Acer AL2423W

[Gilfar]

Symptoms:

When power is switched on the power led blinks green once (signal color). I'm not sure it should behave like that under normal conditions.
During the 1st cold boot the monitor works fine after recapping, however after you turn it off it no longer shows anything. It starts to show the acer logo for 0.5 s and blinks once with lamps. After that the screen stays black, no indication of backlight and the signal led stays green (signal detected).

Done so far:

changed all bad caps (already leaking caps on inverter board)
checked pico fuses ~1 Ohm, however my current multimeter isn't very accurate at such low resitance
monitor works every cold boot (no power for some hours)


Any ideas based on symptoms what to check to at least narrow it to one of the pcbs ? I've only got very basic experience with electronics, so please be precise.
I'll get some images once I find my camera power cable.

[budm]

Re: Acer AL2423W

Once we get to see the pictures then we may be able to help.

[selldoor]

Re: Acer AL2423W

Symptoms:

monitor works every cold boot (no power for some hours)

When cold booted how long does it stay on for?
and is this with a source connected.

This is how to post pics
please post good clear pictures of the whole chassis, and then pictures of each board, front and back (in the same orientation) and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed

https://www.badcaps.net/forum/attach...7&d=1280167246

https://www.badcaps.net/forum/attach...6&d=1280167246

https://www.badcaps.net/forum/attach...4&d=1280167246

[Gilfar]

Re: Acer AL2423W

After the exchange of capacitors on the inverter board and 1 on logic board it's working for very long time with source, so normal operation with image showing and backlight working. I've only tested for ~2h, but I suppose it could work till I switch it off.

I'm sorry for the quality and cutting of the images , but as I took those photos I learned my camera doesn't support macro mode very well and the whole images were too blurry.
I can try to retake them at better lighting during the day.

I'll get to unscrewing the power and logic board again to get more pictures if those are acceptable.

[selldoor]

Re: Acer AL2423W

Were the caps you put in the inverter board a good make?
Have you checked your soldering for a cold solder joint.
Check the transformer joints with a magnifying glass.

When it comes on in fault mode - no back light but green led can you see a very dark image on the screen of what the pc is showing. Perhaps shining a flashlight at an angle
will help with this.

Seems an unusual fault - may be difficult to trace.

[Gilfar]

Re: Acer AL2423W

Yes those were Sanyo / Rubicon. I've checked their capacity before soldering.
Yes, I even brought them to a friend who's doing electronic repair and he double checked all solder joints, because some may have been not the best quality before.
I checked the transformers joints on the inverter board and they all look fine on the front, as the pcb is multi layer I can't check on the other side.

I tried shining a flashlight and watching from different angles, but it's pitch black. Does this mean that the power is cut from the panel after the unsuccessful try ? I checked for the signal detection and it instantly picks it up when a cable is inserted, however it takes ~5 seconds when I unplug it to change to orange (no signal) color.

The current fault may be caused by the bad capacitors, I should have replaced them before the monitor when really bad.

[budm]

Re: Acer AL2423W

OK, so when it goes dark, do you still get 24vdv on those green PICO fuses on the inverter board. We need to find out what signals you lost when it goes dark: the 24v power from the power supply, or the bl_on signal from the main board.

[Gilfar]

Re: Acer AL2423W

I checked them and there's no power 0 VDC on any of those PICO fuses on the inverter board.

[selldoor]

Re: Acer AL2423W

We are going to need pictures of the front and back of both boards.
Good light but no flash is needed.