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Re: Dell E5440 completely dead
Ok. So it seems most of the parts on the supicious rail were checkd, except PQ5 and PU701, right?Comment
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Re: Dell E5440 completely dead
Unfortunately i can't find datasheet right no for PU701, but you can at least check whether 19V reach Pin1 and of course, you can check each pin for short to GNDComment
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Re: Dell E5440 completely dead
How many amps is the board taking?Comment
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Re: Dell E5440 completely dead
5 6 7 14 15 & 32 are grounded
Pin #1 receives 19.5vComment
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Re: Dell E5440 completely dead
How many amperes? Do you have a bench power supply? If yes, set it to 19.5V and power the board from it.Comment
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Re: Dell E5440 completely dead
Check where the DC adaptor connects to the motherboard. Apply power from your power supply on the DC connector pins, just make sure which is +ve and -ve first.Comment
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Re: Dell E5440 completely dead
PU701 Pin 6 & 15 short to GND means Main Power Rail short to GND. How could that Be missed before?Last edited by Sephir0th; 10-19-2021, 07:23 AM.Comment
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Re: Dell E5440 completely dead
Do a visual check first to identify if something is physically damaged, otherwise Inject voltage on that line and see what gets hot. As always, start with 1V 1A then increase amp slowly if needed.Comment
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Re: Dell E5440 completely dead
Did visual inspection before, totally clean mb.
Gonna inject voltage and report in 2 minsComment
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Re: Dell E5440 completely dead
First, Share exact Résistance to GND there in Ohms Mode, Range 200 or Auto-Range to exclude a Short with a step down Circuit.Comment
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Re: Dell E5440 completely dead
When i set it to Ω shows 20Ω not 0.Comment
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Re: Dell E5440 completely dead
20 Ohms are probably Bad News. Now you have to Check Resistance to GND of each coil. Look for a similar value...Comment
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Re: Dell E5440 completely dead
I see same value only on PL400 (both pins) all other coils have values way beyond this.Comment
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Re: Dell E5440 completely dead
That's fine then. So Voltage injection Like mentioned before. Pay Attention especially To PU401 and PU701.Comment
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Re: Dell E5440 completely dead
I inject voltage on pin 6 (+) and GND (-), 1v 1a and drown only 0.4A, no shortcircuit indication.Comment
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Re: Dell E5440 completely dead
They both share a common line through PR400. You could try removing PR400 to see which side is 20Ohms.
I suspect it might be a faulty PU701. These are fairly easy to remove and resolder. I'd try removing it and see if the 20Ohms is still there. Or you could just inject voltage, but with 20Ohms at 1V, I doubt anything will get hot (expected 0.05A flow).Comment
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Hi, I disassemble my laptop to replace the speakers, to access them, you have to remove everything including the heat sink and fan, unscrew the motherboard, lift it up a bit to access the speaker wire.
that was not the first time I dissasemble it, i did replace the same speaker a few year ago and I repaste it last year, so I had nothing to worry about. but when I put everything back together, its completely dead.
After a bit of investigating, i found one pin of the status led ribbon cable that was unglued from the cable and bend touching another pin, I bend it back at his place... -
I have bought a not complete and defective Dell Latitude 5520 for parts (needed the networkconnector (RJ45) to repair a other board).
Have repaired the other board (Dell Latitude 5540) and I wanted to know if I could find out what is wrong with the 5520 board (SouthPeak15 TGL MB 8L 19819-1) and perhaps repair this one also.
After connecting the USB-C charger (both USB-C ports on the laptop, does not have an other option) and pressing the power button, nothing happens (no lights or fans, no capslock).
Have checked with a thermal camera, and there are a couple of things... -
My question pertains to understanding the control circuity inside a Dell PT434 type battery used in Dell E6400, E6410 and other Dell notebooks?
Does anyone have a circuit diagram for the inside of a Dell PT434 battery and/or a description of how the control lines work to control this battery?
My reason for asking is I have a battery which I cannot get to charge beyond 1% in a Dell E6410 or E6400.
The LED bar graph charge indicator on the battery shows one LED lighted when the info button is pressed.
I have tried multiple different Dell power adapters. My Dell... -
Hello!
I have a Dell Latitude E5440 on bench that is completely dead, no led, no other activity like there is no power adapter connected.
The power_jack_in has voltage 19,5V, the PL4 has 19,5 in both sides and the PQ 4 has 19,5 Voltages too except the pin 4 that has 9,37v.
Any advice?
Thank you in advance!
schematic: https://drive.google.com/file/d/0B6I...tOR2VoV3M/view -
Hi,
So I'm trying to fix the above mentioned dell laptop. It has no signs of life at all when plugged in. If I connect the AC I noticed the MOSFET PQ5 gets very hot. So I'm assuming there is a short somewhere. I'm still learning so please could someone assist me. Thanks for any help given.
I did try swopping the Mosfet which is a AO4423 with one from a donor board being a SI4483ADY as they both have the same VDS @ 30V. once I swopped the Mosfet when I plugged in the charger it would just switch off so I swopped the MOSFET back....
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