Re: Dell inspiron 15 gaming laptop NO BACKLIGHT!
There is a schematic and boardview file available on this forum and I'm assuming you're using that. +LED_BL is a reference to the pins on the connector that pass 19.5V to the LCD panel to be boosted and then drive the backlight. While the machine is on and you see a faint image on the screen measure the value of +LED_BL which should be 19.5V. If you have 19.5V at the connector and still no BL the panel or cable is probably defective. If you have nothing at all at +LED_BL then there is probably an issue with enable at component Q10...
Boardsurfer
Member
Last Activity: Today, 01:23 PM
Joined: 06-07-2021
Location: Austin
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Re: Compal LA-J521P Schematic
Both of these schematics are missing pages. For example PU700 charging circuit is missing from the schematic among other things. Anyone have the complete schematic?
Correction: PU700 is actually PUB1 on the schematic.Last edited by Boardsurfer; 09-08-2023, 12:48 PM.Leave a comment:
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Re: Dell Latitude 5285 no backlight
yup that works!Leave a comment:
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Re: Dell Latitude 5285 no backlight
Okay great I had a feeling that was the issue. I'm not sure of any alternate parts but I'm pretty sure I have one of these on a donor board at my work and if you'd like I can mail it to you. Won't be back in the office till Monday however.Leave a comment:
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Re: Dell Latitude 5285 no backlight
LED_AN should be measured at PC403 , PC404 , PC405 , PC418 , PC406 or pin 1 of PD400. You could be getting an ambiguous reading at pin22 of PU400 due to issue with chip and the fact that there's a 1M resistor in-between LED_AN and pin22. We know enable is working because you have 8.8 on both source and drain on Q33. Make sure screen is open while taking readings because Hal or angle sensor could de-trigger enable signal. If you have 8.8 at LED_AN at pin 1 of PD400 then it's highly probable PU400 needs to be replaced.Leave a comment:
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Re: Dell Latitude 5285 no backlight
Please tell me the Voltage at +LED_AN again. I noticed you said +LED_AN was .380V in the second post but then later you said PD400 was 8.8 both sides?? They should be the same reading so not sure what happened there. If you have nothing at all at PD400 then it's probably an issue with enable which is page 22 component Q33 (EN_INVPWR). If you have 8.8V at PD400 it's likely to be the driver IC assuming PWM is present.Leave a comment:
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Re: Dell Latitude 5285 no backlight
Hello. This model is one of the few Dell boards that does backlight boost circuit on the main board as opposed to another PCB normally attached to LCD itself. Look at PU400 which is backlight driver IC. this video demonstrates a good method for troubleshooting this circuit despite that it's for a macbook. Hope this helps.
[url]https://www.youtube.com/watch?v=bJOXv_nAGgc[/url]Re: Dell Latitude 5285 no backlight<...ard as opposedLeave a comment:
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Need Alienware M17/M15 schematic
Alienware m15 and M17 board: ORION_AW_MB_12L
Dell Part#: WCNK6
If you have a boardview that would help as well! -
Re: Need Inspiron 5482 2-in-1 Schematic and Boardview
Thank you! FYI google drive link on that post is no longer valid but schematic should be enough....Leave a comment:
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Need Inspiron 5482 2-in-1 Schematic and Boardview
Looking for schematic and .brd thanks. Bucky/BenSolo WHL/CNL MB TVMHG 17859-1 (Board P/N CF3X3). Any schematic for the 5482 will do, don't care if it's the version with discrete GPU. -
Re: Dell Inspiron 5579/5379 board view & schematic needed
This is NOT the schematic that OP requested. This is the Inspiron 7559 schematic but you labeled the file as 5779...Leave a comment:
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