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Old 03-31-2010, 08:29 AM   #1
Welchs101
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Default 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

http://www.badcaps.net/forum/showthr...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?
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Old 03-31-2010, 10:36 AM   #2
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Default Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Quote:
Originally Posted by 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

http://www.badcaps.net/forum/showthr...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
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For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.

Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.

Last edited by PlainBill; 03-31-2010 at 10:39 AM..
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Old 03-31-2010, 10:41 AM   #3
Welchs101
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Default Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Yep, i already replaced the inverter , fuse and a few caps.
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Old 03-31-2010, 12:40 PM   #4
seanc
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Default 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)
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Old 03-31-2010, 02:51 PM   #5
Welchs101
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Default 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.
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Old 03-31-2010, 03:03 PM   #6
seanc
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Default Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Oops, it's VX2235WM, here's a good thread for pictures: http://www.badcaps.net/forum/showthr...light=vx2235wm
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Old 03-31-2010, 06:48 PM   #7
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Default 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:
http://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
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Old 04-01-2010, 06:17 AM   #8
frankNstein
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Default 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.
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Old 04-01-2010, 06:26 AM   #9
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Default 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.
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Old 04-01-2010, 08:16 AM   #10
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Default 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.
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Old 04-01-2010, 09:23 AM   #11
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Default Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Quote:
Originally Posted by Welchs101
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?

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Old 04-04-2010, 10:39 AM   #12
Welchs101
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Default 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?
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Old 04-04-2010, 06:44 PM   #13
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Default Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Quote:
Originally Posted by Welchs101
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.

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Old 04-04-2010, 06:57 PM   #14
Welchs101
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Default 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?
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Old 04-05-2010, 05:39 AM   #15
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Default Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Quote:
Originally Posted by Welchs101
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!!!

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Old 04-07-2010, 04:22 PM   #16
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Default Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Check Q202 and see if it is open.
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Old 04-07-2010, 04:50 PM   #17
Welchs101
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Default 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!
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Old 04-07-2010, 09:11 PM   #18
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Default Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Quote:
Originally Posted by Welchs101
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.
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Old 04-08-2010, 05:42 AM   #19
Welchs101
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Default 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.
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Old 04-08-2010, 07:31 AM   #20
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Default Re: ACER AL2017.....not working...Led comes on....with-flashlight can see image

Quote:
Originally Posted by Welchs101
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

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