820-00165 Boots sometimes and then shuts down after several hours

This is a liquid damaged board that I repaired initially by cleaning up the one wire circuit and replacing the backlight driver.

Initially after 30 mins of testing thought the board was good to go but it seems that after using it for a couple of hours it just shuts off, sometimes it will restart upon a SMC reset and sometimes if I leave it for a couple days and come back to it will boot up again. At the moment the board is in a state of not booting up properly...will use 300 to 400 mA and then drop to 25mA with some fan spin.

PPBUS_G3H = 8.56V
PP3V42_G3H = 3.438V
PP5V_S5 = 5.03V
PPVRTC_G3H = 3.324V
PP5V_S4RS3 = 0V


Staff member
First of all, welcome to the forum!

You should reball SMC first.
Check for corrosion in other areas too.
Thanks for the welcome notice.

I have checked other area's for corrosion and not found any

I'm going to assume that you are suggesting SMC reball rather than SMC reflow to ensure a better connection and no issues with the pads?
(I have not performed this task previously, do you have any suggestions to avoid frying the SMC?....recommended temp and flow for quick hot air stn?)



Staff member
I can only recommend to practice on scrap boards.
Air flow/temp must be adjusted for each station; there is no universal formula.
You can try a reflow, but is not the best option; sometime works...
Since I don't have a stencil to do .3mm, I have done a reflow and I'm checking out the laptop.

Do you have advice on how to check the motherboard out? I'm currently using istat menus to show stats.

Machine has been on for 2 1/2 days so far....going to leave another day or two before I conclude it's fixed.


Staff member
Any reason to quote an entire post visible few centimeters anove?
Please, maintain forum aesthetic...

Play YouTube; I like Arabesque, BZN and olders.
You can also run a stress test, like Unigine Heaven.
Look at HWMonitor indications, if needed.
Not sure what I hit but will try to avoid the "quoted" post response, I've removed my fashionable error.

Ran Unigine Heaven to stress test and looks like it's working.

Thx for helping with this one.