Dell 2005FPW PS PROB AND VERT ROLLING

[bugmenot]

I have a dell 2005FPW that has 2 different problems.
the first is a power supply problem (I think). Nothing visibly looks bad but the power blinks on and off. Any ideas? (or a schematic?)
the second problem is a vertical rolling. If it were a CRT i would say the vertical hold circuit was shot. again, any trouble shooting ideas?

Any help appreciated.

[Toasty]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

>>Nothing visibly looks bad...<<
You have it open, correct?

If so, whose brand and series of caps?
Caps can look fine but internally they have failed.

I think the 2 problems are directly related. The rolling video is coming from a bad power supply.

Pics please.

Toast

[bugmenot]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

Here are some pictures,

PS board
http://h.imagehost.org/view/0249/40600001

http://h.imagehost.org/view/0300/40600002

and


Display board
http://h.imagehost.org/view/0158/40600003

[bugmenot]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

The caps are mostly Sam Young
no visible leakers or bulges

[Toasty]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

SamYoung, Samwha, Evercon all made by GSC from what I gather...

CRAP

Picture shows 2 caps of LXZ series. Don't see other markings... Why do pics have a yellow cast to them?

Nothing appears burnt or darkened. A good sign.

Discharge that mains cap before working on the board. A 2 watt 50k ohm or higher resistor across it should drain it safely and quickly. Check voltage across it to insure it is discharged before working on circuit.

Check the solder side for any cold joints or cracks in the area of the main filter cap and the bridge rectifier mounted on that L-shaped aluminum heatsink next to it. Also, check all the connections of those 6 backlight transformers for the same problem. If any of the joints looks suspicious, reflow them and check unit operation again.

Do you have any test equipment? Scope? ESR meter? VOM/DMM?

If not, and you're still having the problem, I'd start replacing the caps. You have a total of 10 there including the mains filter one. Should be doable for less than $20 including shipping.

If you need help finding cap replacements, post back with series and values.

Toast

[Krankshaft]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

Fluorescent lighting without a flash usually produces that yellowish hue.

As already said check and or replace secondary caps first also check the inverter transformer driver transistors. They'll be in close proximity to the transformers.

Put the video problems on hold for now improper supply voltage and bad caps can cause all sorts of strange things to happen in an otherwise properly operating circuit.

[billstvs]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

I have the same model with the rolling problem.
Narrowed it down to C637 470/16v on video/logic board.

[Toasty]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

Good info. How was the power supply looking in yours?

OP has not replied to questions posed and no posts in 6 weeks.

[billstvs]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

Good info. How was the power supply looking in yours?

OP has not replied to questions posed and no posts in 6 weeks.

Power supply looked good. No bulged or leaky caps. No cracked solder.
One cap checked bad on ESR meter, replaced it with no change in symptons.
Found bad cap on video/logic board by heating and cooling. ESR checked good on that one.

[Toasty]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

>>Found bad cap on video/logic board by heating and cooling.<<

Old school still works!! Hair dryer and a can of freeze spray.

Thanks for the info and Welcome to the forums!

Toast

[djbush2000]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

Folks. I had the same exact problem, same fix. C637 on logic board was defective. I replaced all the caps on the power board anyway. Monitor works fine now. The factory had substituted a cheap, smaller capacitor as the silkscreen template called for a larger one.

[goodguy]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

Have this same problem now except, I opened it using this link:
Disassemble Dell 2005FPW

Decided to do this as well since it was still open:
Back Light Fix





In this picture I circled the bottom part I was curious about, within the circle is a powdery substance, I don't know if its worth mentioning but I thought it's worth pointing out.

So When I closed it up after all this it no longer blinks on and off like it used to but remains on when I turn it on, and off when I turn it off but it doesn't project any picture.

I'm new so anyone can point me to where I can buy the CAPS I need to replace my old ones I would appreciate it as I am not very knowledgeable but I dab into things here and there, this wasn't bad.

Didn't feel the need to open a new topic with a similar issue.

[goodguy]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

Some weird 10 minute edit thing... so I have to post a new post cause I tried to edit my old one to add new helpful information...

Before I opened it, it made a long sound not too loud but almost like a dog whistle until it stopped the vert rolling, I also thought I heard some sizzling at least I thought it was where the power supply unit is but everything looks fine to my untrained eye.

[notaclue]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

I have the same 2005FPW with the vertical rolling problem, however, the C637 (KMG) and C6335 tested good (removed from board, digital meter went slowly from 19 to 13.30). To verify that I have the same problem, after 10 or 15 minutes of running the monitor without connection to PC, the rapid vertical rolling will stop and the display will be perfect (see floating Dell Color Bars). When plugged into a video source (PC) the vertical rolling starts and will not stop regardless of how long it is left on. Please let me know if this is similar to what those of you with the bad C637's experienced.

[vo_danh]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

>>Found bad cap on video/logic board by heating and cooling.<<

Old school still works!! Hair dryer and a can of freeze spray.

Thanks for the info and Welcome to the forums!

Toast

Can you please elaborate on this 'heating cooling' method. I recently obtained a 2005FPW when plugged in I only get power light and #1 flashing green. I opened it and caps look good on power supply. I can't see if they're bulging at the bottom.

[jetadm123]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

Can you please elaborate on this 'heating cooling' method. I recently obtained a 2005FPW when plugged in I only get power light and #1 flashing green. I opened it and caps look good on power supply. I can't see if they're bulging at the bottom.

Read this link about freeze spray:

https://www.badcaps.net/forum/showth...t=freeze+spray


Sounds like you have a non temperature related problem. Please post some photos per the link below and members can make suggestions on what to test. Also, be more descriptive on what you're seeing. Do you get a flash of light when you first turn it on, then the screen goes blank? With the monitor is on, if you hold a flashlight close to the screen, do you see an image?

https://www.badcaps.net/forum/showthread.php?t=1868

[vo_danh]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

When I plug the power into the monitor, with or without the vga cable, the monitor blinks white to black pulsing about every second. The lights at the bottom right that numbers from 1-4, the 1 and the power button blinks green. The picture is quite similiar to the pics above posted, there is no discoloration or bad caps as far as I can tell. I can not see anything on the screen even with a flash light. I will take pictures as soon as I can get my camera back.

[vo_danh]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

(My C637 also tested ok on my capacitance meter of 477uF).

Please advise if i should continue to test all the capacitors according to my description so i can start removing them and testing them one by one.... or if you need more info.

[jetadm123]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

(My C637 also tested ok on my capacitance meter of 477uF).

Please advise if i should continue to test all the capacitors according to my description so i can start removing them and testing them one by one.... or if you need more info.

I would hold off on removing the caps and testing them. Good photos are critical, since that is what members rely on because of the lack of schematics and the fact that it allows members to look over the entire board to recommend test points for you to take voltage/resistance measurements. Trained eyes can also see something on photos that you may have missed.

[retiredcaps]

Re: Dell 2005FPW PS PROB AND VERT ROLLING

(My C637 also tested ok on my capacitance meter of 477uF).

Caps might have correct uF, but high ESR (ohms). You need an ESR tester to measure ESR.