Dell 3007wfp No Image

[S. Bouchard]

Hi!

I have a Dell 3007WFP with the following behavior.

The monitor does power up (blue led on) when NO DVI input is connected. The Backlight does come on but the Self Test (color cycling) does not show up. If I press the power button, the monitor does turn off. If I connect a DVI input (PC), the power led turns amber. The devices connected to the USB ports are all functioning.

As an added note, in the past (once every few months) when the monitor would resume from sleep, I have had the whole screen filled with vertical lines (bands) which would be resolved by turning off the power on the monitor and turning it back on.

Any help in trying to fix my monitor would be greatly appreciated.

P.S. I did post this information in the 3008 thread but figured it would be better in a separate thread.

[S. Bouchard]

Re: Dell 3007wfp No Image

Update: I did open the Monitor today to inspect all the boards.

The power supply looks fine and none of the capacitors appear to be leaking or bulged. I am presuming that this board is ok given the monitor does have power and the backlight does come on. Please let me know if my assumptions are wrong.

I looked at the controller board and the fuse F1 (2A 63v) appears to be bad. Using my digital meter and putting the probes on each side, I get something like 11.xx M Ohms.

All the cables appear to be in very good condition. They are not crumbling / disintegrating like they were in post #240ish of the 3008WFP thread.

Unless I messed up on testing this fuse, it will have to be replaced / bridged or whatever. However, something caused it to blow so I presume I would need to figure out what did it before dealing with the fuse?

I have had this monitor since they became available about 7 years ago. Other than going on standby, I never really turn it off. Although the capacitors look fine, given their age, could they be due for replacements?

I am a novice when it come to electronics. So I would appreciate if you could advise me on my next steps.

[S. Bouchard]

Re: Dell 3007wfp No Image

Anyone?

[mohomane]

Re: Dell 3007wfp No Image

hi for the age of your monitor,just change the caps,they dont have to show a bulge.

[S. Bouchard]

Re: Dell 3007wfp No Image

hi for the age of your monitor,just change the caps,they dont have to show a bulge.

Thanks for the reply.

Besides replacing those capacitors and the blown fuse, anything else I should check?

Anyone know what brand that 2A 63V fuse is or what I should replace it with?

[Gingerbeer]

Re: Dell 3007wfp No Image

Is it a 20mm fuse with solder tails?

I just removed it, and soldered in a fuse holder and clipped in a 3.15A 20mm fuse - both from Maplin. Cost me a massive 82 pence.

My monitor is the 3007WFP-HC though, so I couldn't say whether it's vastly different inside.

[S. Bouchard]

Re: Dell 3007wfp No Image

How about this fuse to replace the original on the Controller Board?

http://www.mouser.com/ProductDetail/...9N%252bAmFo%3d

[S. Bouchard]

Re: Dell 3007wfp No Image

Another question.

In taking inventory of the capacitors on the power supply board, I came across a Taicon 4.7uf 50v 125c capacitor. Most premade kits show a 47uf instead. What gives?

There is also a Ltec 1uf 50v 105c https://cdn.badcaps-static.com/pdfs/...3154c18b5e.pdf so what would be a good replacement for that... I can't seem to be able to find something matching the ripple current?

[rswails]

Re: Dell 3007wfp No Image

I also have this same fuse blown on my TCON board of my HP LP3065 LCD
F1 (2A 63v)

It is not a 20mm fuse, this is a surface mount fuse more like 4mm ish. He said the fuse was blown on the tcon board, not the power board. The tcon board doesn't have a 20mm fuse.

Anyone know any common reasons fo TCON / logic board fuse to blow?

[S. Bouchard]

Re: Dell 3007wfp No Image

Based on the replies I got those far, I presume the aging capacitors on the power board would be the source.

I am going to replace all the capacitors on that power board and then replace the fuse and hope that solves it.

[Gingerbeer]

Re: Dell 3007wfp No Image

How about this fuse to replace the original on the Controller Board?

http://www.mouser.com/ProductDetail/...9N%252bAmFo%3d

Apologies for the late reply. The fuse I was talking about was a 20mm cylindrical fuse near the mains socket on the power board.

[S. Bouchard]

Re: Dell 3007wfp No Image

Ok. I changed the Capacitors on the PSU. I also replace the surface mount fuse on the controller board.

I connected power to the monitor and it is now going into test mode (which it was not doing anymore). I'll connect it to the PC but I am assuming it is ok.

However, I do hear some slight humming / buzzing coming from the power board... What might be causing this?

[budm]

Re: Dell 3007wfp No Image

Does the buzzing sound change with the brightness level setting?

[S. Bouchard]

Re: Dell 3007wfp No Image

Quick update: The faint whistling sound is coming from either the 330uf 50v or the 470uf 35v ( i think or some part next to them). When I connect power to the board, I can hear the capacitor charging (sound wise)... the sound is slightly louder when it is charging and then it gets quieter but still makes a faint high pitch sound.

So is it one of the capacitor or something else causing it?

[S. Bouchard]

Re: Dell 3007wfp No Image

High Pitch sound could also be coming from the disc capacitor

102M
KX250
X1Y1

Would one of those potentially also emit a high pitch sound? The sound is faint and I am not certain how much I would be able to ear it inside the casing and all but with the Power Board out, I can hear it.

[S. Bouchard]

Re: Dell 3007wfp No Image

Does the buzzing sound change with the brightness level setting?

Sorry I missed your post for some reason.

Right now the monitor is disassembled. It is doing this faint high pitch sound with only the power board connected and powered.

[S. Bouchard]

Re: Dell 3007wfp No Image

The monitor works now but I just need some feedback on this faint high-pitch noise.

Is it normal or not?

Is it that capacitor or maybe something else. What should I look at to isolate / fix this (if it is something of concern)?

[S. Bouchard]

Re: Dell 3007wfp No Image

Here is a picture of the part of the power supply board where I believe the high pitch noise is coming from.

Could this 102M KX250 X1Y1 capacitor be responsible for it? Should I replace it or could some other part near it be responsible? All other capacitors have been replaced and even re-swapped with no change on this high pitch.

I just need this last bit of feedback to wrap this up. Like I said the monitor now appears to be working but I don't want to put it back together if this faint high pitch noise is likely to result in some other damage in the near future.

[budm]

Re: Dell 3007wfp No Image

If you push it with wooden stick, does it change its pitch? It may be running at the wrong frequency also, hard to tell.

[S. Bouchard]

Re: Dell 3007wfp No Image

If you push it with wooden stick, does it change its pitch? It may be running at the wrong frequency also, hard to tell.

When I press (with a wooden stick) on this 75 Kohms resistor, the pitch does change. It doesn't completely stop it from making that faint high pitch sound but the frequency of the sound changes / become significantly dampened (like absorbed by the wood).