Re: Dell 2407wfp - No power
So, I was lowering the main metal chassis cover over the circuit boards, and I shorted something near the 120VAC plug and popped my house circuit breaker. There was a spark and the electricity in all the bedrooms cut off immediately.
I no longer have 19V at F701, but I do have continuity through it.
I lost continuity through F601 (the big fuse beside the 120V socket) though. It says T4AH/250V. What does that mean? Can I just find another fuse and replace it? Also, why would you design a fuse holder that you have to desolder to...
GuySmily
Member
Last Activity: 06-12-2018, 01:27 AM
Joined: 12-22-2013
Location: Sacramento, CA
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Last edited by GuySmily; 12-23-2013, 10:06 PM. -
Re: Dell 2407wfp - No power
Not at home right now, but I did snap a couple pics last night.
First two images at this link:
[url]https://picasaweb.google.com/101917176603297073384/Dell2407WFP?authuser=0&authkey=Gv1sRgCN-krNuDqb-6gwE&feat=directlink[/url]Re: Dell 2407wfp - No power<br /> <...rectlink[/url]Leave a comment:
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Re: Dell 2407wfp - No power
Okay, I must have screwed something up earlier. I KNOW I had 0.00V readings (as opposed to the usual -20mV or whatever when there's no connection), but all of a sudden I have readings on all the voltage regulators, and they appear to be correct.
Scroll down to pics with multimeter:
[url]https://picasaweb.google.com/101917176603297073384/Dell2407WFP?authuser=0&authkey=Gv1sRgCN-krNuDqb-6gwE&feat=directlink[/url]
[b]Main board voltage regulators:[/b]
[b]Q6[/b] - near connector to power board CN701)
Line 1: J598...Last edited by GuySmily; 12-23-2013, 03:10 AM.Leave a comment:
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Re: Dell 2407wfp - No power
Are there any diodes that I can't test on the board by simply checking for continuity in both directions?
For example, with my multimeter in diode mode, I see voltage in both directions in the diode below your probe here:
[url]http://s807.photobucket.com/user/budm/media/DELL/Dell%202407WFPB/DSC00605.jpg.html?sort=3&o=5[/url]
I don't know how diode mode works, but on that diode I see 0.530 volts in one direction and 0.155V in the other.
If I short the two test probes together, I get 0V.
On the...Last edited by GuySmily; 12-23-2013, 01:37 AM.Leave a comment:
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Re: Dell 2407wfp - No power
lol the first thing that came up when I googled "2407wfp diodes" was this thread. Nice job, Google.
I remember seeing a thread a month or two ago where someone checked a million diodes, but I haven't found it since. Will keep looking.
Thanks for all your help!Leave a comment:
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Re: Dell 2407wfp - No power
These two connectors match your standby readings:
CN702:
1 = 0V
2 = NC
3 = 1.691V
4 = 18.9V
5 = 18.9V
6 = 18.9V
7 = 0V
8 = 0V
CN701:
1 = 0V
2 = NC
3 = 1.691V
4 = 18.9V
5 = 0V
6 = 0V
7 = 18.9V
8 = 0V
9 = 0V
10 = 0V
11 = 0V
edit - Obviously I can't turn the monitor on, so I can't compare "On" voltages.
I have 0V on these 3.3V VREG:
[url]http://s807.photobucket.com/user/budm/media/DELL/Dell%202407WFPB/DSC00073.jpg.html?sort=3&o=58[/url]...Last edited by GuySmily; 12-23-2013, 12:36 AM.Leave a comment:
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Re: Dell 2407wfp - No power
Cool.
So far, 0V on everything pictured except for 3.23V on FD7 (see edit2, above) and 19V on the inverter fuse F1.
STBY = standby?
Checking your CN702 readings next.Leave a comment:
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Re: Dell 2407wfp - No power
Cool, I'll start checking em out. In all the shots with only one probe shown, the black probe is on the chassis, right?
edit- nm, I guess that's pretty obvious. Just being careful.
0V on everything so far..
edit2-
Ok, 3.23V on this one: [url]http://s807.photobucket.com/user/budm/media/DELL/Dell%202407WFPB/DSC00605.jpg.html?sort=3&o=5[/url]
edit3-
0V going to the T-Con. I won't even open it up unless you think I need to.Re: Dell 2407wfp - No power<br /> <...start checkingLast edited by GuySmily; 12-23-2013, 12:14 AM.Leave a comment:
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Re: Dell 2407wfp - No power
Yes, 18.9V between chassis and F701 (both legs).
edit - Looked through your pics and read the pdf. Thanks for that.Last edited by GuySmily; 12-23-2013, 12:02 AM.Leave a comment:
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Re: Dell 2407wfp - No power
I see two fuses. I set the multimeter to beep mode (beeps when I touch the prongs together) - that's good enough, right?
The big fuse by the AC input, F601, gives me a beep.
The little yellow fuse by the 5 caps, F701, also looks good.
No fuses on the bottom side I don't think. Just a few SMD caps/resistors/diodes/etc.
What's the procedure for testing that cap? Do I want to check it while the monitor is plugged in? Currently, I get no voltage reading across the cap (OL). I've never done high voltage stuff before,...Last edited by GuySmily; 12-22-2013, 11:35 PM.Leave a comment:
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Dell 2407wfp - No power
Hi all,
I have a completely dead 2407WFP here. One day it worked, the next day it didn't.
The monitor won't turn on at all, and the power button doesn't light up.
I pulled the power board to take a look at it, but honestly I don't know what to check for. None of the caps are bulging. No components appear to be burned/leaking/etc.
The solder joints on HS1 look toasty, but Q651, which is attached to it, seems to be just fine:
It also looks like something boiled/burned under C714, but I think it's just leftover... -
Re: New Members - please post your introductions here
Hi all,
I signed up to get some help with my Dell 2407WFP monitor. I'm a Computer Engineering undergrad student and I have some basic skills (I can solder and install my own car stereo, for example) but, I haven't taken my first circuits class yet so I'll need some help at the component level. Will probably start a thread shortly.Leave a comment:
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