Acer AL1917 headache has returned

[greggmh123]

Hello!

The problem detailed in this thread in Sept. 2012 has returned on one monitor: https://www.badcaps.net/forum/showthread.php?t=22517. The last step noted in page 2 worked since Sept 2012 and just started acting up again.

It is an Acer AL1917 C, version AL1917Cd, model ET.1917B.0DC, built in February 2007. The power board has # 715G1823-2, the video board has # 715G2227-1-AC, and the "button board" (power, volume, menu, etc) is # 715G1944-2-AC.

It will work for several minutes, then turns off. It will not turn back on again unless I disconnect the power cord and reconnect it. It is not just the "2 seconds to black" thing I have read about here. It turns off completely. I can have the monitor cable disconnected and only have power, then let it sit for a while and it will power cycle all by itself. I hear the speakers pop, the green power light comes on, the logo comes on, then it goes back off again. The cycle repeats perhaps five seconds later and keeps doing it until I pull the power cable. Other times, that cycle may happen every 30 minutes.

I have replaced all the caps on the power board and audio board except for the 450V 100uf, only because no local store has one. They all tested good with my ESR meter.

On my last repair attempt, I suspected the power button board, and this time it had the volume menu pop up on screen and not go away for a couple of days. I found one power button that had 70 ohms of resistance when it should have been open, and I replaced that one. The other buttons tested good. I am at a loss as to what to do next, other than buy a new monitor.

I hate giving in and would like to find the root cause. Does anyone recognize these symptoms...and have a recommended repair?

Gregg Hill

[selldoor]

Re: Acer AL1917 headache has returned

I cant see what the last step was - can you just say what you did to fix it.

If you still have the other monitors can you swap one board out at at a time then we know which board to work on.

[greggmh123]

Re: Acer AL1917 headache has returned

selldoor,

The last step in Sept 2012 was "I took all three boards from the problem monitor and put them into the good monitor and it worked perfectly for days. I took all three of the good monitor's boards and put them into the problem monitor, and it too worked fine.

Finally, I installed the power board from the problem monitor back into it, but used the audio and video boards from the good monitor in that problem monitor. I took the problem monitor's audio and video boards and put them into the good monitor along with its original power board.

Everything has worked fine for a week."

It ended up working fine since Sept. 2012 until a week or two ago.

I was hoping that someone might recognize the symptoms. Rather than tear down two monitors and leave my wife with nothing to use, I will have to buy new monitors. Now I have to find a good brand that still comes in 4:3 ratio so that she can still have them fit on the LCD arm and have resolution that she can see decently (1280 x 1024).

Gregg Hill

[Davi.p]

Re: Acer AL1917 headache has returned

I can't see my post i rewrite it.. i'm not an expert troubleshooter anyway some test could take longer time so i take the thing to the wide, why don't you try to set up a test bench with mon. dismantled and hooked to a pc, switch them on then detach the button board and see if the problem persist? If no, while ON connect the button bd and see what happens..

[greggmh123]

Re: Acer AL1917 headache has returned

Well, I took the problem monitor and set it on a desk, popped off the back, and hooked up a laptop to it to activate the screen. As usual, it worked fine for a while, then started the off/on cycle again. When it came back on, I quickly disconnected the power button board 715G1944-2-AC and it stayed on for hours. If I reconnect the board, it may stay on for an hour, or a few seconds.

Does that really mean that the board is bad, or could it be something else in the circuits that connect to board?

I don't want to inconvenience my wife by taking apart her good monitor. I wish I knew what to test on this board. I suspect it's the board itself, because when the problem happens, NO button on the board responds. I will start looking for one on ebay, etc.

Gregg

[Davi.p]

Re: Acer AL1917 headache has returned

Now since the problem is already not evident, one test could be desolder the power on button and solder 2 wires instead, see what happens (u must short circ. them for an instant to switch monitor on)

[greggmh123]

Re: Acer AL1917 headache has returned

I had already replaced the Volume Up button due it showing 70 ohms when open, so I removed the remaining four buttons, including the power button. The monitor has stayed on for a couple of days so far. I have it sitting with a new power button inserted but not soldered yet. I will see how long that lasts.

Gregg Hill

[greggmh123]

Re: Acer AL1917 headache has returned

I soldered the new button switches and put it back together. I think it is fixed this time.

Thank you to everyone who helped with this long saga!

Gregg Hill