Panrix Microelectronix
Member
Hey Everyone,
Happy New Year!
We've got a A2337 which has a backlight fault. No physical damage or liquid damage. Customer said after removing a charger the screen went dark.
We've assessed the board and the backlight circuit shows no short. Screen has been tested with known good board and is working fine.
QP800 voltages below:
PIN 4: 12V
PIN 3: 12V
PIN: 6/5/2/1: As soon as the board is connected to power these show 12V but within 30 seconds the voltage drops and eventually ends up at 0v
Checked the components for LCDBKLT_EN_L and BKLT_SD and these all test fine (compared against known good) but SD isn't pulling the line to 0v.
QP800 has then been replaced but no change.
Despite the other input and output values of UP800 being ok, this has been replaced to rule out a bad backlight driver. Still no change.
Checked the resistors, fb lines are all ok.
Would really appreciate some direction of where else to check as I've cross compared the full circuit and I'm a bit stumped.
Thank you!
Happy New Year!
We've got a A2337 which has a backlight fault. No physical damage or liquid damage. Customer said after removing a charger the screen went dark.
We've assessed the board and the backlight circuit shows no short. Screen has been tested with known good board and is working fine.
QP800 voltages below:
PIN 4: 12V
PIN 3: 12V
PIN: 6/5/2/1: As soon as the board is connected to power these show 12V but within 30 seconds the voltage drops and eventually ends up at 0v
Checked the components for LCDBKLT_EN_L and BKLT_SD and these all test fine (compared against known good) but SD isn't pulling the line to 0v.
QP800 has then been replaced but no change.
Despite the other input and output values of UP800 being ok, this has been replaced to rule out a bad backlight driver. Still no change.
Checked the resistors, fb lines are all ok.
Would really appreciate some direction of where else to check as I've cross compared the full circuit and I'm a bit stumped.
Thank you!
