Increase voltage on Toshiba PSU pa3717e-1ac3

[MegaZAC]

There is an old, but working laptop PSU Toshiba pa3717e-1ac3. It outputs almost 20V with 6.32A. The task is to make giving out 24-26V with not less than 3.5A.

It is built on the attached PWM



To me it looks like DAP019D, but I only was able to find datasheet for DAP018D - https://pdf1.alldatasheet.com/datash...I/DAP018D.html

According to that datasheet, it does work with up to 28V. However, I am not sure how to make that happen, and still unsure with assumtption that this will apply to DAP019D.

Please, recommend the simplest course of action.

[kasfamily]

Hi, what's the chip here?

[stj]

check the voltage of the output capacitors before you do anything, if they are 25v they will fail - you need 35v and you need them to actually fit the board.

[MegaZAC]

Hi, what's the chip here?

The output capacitors are 25V/1500, but there is some space to install bigger ones, so it's not an issue.

[kasfamily]

The output voltage is regulated by changing the values of the resistors by 2 pin DAS001
For example

[MegaZAC]

R135 is 2kohm, R133 is 121.5 ohm or its not clear which one is that. Should I replace R135 with lower resistance or higher? Would only R135 be sufficient ?

[MegaZAC]

Youtube made a miracle and suggested a video where my question was well-explained https://www.youtube.com/watch?v=yxNY-iYaok0

I need a 20kohm resistor. Unfortunately, in the video the psu was unable to output more than 1A after been modified to 24V. Any ideas?

[stj]

maybe the controller has overvoltage protection or something - time to read datasheets.