (no signs of damage). Now to figure out how to do this without wrecking anything.

Time to look at the ccflwarehouse and ccfldirect tutorials in greater detail.