(347) 552-2258 [email protected]

820-01041 - Randomly starting

overshoot

overshoot

Member
Hi,
I have an 820-01041 that is really playing with my nerves.
It was liquid damaged on the edge where the air intakes are.
Initially I was getting 5V only. The 1.1V LDO line was not coming on.
It had a shorted capacitor on the SSD rail. Replaced it and a few others that looked nasty and got it to turn on.
I had to clean the CD3215 area as well and replaced a few tiny parts that looked off to play safe.

That was last night.
I got the laptop to turn on with the user password prompt so I turned it off, put it for charge overnight and asked customer about his password to run some tests in the morning.
Morning it wouldn't turn on.

Now I am getting it to randomly go to 20V and turn on and sometimes, it stays at 5V with 0.05A, floating, this time the 1.1V LDO is present.
When it starts, it will load the recovery mode (I guess) but it won't reach that and then fans will go full speed and laptop will shut off.
I am getting about 100ohms to ground on the 0V9 SSD rail compared to about 200 ohms on a working board.
The 1.8V and 2.5V SSD rails compares fine with my known working board.

Does that sound like a dead SSD to you?
What can cause the fans to ramp up like that with then the Mac shutting down? Sensor issue or short detected?
 
overshoot

overshoot

Member
Already have removed all the caps which are not underfilled with the NANDs but value remains the same.

More importantly, what can cause the fan to ramp up fast like that with a shutdown next from your experience? (it takes a second to do that)
I am going down the rabbit hole on the SSD/NAND but what if something cause it.
 
overshoot

overshoot

Member
it was caused by an intermittent or partial short. I did remove all the nasty caps remaining and board did boot up fine.
 
overshoot

overshoot

Member
No it was some caps on PPDCIN_G3H, PP5V_S4_X_USBC and P3V3TBTT_RAMP

However I have another issue. His touchbar display is gone but he told me about that. Touch works however.
Problem is, when screen goes to sleep, it won't wake up. If I restart the laptop, same thing, screen stays off but it has clearly turn on.
It's only if I disconnect the battery that I can get the screen back to work.

Could the touchbar acts up and play with the display (on the DFR_LID_OPEN_L line)?
 
2informaticos

2informaticos

Administrator
Staff member
Touchbar requires a correct lid open signal for proper work, not viceversa.
Just in case, test if machine wakes up correctly without touchbar connected.

Check LID_OPEN_LEFT/RIGHT and IPD_LID_OPEN signals, when the problem appears.
 
You must log in or register to reply here.
Top