(again) AL2216W - 15s to black

[hitz]

Hey guys!

As it seems, my Acer AL2216W is getting old. I thought my last thread was longer ago than it acutally is. But I dont want to replace the monitor without even trying to repair, because I bought it 7 years ago with my first ever earned wage. So I hope you can help me bringing it back to life for the third time

Here is the problem: After turning it on it starts as usual (acer logo, light off+on, showing desktop). Then it takes nearly 15 seconds till the backlight turns off (LCD still shows the correct desktop and actions, so no problem there, checked with a flashlight).
I've read the instructions for the "2 seconds to black" problem, but I hope you can give me any advices to shorten the trouble shooting. Due to the longer timespan until lights shut down, there might be some failures listed that dont fit to my actual problem.
I currently have no camera to take pictures of the circuit boards, so please see the ones in my old thread. Tomorrow I'll have a camera to take new pictures.

[Lumberjack777]

Re: (again) AL2216W - 15s to black

Hi. Excellent job of explaining the symptoms. Sounds like a lamp/inverter problem. I'm guessing that you have a ccfl that is starting to go. After it warms up a little the feedback circuit detects some sort of fault and shuts off the lights. You need to find an extra ccfl and test them like Retiredcaps explains in his 2 second to black guide.

See if you can't find a monitor/TV recycle center in your area and buy one (or two) ccfl's from them.

If it does turn out to be a ccfl, and you don't want to rip it all apart (or order and pay for an exact size ccfl); you can use my trick of plugging in the good ccfl and then duct taping it to the lcd panel and running off 3 lights.

[hitz]

Re: (again) AL2216W - 15s to black

Thank you for your reply, Lumberjack. The only CCFLs I own, are two blue ones with a length of 10cm each (like those). Both are connected to the same inverter. Unfortunately they have different connectors than the CCFLs in the display. So I hope someone can tell me if the test would work with those CCFLs, so I can start and solder to make them connectable.

Attached you'll find the new pictures of the circuit boards, with a detailed view on the inverter/CCFL section. Please excuse my bad soldering job on the regulator

[budm]

Re: (again) AL2216W - 15s to black

Do you have some old cfl?
https://www.badcaps.net/forum/showth...er+testing+cfl
BTW, I will assumed that you have closely inspected the solder joints on the board.

[hitz]

Re: (again) AL2216W - 15s to black

I just tried the other way round. I used my inverter to check the display's CCFLs. That made me realize that the CCFL connected to the top connector (top left corner as seen from front) seems to be broken. Trying to let the display run with only three CCFLs connected brings the monitor into standby mode before the acer logo shows up.

@budm: What solders you mean? I didn't recognize a faulty solder when visual testing, but didnt measure all of them. I only tested the power line for the MOSFETs next to the transformers, because I recognized the voltage dropping when the monitor turned black. So I followed the circuit line, but without further findings.

[budm]

Re: (again) AL2216W - 15s to black

I mean inspect the solder joints for any cracks or cold joints on the board.

[Lumberjack777]

Re: (again) AL2216W - 15s to black

I just tried the other way round. I used my inverter to check the display's CCFLs. That made me realize that the CCFL connected to the top connector (top left corner as seen from front) seems to be broken. Trying to let the display run with only three CCFLs connected brings the monitor into standby mode before the acer logo shows up.

Ok, so it was a ccfl afterall. I wasn't saying to just plug in 3 lamps. (That will not work). But to purchase one from a place that recycles old monitors. You'd want a good ccfl about the same size or smaller, with the same type of connector. Then you plug it into the inverter INSTEAD of the bad lamp. Now you have 4 ccfl's plugged in. (3 inside, and 1 outside the panel) Then you take that lamp that is outside, and duct tape it to the lcd panel. That way you don't have to tear everything apart, and measure, order, desolder/solder, and pay for a new ccfl. In my experience there is no noticable difference in the display using 3 lamps to light it. Just a suggestion to same you time, effort, and money. On an old monitor. But still bring it back to life

And yes budm, a bad solder joint would have similar symptoms. Thanks for all you do out here!

[hitz]

Re: (again) AL2216W - 15s to black

Thank you both so far. I thought I had an old scanner, but I can't find it. There would've been a CCFL nearly same sized in it. So I just ordered one for less than 5€, if it works it would be a cheap repair. Hope the part is delivered before the weekend. I'll report in any case.

[hitz]

Re: (again) AL2216W - 15s to black

So, it took a little longer than expected. The dealer I first tried sent the wrong part, so I had to choose another one. He delivered the correct CCFLs today.

While disassembling the display enclosure, I recognized one of the old CCFLs is burnt (black spot 1cm from the end). There seem to be high temperatures during use: the clear pane hat some brown spots on its edge. So I replaced both CCFL, soldered the old connectors to it, tested it: IT WORKED!
So I reassembled it, and took the picture attached. Sorry for not documenting the single steps, but I think there are som good tutorials around.

Thank you all for pointing me in the right direction. I wish you all the best for 2014!

[Lumberjack777]

Re: (again) AL2216W - 15s to black

Great to hear. Another monitor saved from the landfill. Thanks for the feedback. Happy New Year to you too!