Re: Dell Monitor blinking LED
My apologies, one side is 17.82V and the other is 17.83V
Dell Monitor blinking LED
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Re: Dell Monitor blinking LED
So the 12V is there. That 17.26V is unregulated and should drop down once the backlights are on.
Let's confirm you are measuring the DC voltage on the picofuse correctly.
1) Put your black probe on a ground screwn.
2) Put your red probe on one side of the picofuse? What is this reading?
3) Put your red probe on the other side of the picofuse? What is this reading?Last edited by retiredcaps; 01-10-2013, 12:20 AM.Leave a comment:
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Re: Dell Monitor blinking LED
#1
E = 0.00V
C = 17.26V
B = 0.00V
#2
B = 0.00V
C = 5.00V
E = 0.00V
#3
1 = 2.12V
2 = 0.00V
3 = 3.30V
4 = 5.00V
Last edited by Pentium4; 01-09-2013, 05:39 PM.Leave a comment:
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Re: Dell Monitor blinking LED
You show you are getting 3v and 5v,so the only thing missing is the 12v,which feeds the Inverter via the PF751.This is rectified by D701,which is a Schottky,and you should be able to measure it across C703,C704 and C712.Leave a comment:
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Re: Dell Monitor blinking LED
What is the DC voltage for each of the three ICs mounted on the heatsinks in the upper right hand corner?
Report each pin (BCE) with respect to ground.Leave a comment:
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Re: Dell Monitor blinking LED
You usually have to lift one leg of a resistor to check it properly.
The measured resistance should equate to the the colour bands.
http://www.hobby-hour.com/electronic...calculator.phpLeave a comment:
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Re: Dell Monitor blinking LED
The measured resistance should equate to the the colour bands.
http://www.hobby-hour.com/electronic...calculator.phpLeave a comment:
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Re: Dell Monitor blinking LED
I'm only getting 0.0125V on both sides of PF751Leave a comment:
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Re: Dell Monitor blinking LED
Verify that you have DC voltage on pf751 (both sides) wrt to cold ground. What is reading for both?Leave a comment:
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Re: Dell Monitor blinking LED
What are the DC voltages on the connector between the power and main board?Leave a comment:
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Re: Dell Monitor blinking LED
Okay so I replaced both of those FU9024N's and it's still having the same issue. Not even a brief flash when it powers upLeave a comment:
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Re: Dell Monitor blinking LED
InterestingI ordered 10 of those FU9024N's, hopefully it will fix the issue!
Leave a comment:
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Re: Dell Monitor blinking LED
That fu9024 is driven by the PWM IC, the output is Variable DC depends on the pulse width of the drive signal from the PWM IC, the wider the width the more DC feeding the Royer Oscillator, the brighter the lamps get, if the fu9024 has shorted Source to Drain, the Oscillator will run at full power (max DC feeding the oscillator, max LAMP brightness) as explained by RTECH.Leave a comment:
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Re: Dell Monitor blinking LED
Thank you very much for the repliesPF751 is good
Testing between pins C and E on Q743 and Q751, they are both shorted
When it first turns on I don't get a flash at allLeave a comment:
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Re: Dell Monitor blinking LED
On many occasions,when one of the Fu9024s go short,you get a situation where the screen is totally white when you apply Power WITHOUT the On button being pressed, and then it works normally when the On button is pressed.If they test good I suspect one of the CCFLs has failed.Leave a comment:
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Re: Dell Monitor blinking LED
If it does then it could be one of the transformers though they dont often fail on this
board - meter on 2000ohms check the secondary windings ( Think it is the two pins on one end there are 3 but 2 are conneted)Last edited by selldoor; 12-28-2012, 03:54 AM.Leave a comment:
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Re: Dell Monitor blinking LED
See if picofuse PF751 (right above the big filter cap) is blown after you replaced the c5707s.
See if Q743 and Q751 are shorted. These may the FU9024s I refered to as per post #18 and post #2 by UniT3d.
If the above are all good, then you will have to check the main board and make sure that BL_ON is > 3.0V DC.Leave a comment:
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