Two Acer AL2223W_TD with bad inverter xformers

[budm]

Same model, same problem, same bad transformer.

[Jasgriff]

Re: Two Acer AL2223W_TD with bad inverter xformers

How is that last picture lighting up the CCFL's? it looks like there isn't one on the board?

Poor how it seems that these transformers are made so bad. Looks like a nice monitor otherwise. Is this a recent monitor you have had to fix or is it from your archive?

[budm]

Re: Two Acer AL2223W_TD with bad inverter xformers

The last picture, all 4 lamps are lit after I installed another transformer from the boards I saved from broken screens (I have boxes full of boards that I saved them for repair). I fixed one over a year ago, then yesterday we received two from the same company that brought them in for recycle.
The funny thing is that they all have the same failed winding on the transformer. So I am sure there are lot of this monitors with the same bad transformers.
At least the school will now have two 22" monitors to use.

[Jasgriff]

Re: Two Acer AL2223W_TD with bad inverter xformers

Yeah did you see my thread on the X22W I have 8 of them. 5 of those have the same transformer fault on the same winding too!

[b700029]

Re: Two Acer AL2223W_TD with bad inverter xformers

i have a problem where the monitor turns on for one second then shuts off, people point to the transformer, so i took it out and tested it, it has 1.010k and about 980ohm on outside and .3ohm on the insides, so pretty close to the original spec, any thoughts on the readings or what else could cause this?

[budm]

Re: Two Acer AL2223W_TD with bad inverter xformers

b700029, you may have bad CCFL. I use test lamp to veify the function of the inverter board if the voltages and caps are OK.

[selldoor]

Re: Two Acer AL2223W_TD with bad inverter xformers

The resistances are just about on the 3% difference if you couple that with worn bulbs it could be enough to trigger the protection circuit. Did you try swapping leads - top bulbs for the bottom ones check the wiring to the ccfls and the sockets - anything that might affect the resistance.

[budm]

Re: Two Acer AL2223W_TD with bad inverter xformers

You should also check the ballast caps (small caps by the lamp connectors) for value and leakage resistance.

[b700029]

Re: Two Acer AL2223W_TD with bad inverter xformers

i decided to play with it some more, i opened up the lcd screen part, because it thought there are come solder CCFL connections to check there, well.... there aren't, and i got the screen all dirty and in the process of cleaning it i messed it up even more, ooops, another one bites the dust