Acer AL1916W, can't find the problem

[Davi.p]

Re: Acer AL1916W, can't find the problem

What is tricky? he has swapped "the" with "that"..

[selldoor]

Re: Acer AL1916W, can't find the problem

I hope it'll work.

So do I
- This is the tricky bit
" Pls confirm the port that whether is suitable to your machine or not before you buy it."

[Phoenix83]

Re: Acer AL1916W, can't find the problem

Hi everybody.

Whereas it is probably a problem in the mainboard, so I ordered this:

http://www.ebay.com/itm/LVDS-NTA93A-...tem337d84db25]

has anyone have experience with this?
I hope it'll work.

[viziks]

Re: Acer AL1916W, can't find the problem

Hi everybody.
Have in my hands monitor AL1916W, but is broken. Both leds (green and amber) lighting at the same time and that's all. I changed the Electrolytic capacitors on the power board. Seems it works, because on the connector to the logic board I measured all the tensions, but slightly different. On the PCB is written +13,8V I measured 14,08 and is written +5V measured 4,97V. I don't know if it can be the problem, don't think so. On the logical board measured 3,29V on both Voltage regulators ABF646 (U6, U7) marked with red circle on the pic. I do not know whether to be both 3.3 V, or one of them is wrong. I have the service manual but for a different model and there is one 3,3V and the other one 1,8V...

Also the inverter transformer is too noisy. I need to build a tester to check it out.

I'm sorry for my english

Hello guys! If both led's are lit there is almost 99% chance that main board is defective
Before making any electronic tests in Inverter section for "No Display" problem confirm that you can switch on/off using power button.Only if power button operates the power led should you troubleshoot the inverter section .
If no power led glows then troubleshoot only power section or main board.

[Phoenix83]

Re: Acer AL1916W, can't find the problem

I'll try to measure all transistors, if I can find out the types... But not now, now I'm going to the pub to take some beers with friends.

[Davi.p]

Re: Acer AL1916W, can't find the problem

I don't have saw it? I have already get the service manual on electrotanya at address
, but i think you'll for sure end to search for another main board. Unfortunately SM don't say all the truth i think, it's strange it don't tell about a service menu, so try to power up the monitor with power+ another button pressed, this can show the service menu. it's a desperate try since your monitor seems stuck in a non working state, seen the leds all lit, your firmware can be corrupt and you can try to search firmware data and reflash it if your monitor recognizes it but when never you'll find it?

[Phoenix83]

Re: Acer AL1916W, can't find the problem

I sent inquiry about this manual, directly to the Acer service center. They will certainly have it. We'll see the response...

[selldoor]

Re: Acer AL1916W, can't find the problem

You will be very very lucky if you find a sm.
We often get to this point and a new board is the only solution. It is often impossible to identify those small transistors and hard to find a faulty one unless it is burnt. Takes lots of time and sometimes you can pick up a board cheaply.

[Phoenix83]

Re: Acer AL1916W, can't find the problem

Hi
I solded one wire with resistor directly to the pin9 and other wire to the pin15. Then I touched the resistor with the wire for a second. It seems the backlight works. Now I have to somehow find out a problem on the main board. Probably I start with the transistors. Maybe one of SMD is bad. Hope the scaler is OK. But first I have to find the SM.

[budm]

Re: Acer AL1916W, can't find the problem

@1K with 5VSTBY, the maximum allowed current will be only 5mA, the B-E junction of the transistor or the LED inside the Opto can take more than that. 33K will be way to high and may not be enough to bias on the transistor or light up LED.

[Rtech]

Re: Acer AL1916W, can't find the problem

I have used a 1K resistor many times with no problem at all.as I am sure many others have, and one post saying it is wrong, is not proof that that is the case.

[Davi.p]

Re: Acer AL1916W, can't find the problem

I was reading a recent post and found that placing a 1k only resistor to BL_ON maybe not good, in fact i was unsure about it, i followed others.. sorry.. in that post has come out that a right resistor is around 33k, you can use a trimmer (i don't know trimmer values, maybe 33k??), 1k can damage your chip maybe, and 820ohm more.. or use a 3v battery between 2 pins.

[Davi.p]

Re: Acer AL1916W, can't find the problem

how do you have connected the blon signal, 5v and resistor? It's strange, are them firmly connected?

[Phoenix83]

Re: Acer AL1916W, can't find the problem

Here's the pics ot the logic board. There are more, and at the maximum resolution that my camera supports.


[img=http://img217.imagevenue.com/loc972/th_458773854_P1110925_122_972lo.JPG]
[img=http://img146.imagevenue.com/loc23/th_458859613_P1110926_122_23lo.JPG]
[img=http://img234.imagevenue.com/loc593/th_458941898_P1110927_122_593lo.JPG]
[img=http://img221.imagevenue.com/loc1190/th_459020857_P1110928_122_1190lo.JPG]

[Davi.p]

Re: Acer AL1916W, can't find the problem

I remember that the switch board shows a dual led lit, it's not normal i think, the problem is more probably in the mcu, after that why backlight flashes i don't know..

[selldoor]

Re: Acer AL1916W, can't find the problem

Hurray - as you say something works though flashing may not be enough!!!
Anway did you see this
http://mvptek.koreasme.com/en/produc...uct_04_03.html
looks like pinout for the IC.
If as we think it is just not getting a BLON signal - how about trying to trace pin 15 back -may just be one of those little switching transistors stuck.
Can you post a better picture of the part of the logic board with pin 15 and going across

[Phoenix83]

Re: Acer AL1916W, can't find the problem

So I joined pin 9 to pin 15 through a 820ohm resistor. Backlight started flashing. At least something works. I need to find the SM for model with RTD2533V scaler. Some manuals I have found but they are all with TSUMs

[budm]

Re: Acer AL1916W, can't find the problem

If the main board BL_ON line is stuck LO, then you have to disconnect that line otherwise it will keep that force on voltage to be low.

[selldoor]

Re: Acer AL1916W, can't find the problem

Its either the resistor OR the battery - I ask if people have either but they are used differently but for the same purpose.

Thinking is that the main board is not sending a signal to the power supply to switch on so we reproduce that.
The signal is usually 3v so whet you do is disconnect the the main board
and connect a 500 or 1kohm resistor from the 5v pin on the connector
to the on/off pin (looks to be pin 15). If you have the lamps connected then
when you switch on/plug in the power supply they may light or at least flash.

Sometimes it is necessary to also jumper the 5v to the BL adj (pin16)

[Davi.p]

Re: Acer AL1916W, can't find the problem

Have you forgot? I've told it in the past 10 posts