HP Pavilion x360 11-K - 3.3V IC hot

Hello everybody.

I am stuck with this motherboard HP Pavilion x360 11-K (Wistron HEVIN-BSW 14269-1 448.05U04.0011).

The 3.3V or 5V IC get very hot to touch. When just plugged in. Power supply pull 0.21a.

I have 19.5V at current resistor. but no 3.3v / 5v.

No schematics available. I am stuck. help will be appreciated.

Thank you.

Check resistance to ground on LDO output.
If resistance is low - short-test: szkolenie-nr-1-podstawy-diagnostyki-plyt-glownych-laptopow-t986.html#p5699.

Thank you for your reply sir.

Do you know the pin number for the LDO? i dont have schematics and i dont
know what IC chip the 3.3v / 5v are. Does anyone know what package?

Here is a picture of the effected area. It gets very hot, but no signs of
any current on power supply.


Thank you for your help.

What is the signature of the integrated, from the photo you do not read?

thanks, they say

MS56B

Ar5MC

thank you

Please provide a clear, high resolution photo of this IC (to show all its markings).

it hard to see markings on IC.

MS56B

Ar5MC





Plate is Wistron HEVIN-BSW 14269-1 448.05U04.0011

thank you sir

Marking code MSxxx - SY8208B. See: lenovo-b70-80-prosba-o-identyfikacje-elementu-t51265.html - "5V LDO output is on pin 7"

Ar5MC - probably compatible with SY8208C (marking code MTxxx)

Check resistance to ground on marked pins:

thank you for your help.

Top IC (Ar5MC)
-------
Pin 7 = 5V
Resistance to ground on marked pins from picture = .860mΩ

Bottom IC (MSxxx)
-------
Pin 7 = 2.9V
Resistance to ground on marked pins from picture = 93Ω

CharlieZee napisał(a):Resistance to ground on marked pins from picture = .860mΩ

Short-test on this pin.

do i perform short-test on pin 7 of IC or the capacitor that you show in picture?

Yes. On the capacitor pin is easier - is bigger.

ok thank you.

i inject 2V into the top capacitor and powersupply pull 0a

i inject 2V into bottom capacitor and powersupply pull 0.45a but nothing is getting hot.

Impossible. I=U/R, I= 2V/0,86Ω=2,32A. Check resistance ones again.

Read about short-probe - english version is below polish version.


Connect GND motherboard and GND power suply.
Connect + power suply like on the picture:


The maximum voltage is 3.3V, but start at 1V.

thank you for your time sir.

i check again like you say, but i get the same results. i make clear picture, of what i check.

Measure the resistance to ground on coil PL4501.

Measure the resistance to ground on highlighted capacitor near PU4501.

resistance to ground on coil PL4501 = 7.80 kΩ

resistance to ground for highlighted capacitor near PU4501 = 32.8 kΩ

thank you for your time.

Measure the resistance to ground on pin 2 of PU4501 again just to be sure.

what resistance should you expect from normal/working IC pins?

CharlieZee napisał(a):what resistance should you expect from normal/working IC pins?

I wold expect the resistance to ground on pin 2 of PU4501 in kΩ range.

Remove the PU4501 from the board, after that measure the resistance to ground on pad 2 od PU4501 place again.