Dell 2007FPb - No power at all

[slawson2000]

Re: Dell 2007FPb - No power at all

Not sure if I did this right, but was checking voltage two ways, between the two leads of the capacitors and also by one lead of the capacitor to the ground.

C44 and C60 - no voltage.
Could not find a C58, but C50 - no voltage.
U2, U5, U13 - no voltage.
J4/J9 pin 8 had no voltage.

However, the 19v from power supply is making it across to the logic (?) board and then across pin 11/12 to the USB/power supply board and then across the 3A fuse.

[slawson2000]

Re: Dell 2007FPb - No power at all

Next step?

[slawson2000]

Re: Dell 2007FPb - No power at all

Anyone? Is this a lost cause?

[budm]

Re: Dell 2007FPb - No power at all

Sorry, I have been busy. I will see if I can find the the USB/sub-power supply board (I have the main power supply and the Inverter board) so I can give you the test points, most of the time the two diode that are connected in parallel failed.

[slawson2000]

Re: Dell 2007FPb - No power at all

Thanks, post it up when you can...

[budm]

Re: Dell 2007FPb - No power at all

No luck finding the board at the recycle place, but did you check these diodes as shown in the diagram? FD3~FD8.
https://www.badcaps.net/forum/showth...highlight=2007

https://www.badcaps.net/forum/showth...highlight=2007

[slawson2000]

Re: Dell 2007FPb - No power at all

I have not, what exactly am I testing? I see the diagrams, but not sure what side or how to test.

[budm]

Re: Dell 2007FPb - No power at all

You will test for short /or low Ohm resistance reading in both direction on its 2 legs which will indicate bad diode. you can set to 200 Ohm scale on the meter.
You can see what the diode looks like in the pictures of that link.

[slawson2000]

Re: Dell 2007FPb - No power at all

FD3 to FD8 all read around 90 Ohms with leads in one direction, open with the leads switched.

[slawson2000]

Re: Dell 2007FPb - No power at all

Next step?

[slawson2000]

Re: Dell 2007FPb - No power at all

Should I get a replacement board? Anything left to test?

[budm]

Re: Dell 2007FPb - No power at all

I do not have any more idea, I cannot find the spare board.

[slawson2000]

Re: Dell 2007FPb - No power at all

Could this be it? See the brown area toward the top.

[budm]

Re: Dell 2007FPb - No power at all

That looks like stain, can you clean it off with alcohol?

[slawson2000]

Re: Dell 2007FPb - No power at all

Well, apparently I can. I thought it may have been a burn or something indicative of a bad board.

Anyone else have any ideas?

[slawson2000]

Re: Dell 2007FPb - No power at all

Anyone have any more ideas? Or is this thing headed to parts (if I can confirm which ones are good) or just junk it. Anyone?

[slawson2000]

Re: Dell 2007FPb - No power at all

I know someone smarter than me can point me in the right direction... Please?

[Lumberjack777]

Re: Dell 2007FPb - No power at all

I'm a little lost as to where you are at in this whole process. If you have a good lcd panel and want to salvage the monitor you could buy one from ebay with a broken screen. Then mix and match the power board or main board and even use it for voltage tests, and to learn from. Here's one that costs less than even buying a power board for your monitor. And you get everything inside. http://www.ebay.com/itm/Dell-UltraSh...b#ht_464wt_962

[slawson2000]

Re: Dell 2007FPb - No power at all

In all honesty I am not sure where I am in the process either (e.g. newbie). I tested some voltages as posted. I am not sure the LCD screen is good because I can not get any power to register on the switch or screen. Any help is appreciated.

[slawson2000]

Re: Dell 2007FPb - No power at all

Anyone? Should I start over - anything else to check?