Viewsonic VX2035WM Turns on for a few seconds then goes black

[Welchs101]

I have a Viewsonic VX2035WM.

Turns on for a few seconds then screen goes blank. Once screen goes blank if you take a flashlight and shine it on screen you can still see the faint image on the screen.

Normally, I check the bulbs but this unit has an unusual connection scheme. I am hoping someone can tell me how to hook it up so i can test the bulbs.

Bulbs are located at the top and bottom of the screen as usual.
Bottom: Has two connectors. One connector has two wires (Both white) and one connector has 4 wires(dark-blue, black, light-blue, pink)
Top: Has two connectors. One connector has two wires (Both white) and one connector has 4 wires(dark-blue, black, light-blue, pink)


If i wanted to test the bulbs i need to know which wires go to the individual bulbs and i am not sure which wire goes where..........

can someone help?

[mockingbird]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

Get rid of those Hermei and Elite caps I see there on the PCB and replace them with something suitable.

[Welchs101]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

Thanks.

I do plan on looking at the caps in more detail but before i just start removing caps I like to try the simple things like
1)testing bulbs
2)testing transformers
3)testing mosfets

I am at the beginning .....trying to test the bulbs.

Any idea on how to test the bulbs? I am just not sure which wires to test?

[PlainBill]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

Thanks.

I do plan on looking at the caps in more detail but before i just start removing caps I like to try the simple things like
1)testing bulbs
2)testing transformers
3)testing mosfets

I am at the beginning .....trying to test the bulbs.

Any idea on how to test the bulbs? I am just not sure which wires to test?

Trace the outputs from the transformers. On the large connectors it looks like pins 1&2 drive one CCFL and 4&5 drive another. Of course, the small connector drives a third CCFL.

PlainBill

[Rtech]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

Have seen thos sort of set up occasionally,and you may well find that both CCFL Reflector channels hold qty 3 lamps each,so just use a test CCFL ,as normal to test the lamps individually.

[Welchs101]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

Update:

I was able to test all the lamps in the monitor and all seem to be working fine.

One lamp is the white connector. Note: "Hot" wire is slightly larger in diameter.

One lamp is using Pink and Black wires. Note: "Hot" wire is slightly larger in diameter.

One lamp is using Light-blue and Dark-blue wires. Note: "Hot" wire is slightly larger in diameter.


I tested ALL 6 lamps and ALL seemed to be working fine.

I guess the next step is to check the transformers. I will let you know what i find.

[Uranium-235]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

thats the exact monitor I have in my posession right now to try and fix for a friend. but my picture goes black, and the backlights stay on. kind of the opposite of yours

if you can't get this fixed, I woulden't mind buying that video board off you

[Welchs101]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

ok, so i have not had a lot of time to work on this but i found a little time this morning.

I checked the transformers and the chips (see enclosed photos). I did not see anything "unusual". I know that does not mean they are good........i need to report the actual measured values and i will....once i remeasure again and record data.

I am enclosing pics of the back of the board in the inverter area.....which is where i think the problem might be............or could be the caps.........have not checked those with a cap meter yet since i have to borrow one from a friend.

I wanted to get you guys opinion on what i should check next and how.

[sabre504]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

Similar setup to the Samsung 215 had one that would come on then go off turned out to be 1 transformer ( top one )

[Welchs101]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

I finally got around to posting the measurements on the transformers. They ALL measured the same so either they are ALL bad or ALL good........i think.

See enclosed pic to see pin identifications.

For all transformers (T1 - T6):
Pin1 to Pin2: Open
Pin2 to Pin1: Open
Pin1 to Pin3: 1.1Kohm
Pin3 to Pin1: 1.1Kohm
Pin1 to Pin4: 2.7Megohm
Pin4 to Pin1: 2.7Megohm
Pin1 to Pin5: 2.7Megohm
Pin5 to Pin1: 2.7Megohm
Pin1 to Pin6: 2.7Megohm
Pin6 to Pin1: 2.7Megohm
Pin1 to Pin7: 2.7Megohm
Pin7 to Pin1: 2.7Megohm

Pin2 to Pin3,Pin4,Pin5,Pin6,Pin7: Open

[sabre504]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

Transformers seem ok (couldnt see your pic)

Caps would be the next thing

[sabre504]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

Could be the angle or trick of the light but the cap i have ringed seems slighty bulged .
Are there any under the heatsink plate ?

[alexanna]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

Transformers seem ok (couldnt see your pic)

Caps would be the next thing

Welchs, I don’t know where you are with your monitor, but it sounds like 2 sec to black.
I think I would also replace the capacitors to take one more thing out of the equation. Also
If you haven’t done this, try it.
Find a good CCFL from a 17” monitor, Hook up all but ONE of the CCFLs from your monitor.
Place the 17” in the remaining connector, power on the monitor dose the test bulb light or do the CCFLs stay on?
Repeat this on all of the other CCFL connectors.
This is going to try to identify a particular circuit that may not be working

[Welchs101]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

i have not tried any of the suggestion yet........i just realized i did not put the picture in my post this morning. so i am posting it now.

[Welchs101]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

i am posting a mag pic of the cap sabre504 thought was bulging. I think it was just the bad lighting. I am enclosing another pic........looks ok to me.

alexanna, i like your idea but i will have to create a "jig" that goes from the LCD i am trying to repair to an LCD bulb i know is good. may take a while as i am really busy these days but i will try.

[alexanna]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

^
Don't you have an LCD with a damaged or broken screen? You do enough monitors, they will come in really helpful in the future, Just remove the bulbs

[Welchs101]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

i do have some extra "bulbs" and i think i went through this exercise before but i need to find the "jig" i made. i have been very busy lately so i dont have a lot of time. this monitor is my neighbor's and i am trying to fix it for him.

thanks for the reply.

[Welchs101]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

In trying to hook up external bulb to monitor i am tyring to fix:
1) Recall that for this monitor there are 4 connectors. Two of the connectors look like what i would call the "two" wire standard connection. The other two are more "non-standard". For the standard two wire connections i can plug my other bulb into the non-working monitor. However, for the "non-standard" connector..........not sure how to handle these.

today i am going to a friends to borrow their esr meter so i can check the caps.

[alexanna]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

If you look at the end of the CCFL conector, where it plugs in to the inverter you will notice a square slot and on the top of it is a rectangular slot.
Push the lead of a small capacitor into the rectangular slot, this will release a tab on the metal connector and allow you to remove the wiring pigtail from the plastic connector. You can then install the wiring pig tail into the plastic connector your monitor is using. Just remember the orientation of the Hot and Return wires.

[Welchs101]

Re: Viewsonic VX2035WM Turns on for a few seconds then goes black

Had a little time this morning. THought i would try the last suggestion about replacing bulbs. Then i started to think about what it was i was doing and well i am not sure why i am doing.

I already tested the bulbs of the broken MOnitor. To see how i did this see enclosed picture. "Test already done"

It is proposed that i switchout the bulbs one at a time from the bad monitor to a good bulb/monitor. From what i read, i included a pic of what this test is to do as well. See enclosed pic "Test to do".

What i dont understand is what I will learn from this new test. Seems like i am just testing the "bulb". If this is the case then didnt i already do this.

Just trying to understand this "test to do" a little more because from what i know (which is obviously not much) it seems that i am testing the integrity of the bulbs in both cases.