Dell LCD 1905FP Problem

[abbas101]

My LCD Monitor 1905FP display is getting pink fluctuating band from its left side and display loose its sharpness. All other controls are working perfectly. I change VGA cable, CPU and I am sure it is from inside the monitor. I also perform factory reset. Following pics may explain the problem. Please advice.

[Ritalin]

Re: Dell LCD 1905FP Problem

I would have said that it's a backlight issue cause the pinkish hue is a sign of it, but I thought it usually affects the whole screen and not just a section like that. How long has it been like that?

[jetadm123]

Re: Dell LCD 1905FP Problem

It's probably time to take it apart. I don't think pressing any buttons on the front will clear that pink color problem. Please post some good clear foscused photos of the entire power board top and bottom. Also, a photo of the logic board would be good. Do not post photos inline, but use the "manage attachments" button.

[Scenic]

Re: Dell LCD 1905FP Problem

at least i'm not the only one with total chaos on the desktop

this looks like either bad caps on the lcd controller board or a flaky connection of the LVDS cable (the one going from the LCD controller board to the panel)

[abbas101]

Re: Dell LCD 1905FP Problem

I would have said that it's a backlight issue cause the pinkish hue is a sign of it, but I thought it usually affects the whole screen and not just a section like that. How long has it been like that?

It is over one week

[abbas101]

Re: Dell LCD 1905FP Problem

It's probably time to take it apart. I don't think pressing any buttons on the front will clear that pink color problem. Please post some good clear foscused photos of the entire power board top and bottom. Also, a photo of the logic board would be good. Do not post photos inline, but use the "manage attachments" button.

I will post pictures in a day time. Thanks

[abbas101]

Re: Dell LCD 1905FP Problem

It's probably time to take it apart. I don't think pressing any buttons on the front will clear that pink color problem. Please post some good clear foscused photos of the entire power board top and bottom. Also, a photo of the logic board would be good. Do not post photos inline, but use the "manage attachments" button.

I am including pics. On visual inspection I didnt notice any burn out component or suspicious capacitor. There was some dust and dirt accumulated which I cleaned. What should be my next step?

[abbas101]

Re: Dell LCD 1905FP Problem

at least i'm not the only one with total chaos on the desktop

this looks like either bad caps on the lcd controller board or a flaky connection of the LVDS cable (the one going from the LCD controller board to the panel)

I have posted few pics. There are hundred of tiny components on controller board. Is it possible to check these components on board without removing them. Sharing of your experience will be highly appreciated.

[Th3_uN1Qu3]

Re: Dell LCD 1905FP Problem

Clean all connectors with isopropyl alcohol (be careful not to spill it onto the panel!) and see if it still does it. That looks like a bad connection between display cable and panel OR it could be a problem with the panel electronics. If it's the panel it's not fixable.

[retiredcaps]

Re: Dell LCD 1905FP Problem

1) The bad news. There are tons of Capxon caps on both the power and logic board. Capxon has less than a steller reputation here.

Capacitors die from age, heat, and shoddy build quality. Capacitors DO NOT have to be visibly bloated in order to bad. They can be out of tolerance uF (a 1000uF measures 20uF) and/or have high ESR (ohm). A multimeter will be insufficient to test for ESR. For that you need an ESR tester which costs between $50 and $300.

Most members here will recommend that you replace ALL capacitors with reputable brands from reputable sellers. Brands like Rubycon, Panasonic, and United Chemicon are suggested. A list of recommended caps can be found at

https://www.badcaps.net/forum/showthread.php?t=2280

The cost of replacing all the Capxons is something for you to decide. No guarantees that the caps are causing the problem as it may be the panel.

However, before you replace them, you can do the following tests below.

2) If you have a multimeter, measure the voltage regulator I200 on the logic board. It is a 3.3V regulator so the output pin should be 3.3V.

3) Measure I313. It looks like a 18 type of part number? Look at the part number and find the datasheet. Then test for DC voltage and compare it to the datasheet.

4) On the connector from the power board to the logic board, measure and list the DC voltages on all the pins. Note if the voltages are steady or fluctuating.

[gregory_dubb]

Re: Dell LCD 1905FP Problem

Well, it's not backlight problem for sure. Is it temperature or time related? If not, then it's definitely video processing problem either within video card or main pcb, not the T-con.

[jetadm123]

Re: Dell LCD 1905FP Problem

Nice photos! Posts #9 and #10 are good ideas. Also, have you verified that the video cable connecting your monitor to your computer is good?

[abbas101]

Re: Dell LCD 1905FP Problem

Nice photos! Posts #9 and #10 are good ideas. Also, have you verified that the video cable connecting your monitor to your computer is good?

Yes. I check cable. It was ok.