ACER AL2017.....not working...Led comes on....with-flashlight can see image

[Welchs101]

I have an ACER AL2017 a friend brought over for me to look at. I am hoping to fix this monitor so that i can fix another monitor that i have been working on for a long time. This monitor has a power supply board very similar to the westinghouse power supply board shown in this thread

https://www.badcaps.net/forum/showth...3&page=1&pp=20

In this thread above caps, power-fets and fuse were replaced. I did the same.


When i power on the monitor the lamps DO NOT COME ON.

The green LED light does come on.

Also, using a flashlight directed towards the screen, i can see the image.

Its just that the lamps wont turn on.

Note: I have checked the LAMPS using another monitor and they work fine.

Sounds like an inverter problem but i am not sure how to isolat the problem.

Any ideas on what to measure to figure this one out?

[PlainBill]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

I have an ACER AL2017 a friend brought over for me to look at. I am hoping to fix this monitor so that i can fix another monitor that i have been working on for a long time. This monitor has a power supply board very similar to the westinghouse power supply board shown in this thread

https://www.badcaps.net/forum/showth...3&page=1&pp=20

In this thread above caps, power-fets and fuse were replaced. I did the same.


When i power on the monitor the lamps DO NOT COME ON.

The green LED light does come on.

Also, using a flashlight directed towards the screen, i can see the image.

Its just that the lamps wont turn on.

Note: I have checked the LAMPS using another monitor and they work fine.

Sounds like an inverter problem but i am not sure how to isolat the problem.

Any ideas on what to measure to figure this one out?

If memory serves, this board is notorious for shorted inverter transistors and a blown fuse. The fuse is a smt style on the back of the board - look for the M in the inverter area. Also, replace all electrolytic caps with the usual exception.

PlainBill

[Welchs101]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Yep, i already replaced the inverter , fuse and a few caps.

[seanc]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

I think that board looks pretty similar to a board I have in my Viewsonic VX2235M (or similar model)

[Welchs101]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

ok. I looked up the model you suggested not much in the way of repair or troubleshooting info. But thanks.

[seanc]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Oops, it's VX2235WM, here's a good thread for pictures: https://www.badcaps.net/forum/showth...light=vx2235wm

[Welchs101]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

the original power mosfets that were in this board had shorts between two of the legs. The part number for the original power fets were "40T03GP". I read on the bad caps forum that an equivalent part to use for this was the following:

http://search.digikey.com/scripts/Dk...863-NTP45N06LG

The badcaps thread which mentioned this part equivalency is shown here:
https://www.badcaps.net/forum/showthread.php?p=81893

For this monitor i was asked to measure the resistance between the leads of the power fet:

PowerFet1:
Resistance between Pin1(Red probe) and Pin2(black probe):open....resistance too high to measure

Resistance between Pin1(black probe) and Pin2(red probe):1.488MegaOhm

Resistance between Pin1 (red probe) and Pin3 (black probe):open....resistance too high to measure

Resistance between Pin1 (black probe) and Pin3 (red probe):starts out at 3.4MegaOhms and keeps increasing

Resistance between Pin2 (red probe) and Pin3 (black probe):4.43 Meg ohms

Resistance between Pin2 (balck probe) and Pin3 (red probe):2.7Megaohms and increases


PowerFet2:
Resistance between Pin1(Red probe) and Pin2(black probe):starts at 3.7Megohm and increases

Resistance between Pin1(black probe) and Pin2(red probe):3.33MegaOhm

Resistance between Pin1 (red probe) and Pin3 (black probe):3.64megohms

Resistance between Pin1 (black probe) and Pin3 (red probe):3.1megohms

Resistance between Pin2 (red probe) and Pin3 (black probe):3.96megohms

Resistance between Pin2 (balck probe) and Pin3 (red probe):2.75Megaohms and increases



Resistance between Pin1 of fet1 and pin1 of fet2: 5.8megohms

[frankNstein]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

This looks like a DAC-19M005 board if it is check F200 and see if it is open again.

[Welchs101]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Hi,

I already replaced the fuse 200. I replaced several caps and the power fets.

Current status of monitor:
Power LED light comes on. I can see the image on the screen with the help of a flashlight. I have also checked the ccfls........they appear to be good.

[frankNstein]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

The fuse is probably open again. I have one of these boards with the same problem.

[PlainBill]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Hi,

I already replaced the fuse 200. I replaced several caps and the power fets.

Current status of monitor:
Power LED light comes on. I can see the image on the screen with the help of a flashlight. I have also checked the ccfls........they appear to be good.

Things to check:

1. The fuse. If it is open, don't replace it yet. Instead use a #1157 bulb (automotive tail light).

2. The state of the BL_ON line. It should be close to 0 volts.

3. Is power getting to the inverter controller?

PlainBill

[Welchs101]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

I checked the fuse........IT IS OPEN!

I bought a bulb but i dont know if it has the same voltage and current rating. The one i have is a Sylvania #921 (12.8V, 17.9W). Would this work? If not i will buy the one you mentioned in your thread.

You said the state of the BL_one line should be 0V......where do i measure this?

Is power getting to inverter controller...........Is the inverter controller the BIT3713 device?

[PlainBill]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

I checked the fuse........IT IS OPEN!

I bought a bulb but i dont know if it has the same voltage and current rating. The one i have is a Sylvania #921 (12.8V, 17.9W). Would this work? If not i will buy the one you mentioned in your thread.

You said the state of the BL_one line should be 0V......where do i measure this?

Is power getting to inverter controller...........Is the inverter controller the BIT3713 device?

That bulb will work, perhaps better than the one I suggested. Now the idea is to use that to replace the fuse (temporarily) while you figure out what is causing the fuse to blow.

PlainBill

[Welchs101]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Any suggestions on how to figure out what is causing it to blow while the light is on? I mean what do i look for? Do i touch comonents to see which one is getting hot or do i try and measure voltages?

[PlainBill]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Any suggestions on how to figure out what is causing it to blow while the light is on? I mean what do i look for? Do i touch comonents to see which one is getting hot or do i try and measure voltages?

I'd do the 'touch tests' first - CAREFULLY!!!

PlainBill

[frankNstein]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Check Q202 and see if it is open.

[Welchs101]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

will do. Right now i am fighting a really big fire........my A/C is not working. Soon as i get it fixed.......i will get back on this monitor.

Thanks for all the suggestions!

[smason]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

will do. Right now i am fighting a really big fire........my A/C is not working. Soon as i get it fixed.......i will get back on this monitor.

Thanks for all the suggestions!

A/C??? WTF? It's April! We're months away from A/C season.

[Welchs101]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

A/C working......at least for now. Guess what........the cause was a bad "start" capacitor.

Anyway, back to monitors.

I checked Q202........but to be honest i am not sure what this device is and what it should measure. I am enclosing a pic of this device (Q202) ........it has markings on it of "14".

I am hoping to try the "light bulb" test later today.

[PlainBill]

Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

A/C working......at least for now. Guess what........the cause was a bad "start" capacitor.

Anyway, back to monitors.

I checked Q202........but to be honest i am not sure what this device is and what it should measure. I am enclosing a pic of this device (Q202) ........it has markings on it of "14".

I am hoping to try the "light bulb" test later today.

Use the standard tests for a transistor. Label the leads - lower left '1', top center '2', lower right '3'. Measure resistance 1-2, 1-3, 2-3; all should read > 100 ohms.

Switch to the diode test range and do these tests. Black lead goes to the first terminal, red lead to the second. You should get a reading of about .5 volts on only two of the six tests. The others should read open.

1 2
1 3
2 3
2 1
3 1
3 2

PlainBill