Defective Hall sensor? - Page 1
Forum section: electronics / general

author: rexxar
author_rank: Frequent Contributor
timestamp: December 06, 2013, 08:35:42 pm
content: My laptop seems to have developed a fault (again). It has a magnetic sensor to detect when the lid is closed, which seems to have died and is intermittently telling the system that the lid is closed. I'm assuming it's a Hall effect sensor. It's in a SMD transistor package (which I can't remember the name of), and it's marked 248jl. My question is, do these sensors often go intermittent like this, and where can I find a replacement?

author: TheEPROM9
author_rank: Frequent Contributor
timestamp: December 06, 2013, 08:52:08 pm
content: If you can't find a replacement then it might be worth removing it and jumping it to always keep the display on. I assume that because you know which device it is, you have found a datasheet or other type of reference material.

author: rexxar
author_rank: Frequent Contributor
timestamp: December 06, 2013, 09:42:05 pm
content: I can't find anything for that part number, though.Removing the sensor has fixed the problem, but I'd still like to find a replacement. Any ideas?

author: amyk
author_rank: Super Contributor
timestamp: December 07, 2013, 12:30:00 pm
content: Laptop model? It's schematic time...

author: SeanB
author_rank: Super Contributor
timestamp: December 07, 2013, 01:49:19 pm
content: Small reed switch not a good substitute with an uprated magnet ( old CDROM optical block magnet) to drive it.

author: rexxar
author_rank: Frequent Contributor
timestamp: December 08, 2013, 07:05:34 am
content: Quote from: amyk on December 07, 2013, 12:30:00 pmIt's a Toshiba Satellite L505d-ES5025.I don't know much about hall sensors. Would any part off Mouser work as long as pinout and supply voltage is right, or is there some other characteristic to look for?

author: Psi
author_rank: Super Contributor
timestamp: December 08, 2013, 09:29:52 am
content: It depends what exactly the chip does. It could be a raw hall sensor or a module with amp or other logic.

author: amyk
author_rank: Super Contributor
timestamp: December 08, 2013, 10:24:37 am
content: Quote from: rexxar on December 08, 2013, 07:05:34 amDatasheet:http://www.mst-mj.com/uploads/soft/110104/1_2252022661.pdfYou're welcome.

author: rexxar
author_rank: Frequent Contributor
timestamp: December 08, 2013, 03:20:56 pm
content: Did you really find a schematic for my laptop? Where'd you come up with that?

author: amyk
author_rank: Super Contributor
timestamp: December 09, 2013, 06:50:17 am
content: No but I found theL500which turned out to be close enough.

author: djococaud
author_rank: Regular Contributor
timestamp: December 13, 2013, 03:06:41 pm
content: Does anyone know why there is a varistor here (D46) ? Since it's not connected to the outside, what does this varistor protects ?

author: SeanB
author_rank: Super Contributor
timestamp: December 13, 2013, 06:40:21 pm
content: This sensor is at the end of a cable exposed to the edge of the laptop where there is a strong chance that a charged up body will touch it at this point with enough stored charge to jump the small air gap to the internals of the unit. The VDR is there to protect the inside of the laptop, like the south bridge it is connected to directly, from ESD damage from these events.

author: Sublime89
author_rank: Newbie
timestamp: January 29, 2016, 01:12:30 am
content: I have the same problem with a hall sensor keeping my gateway laptop screen from turning on. I'm wondering how I would remove the this sensor like op said he did and jump it to keep the screen always on?? Here is my thread if someone can help.https://www.eevblog.com/forum/repair/faulty-hall-lid-sensor-laptop/

author: dexters_lab
author_rank: Unknown
timestamp: January 29, 2016, 07:22:42 pm
content: in windows there is an option to disable the lid sensor in the power options