question about TPS51980B at 820-01987

[rookieme]

Hello, the macbook has power issue - stuck at 5V.
As I cannot find datasheet for TPS51980 [U7650] can someone help figuring out if there is an issue there.
Voltages of TPS51980:
pin23 VIN 12.27V
pin22 VREG3 3.31V
pin29 VREG5 0V
pin13 VREF2 0V
pin12 EN 0V

so in order to get VREG5 & VREF2 it needs the enable at pin12 and VREG3 is always on?

[mon2]

Re: question about TPS51980B at 820-01987

Remove all power. Measure the resistance to ground of vreg5 pin.

Post the measurement.

[rookieme]

Re: question about TPS51980B at 820-01987

I have already checked for shorts.
It is 17KOhm

[dellxps15]

Re: question about TPS51980B at 820-01987

820-01987 is 2020 macbook right ? 12,3 volt on vin is not good.... it should be around 13 volt.

dc in is 5 or 20 volt ?

[rookieme]

Re: question about TPS51980B at 820-01987

2020 correct
input is stuck at 5V so I'm searching for the reason

[dellxps15]

Re: question about TPS51980B at 820-01987

5v on charger is totally different problem, not related to tps51980.

check 3.3 g3hot volt if present, and all ldo volts.

[rookieme]

Re: question about TPS51980B at 820-01987

you are right
short at PP3V3_G3H
I found shorted cap at PP3V3_G3H_SSD0 and more short under shield at T2 area
is seems game over to me

thank you for your time

[dellxps15]

Re: question about TPS51980B at 820-01987

inspect ssd power ic if looks ok or bad... probably ssd got fried and unless u swap ssd nand ur board is dead, but before all that check everything

[rookieme]

Re: question about TPS51980B at 820-01987

The security chip T2 has issue so there is a no fix.
I'm wondering how 2 separate locations have short at the same line, I'm guessing over-voltage.

[moderator]

Re: question about TPS51980B at 820-01987

can someone please tell me that can i use tps51980A or tps51980 insted of tps51980B??

[Deluccia]

Re: question about TPS51980B at 820-01987

Any verdict on this?

[mon2]

Re: question about TPS51980B at 820-01987

https://www.badcaps.net/forum/showthread.php?p=1208119