Dell 3008wfp faulty power supply

[Maxidud2000]

Re: Dell 3008wfp faulty power supply

Hi Guys,
Today I got a Dell 3008wfp without a picture but the Blue power LED still lights up and therefore I dont think that it is power related problem. I read all the 11 pages of contribution about this thread and am happy that there were several who managed to repair their TV's. Unfortunately I did not come across anyone having my problem that is power ok (Blue LED on) but without any picture. Can anyone pls give me an indication what to chk or maybe D22 could still be the faulty component ?
Many thanks and keep up this excellent site.

[selldoor]

Re: Dell 3008wfp faulty power supply

First test would be connect it up to a known working source - pc with a vivid picture.

Can you see a very dark image on screen perhaps check with a flashlight at different angles.

Does the panel flash on for even a second when you first switch it on.?
Can you switch it off with the power button?

Check out the thread for instructions on how to dismantle the set - it appears to be rather difficult. Then post pictures
Welcome to the forum-
We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed
https://www.badcaps.net/forum/attach...1&d=1290283049

https://www.badcaps.net/forum/attach...7&d=1280167246

It will be useful if you can say a bit about yourself - skills tools etc.

[layte]

Re: Dell 3008wfp faulty power supply

My 3008 died a couple of months ago, but thanks to a combination of this thread and another forum it was brought back to life yesterday. So I would just like to give a huge thanks to everyone involved.

Surely with the number of monitors dying (just outside of the 3 year warranty....) with the exact same problem (the D22) Dell should be offering to repair them as they obviously used parts that were not of sufficient quality for the job.

[Maxidud2000]

Re: Dell 3008wfp faulty power supply

Hi thanks for your reply.
A brief about myself: Im a computer tech with years of experience in repairs. Component level trouble shooting with very good soldering experience even on SMD's.
The Dell 3008 has only the Blue LED that comes on when inserting the mains plug but otherwise no flicker on the screen with or without an input source. It does not seem to be a back-light problem either. At present I'm not near the monitor but if I'm not mistaken the blue power LED won't switch off when the power button is pressed.
The unit is still dismantled and it was not an easy task especially to remove the plastic front trim. I will try and upload images later. In the mean time I would like to know if another other one had suffered the same problem on this unit. ie: Blue power LED 'on' with no picture.
Thanks to ALL.....

[jetadm123]

Re: Dell 3008wfp faulty power supply

Maxidud2000- sounds like you're at least getting voltage to the logic board. with your monitor hooked up to a computer in a darkened room, try shining a bright light at an angle against the screen to see if you can see an image of the Windows desktop. If yes, then try checking the fuse and voltage (at the fuse) of the inverter board.

[Maxidud2000]

Re: Dell 3008wfp faulty power supply

jetadmin, thank you for your feedback but as explained above I dont think its an inverter problem. Fuse checked and found ok. I will try to monitor any DC voltages present and will let you know. Again I would like to ask if any other person experienced this type of fault on the Dell 3008, with a power LED on but still no pic. Help greatly appreciated. Thanks

[budm]

Re: Dell 3008wfp faulty power supply

For the backlights to work, it needs 24vdc for power from power supply and BL_ON (Backlights ON) signal from the main board, so you need to verify if you have both of them.

[Threat007]

Re: Dell 3008wfp faulty power supply

Same exact issue as Maxidud2000 here. No signal coming to monitor including from on-screen menus. Back light is fully lit and obviously on (can light up a dark room). I will be doing the power fix d22 diode anyway as it is a know issue. I am not convinced that is the whole issue in this scenario though. Ideas?

[budm]

Re: Dell 3008wfp faulty power supply

If you have backlights but no pictures, then it can be that the main baord is not sending either 5VDC or 12VDC to power the T-CON board or the T-CON may have failed due to blow surface mounted fuse or regulator, that will be the next thng to check.

[kazkasneaiskaus]

Re: Dell 3008wfp faulty power supply

The same problem as Maxidud2000. The power led is on ant background lights on but no picture, even menu. Please share how did you solve this problem.
Threat007 did you change diode? Did it help?

[selldoor]

Re: Dell 3008wfp faulty power supply

kazkasneaiskaus
Please can you update your profile with country and mains voltage

[kazkasneaiskaus]

Re: Dell 3008wfp faulty power supply

I took out D22 diode and checked it. Seems it works properly. The resistance to one direction to both diodes are about 300 ohm to another infinite.

[selldoor]

Re: Dell 3008wfp faulty power supply

Thanks for updating - Yes D22 looks ok. Have you tried t find the fuses on the Panel Board (Tcon) If you can post a picture ( may have to be 3 to get it all.

[kazkasneaiskaus]

Re: Dell 3008wfp faulty power supply

Thanks for updating - Yes D22 looks ok. Have you tried t find the fuses on the Panel Board (Tcon) If you can post a picture ( may have to be 3 to get it all.

I dont't really know where these fuses are... are they smd parts? Do you have a picture where are they located?

[selldoor]

Re: Dell 3008wfp faulty power supply

They will be smd - that is why I was asking you for a picture and I can mark them on it - Do you not have a camera.

[kazkasneaiskaus]

Re: Dell 3008wfp faulty power supply

They will be smd - that is why I was asking you for a picture and I can mark them on it - Do you not have a camera.

These fuses? I checked F1 and it seems to be bad.

[selldoor]

Re: Dell 3008wfp faulty power supply

Yes - thats the sort you are looking for. To test set meter on to Ohms
and touch the probes together - should read 0.00 ohms or very near.
Then with no power to the board touch probes to each end of the fuse and post the result. Should be the same or very close to touching the probes together.

[kazkasneaiskaus]

Re: Dell 3008wfp faulty power supply

Yes - thats the sort you are looking for. To test set meter on to Ohms
and touch the probes together - should read 0.00 ohms or very near.
Then with no power to the board touch probes to each end of the fuse and post the result. Should be the same or very close to touching the probes together.

I am an electronic engineer and I know how to check fuses how ever thank you for a help.
F1 - 183 kohm
F2 - 0,5 ohm
Obvious that F1 damaged.

[selldoor]

Re: Dell 3008wfp faulty power supply

Ok - I think the "N" signifies that is is a 2 amp fuse although all manufacturers do not use the same coding

[kazkasneaiskaus]

Re: Dell 3008wfp faulty power supply

Ok - I think the "N" signifies that is is a 2 amp fuse although all manufacturers do not use the same coding

It is 2A and 63v it's written under it.
However I noticed another big problem. The cable wich connects the main bord to video imputs board is totally broken. It looks like all wires isolation is crubled. How could it happen? Heat? Sometimes when you search for small things you do't note an obvious things.