Re: Dell E6440 laptop - Powers on, no display. Keyboard lights up. Fan spins.
Thank you all for the help. I flashed both BIOS chips using a EZP2019 and images from post #49 of [url]https://www.badcaps.net/forum/showthread.php?t=50984&highlight=e6440&page=3[/url]
Now the laptop is alive again! Thanks againRe: Dell E6440 laptop - Powers on, n...0&page=3[/url]
elfelvin
Member
Last Activity: 07-26-2023, 01:00 AM
Joined: 06-02-2021
Location: London
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Re: Dell E6440 laptop - Powers on, no display. Keyboard lights up. Fan spins.
Here are some voltage readings while getting power to the rails but no display. (Still not sure why it doesn't power on initially, will let the motherboard cool down and try again tomorrow).
PJP101/103 = 5.04v
PJP100/102 = 3.32v
PJP200 = 13.5v
PJP201 = 1.34v
PJP202 = 0.67v
PJP203 = 1.34v
PJP204 = 1.34v
PJP300 = 13.5v
PJP301 = 1.07v
PJP400 = 3.3v
PJP401 = 1.5v
PL 502/503 (+VCC_CORE) = 1.75v
...Leave a comment:
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Re: Dell E6440 laptop - Powers on, no display. Keyboard lights up. Fan spins.
Quick update!
After toying around a bit and measuring various components, the board now powers up as it did a few days ago. Part of me thinks maybe this is heat related, as I have had the board "on" for about 30 min now? I will let the board cool down and then try power it on again.
Sadly though, even in this state I still do not get any output on HDMI (external monitor). I have checked U19 and it seems to be getting power via +3.3V_RUN and +1.5V_RUN_HDMI.
+VDISPLAY_VCC...Last edited by elfelvin; 07-24-2023, 01:57 PM.Leave a comment:
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Re: Dell E6440 laptop - Powers on, no display. Keyboard lights up. Fan spins.
I've measured the following:
U146
pin 3 = 3.3v
pin 5 = 0v
pin 8/9 = 0v
pin 13/14 = 3.3v
Interestingly, a shortly while after my original post the board did power on (_all_ rails had power), however I never got any display on the LCD or the HDMI.
Today when coming back to this issue and measured U146, the board is back to how it was a few days ago, no triggering power on the IC's.
Bit of a strange one. How do you suggest I continue...Leave a comment:
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Re: Dell E6440 laptop - Powers on, no display. Keyboard lights up. Fan spins.
Thanks, this morning I actually ordered a EZP2019 programmer as I see it supported the BIOS chips on this board (Winbond 25Q64F & Winbond 25Q32F).
I am planning on removing these chips from the board, dumping what is on them as a backup and then writing a copy of the BIOS detailed in this post ([url]https://www.badcaps.net/forum/showthread.php?t=50984&highlight=e6440&page=2[/url]).
Does this sound like the right idea?
I'll look into the "ME cleaning"...Leave a comment:
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Dell E6440 laptop - Powers on, no display. Keyboard lights up. Fan spins.
As per the description, there is some life but it seems like the important power rails are not getting any juice. How can I test that the power management chip (UH1) is not at fault? My tests show that I get power to the various power chips but then the enable triggers are not there to switch them on? Are there any other tests I should be doing to pinpoint the issue?
Board: VAL91 LA-9932P Rev 1.0 (A00) 2013-09-11
PJP101/103 = 5.04v
PJP100/102 = 3.32v
PJP200 = 13.5v
PJP201 = 0v
PJP202 = 0v
PJP203 = 0v
PJP204 = 0v... -
Re: Dell Latitude 5480 - No 3v & 5v
I replaced PR102 with a 499K and now both 3v and 5v rails are working. The laptop powers on and peace has been restored in the world.
Thank you to all that commented, hopefully the diag helps someone in the future!Leave a comment:
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Re: Dell Latitude 5480 - No 3v & 5v
I believe the issue is with PR102.
When i measure continuity between pin 2 on PR102 and PWR_SRC, I get nothing. There seems to be a dry joint between pin2 and the board. I will confirm the outcome once this has been fixed.Leave a comment:
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Re: Dell Latitude 5480 - No 3v & 5v
PU100
Pin 12 - 2.7v (which should be the logic coming from MEC1501)? Not quite 3.3v though!Leave a comment:
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Re: Dell Latitude 5480 - No 3v & 5v
PR901 - 19.8v
Below are the pins i managed to find voltages on. Which 3 pins should have 3.3v?
PU901
Pin 1 - 12.6v (CSON)
Pin 2 - 12.6v (CSOP)
Pin 4 - 5.2v (BOOT2)
Pin 7 - 5.1v (LGATE2)
Pin 8 - 5.2v (VDDP)
Pin 9 - 5.1v (LGATE1)
Pin 12 - 5.2v (BOOT1)
Pin 13 - 9.1v (ASGATE)
Pin 14 - 19.8v (CSIN)
Pin 15 - 19.8v (CSIP)
Pin 16 - 19.8v (ADP)
Pin 17 - 19.7v (DCIN)
Pin 18 - 5.2v (VDD)
Pin 19 - 3.6v (ACIN)
Pin 24 - 3.1v (ACOK)
Pin...Leave a comment:
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Re: Dell Latitude 5480 - No 3v & 5v
I dont have any physical resistors in these locations, all I have are tracks.
I have highlighted the "test points" which are grounded.
This surely means that PU901 is at fault, as there is no PR960 / PR919?...Last edited by elfelvin; 06-22-2021, 08:15 AM.Leave a comment:
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Re: Dell Latitude 5480 - No 3v & 5v
Looking at all the pins on PU901 (ISL88738), I can see that PIN 20 (OTGEN/CMIN) is shorted to ground. PIN 18 is NOT shorted. Which makes me think (being a novice) would it not be best / less intrusive to first take off PR960, as it is either this resistor or PU901 which is shorted?
Trouble is that I have no idea where PR960 is on the board... anyone with a boardview who can help?
Alternatively, i am sure others may just say go straight for the charger IC and replace PU901?...Leave a comment:
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Re: Dell Latitude 5480 - No 3v & 5v
Okay, what was throwing me off was another post ([url]https://www.badcaps.net/forum/showthread.php?p=978407[/url]) which mentioned that 13v should be okay on the +PWR_SRC - I may have misinterpreted this. Let me check back at PU901 (ISL88738) to see if I can spot something there.Re: Dell Latitude 5480 - No 3v & 5v<...d this. Let meLeave a comment:
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Dell Latitude 5480 - No 3v & 5v
I have a Dell Latitude 5480 which has power going in (charger stays lit) but no indication of life from the switch or the switch LED.
On inspection I can see that I am getting 12.5v to the power 3v and 5v IC's, PU100 and PU102, however I am seeing nothing coming out. I believe these IC's are where the 3v and 5v rails are meant to start?
Is there another pin on these IC's which should be toggled to trigger these IC's to start feeding power? Any help / pointers will be appreciated.
PQ9
Pin 4 - 9v
Pin 5 - 20v
PQ4
Pin 1,2,3 -...Last edited by SMDFlea; 10-27-2023, 05:50 AM. -
Re: New Members - please post your introductions here
Hi,
I have just joined the community as a novice who enjoys an electronics puzzle
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