acer AL2016W control board problem

[Kevin O'Henly]

This is my first thread and here goes.

The power-on led does not light up, no display, no back lighting, no "power on" LED signal.

I checked the power board (ILP-001) and it is supplying all the correct voltages to the other 2 boards: compact fluorescent lamp (CFL) driver board and display controller board on seperate cables.

The "on/off" signal from the display controller board (ILIF-006) is at ground. This signals an "off" or fault mode I suppose.

When I pop the "on/off" wire (green) from the cable connector between the power board and controller board and connect it to 5Vdc through a 2K ohm resistor (to limit current) the compact fluorescent lamps illuminate. They go out again in about 5 sec.s. My guess is that the "on/off" signal normally oscillates in "on" mode. This seems to suggest that the compact fluorescent lamp (CFL) driver board is functional.

I hooked-up the VGA signal and started looking at the display controller board.

Since the voltages are power supply voltages to the controller are correct I then checked the signal at the micro-controller chip crystal and there does not seem to be any oscillations there.

This suggests that the controller is at fault/dead.

I have not got a substute display controller so I am going to need some help to keep this one out of the recycling bin.

[dondrusco]

Re: acer AL2016W control board problem

There are 3-4 voltage regulators at control board.
(something like https://www.badcaps.net/forum/attach...chmentid=12463)

Post a picture of this board and measure voltages.

[PlainBill]

Re: acer AL2016W control board problem

This is my first thread and here goes.

The power-on led does not light up, no display, no back lighting, no "power on" LED signal.

I checked the power board (ILP-001) and it is supplying all the correct voltages to the other 2 boards: compact fluorescent lamp (CFL) driver board and display controller board on seperate cables.

The "on/off" signal from the display controller board (ILIF-006) is at ground. This signals an "off" or fault mode I suppose.

When I pop the "on/off" wire (green) from the cable connector between the power board and controller board and connect it to 5Vdc through a 2K ohm resistor (to limit current) the compact fluorescent lamps illuminate. They go out again in about 5 sec.s. My guess is that the "on/off" signal normally oscillates in "on" mode. This seems to suggest that the compact fluorescent lamp (CFL) driver board is functional.

I hooked-up the VGA signal and started looking at the display controller board.

Since the voltages are power supply voltages to the controller are correct I then checked the signal at the micro-controller chip crystal and there does not seem to be any oscillations there.

This suggests that the controller is at fault/dead.

I have not got a substute display controller so I am going to need some help to keep this one out of the recycling bin.

A similar problem occurred with another Acer monitor. As dondrusco said, post pictures of the logic board. In the other case, the problem was the reset controller (3 pin device) on the logic board.

PlainBill

[Kevin O'Henly]

Re: acer AL2016W control board problem

There are 2 triode devices on the controller board: U101 & U102 as located in the picture.

Voltages are measured with respect to ground: CN801, pin 6.

U101 pin 1 is at 0v
U101 pin 2 & tab are at 1.7vdc
U101 pin 3 is at 3.2vdc

U102 pin 1 is at 0v
U102 pin 2 & tab is at 2.4vdc
U102 pin 3 is at 4.3 vdc

[Kevin O'Henly]

Re: acer AL2016W control board problem

The acer widescreen is now working great!!!
When I got back to the bench (kitchen table) after posting, it was working.

The touch of my analogue meter probe or magic of the season?

Cheers and thank you.

[PlainBill]

Re: acer AL2016W control board problem

The acer widescreen is now working great!!!
When I got back to the bench (kitchen table) after posting, it was working.

The touch of my analogue meter probe or magic of the season?

Cheers and thank you.

"Problems that go away by themselves come back by themselves." Bill Farrel (no relation to the actor).

PlainBill

[dondrusco]

Re: acer AL2016W control board problem

The acer widescreen is now working great!!!
When I got back to the bench (kitchen table) after posting, it was working.

The touch of my analogue meter probe or magic of the season?

Cheers and thank you.

Capacitors do that. Turn monitor off for 10 minutes and try turn on again. I bet you, that it will not start. You can see, how voltage increases.
That big one capacitor near U101 and two bigger near U102 may cause this problem.

[Kevin O'Henly]

Re: acer AL2016W control board problem

You're right, of course.

It unsettled me to find the problem having resolved itself.

I used the oscillator, oscilloscope & resistor method of checking for ESR on those caps and it's all good; I think. Time will tell.

I looked for foil opens in that area and applied bending torque to the controller board. Nothing poped out or off. These problems can be tricky.

I resoldered all the caps just in case.

24 hrs. now and not a power up fault; yet.

Hugh!

I realy like the folks at this blog. Your stick-to-it-ness. is commendable.

I hope to contribute. ...when I get a track record on solving these types of problems.

Cheers