hp cdl50 la-d707p rev 1.0

[mazloum]

hp cdl50 la-d707p rev 1.0
hi
this board has a problem in 3.3v which is shorted to ground, the charger led is ok, i can find 5v but all others are not present, i cannot determine the where the short is. i tried all capacitors near pjp2, but with no success.
here is the schematic:
https://www.badcaps.net/forum/showth...light=la-d707p

[Techtiger]

Re: hp cdl50 la-d707p rev 1.0

Did you remove the Jumper PJP2 to find out which side is short the GND ? If no Jumper remove one pad of PL9 and test the short side

[mazloum]

Re: hp cdl50 la-d707p rev 1.0

Did you remove the Jumper PJP2 to find out which side is short the GND ? If no Jumper remove one pad of PL9 and test the short side

i removed pl9, but still shorted on pjp2

[mazloum]

Re: hp cdl50 la-d707p rev 1.0

thi

[mcplslg123]

Re: hp cdl50 la-d707p rev 1.0

Why not open PJP2 and check as suggested by techtiger??What is the resistance on PL9-both pads while coil is removed?? 3V line does show low impedance on many newer mb's. Are you checking the impedance on PL9 just after applying power?? Else connect both ends of PL9 to ground for some time(power removed), say for a minute and then remove connection to ground and check resistance again on both pads of PL9.

[mazloum]

Re: hp cdl50 la-d707p rev 1.0

Why not open PJP2 and check as suggested by techtiger??What is the resistance on PL9-both pads while coil is removed?? 3V line does show low impedance on many newer mb's. Are you checking the impedance on PL9 just after applying power?? Else connect both ends of PL9 to ground for some time(power removed), say for a minute and then remove connection to ground and check resistance again on both pads of PL9.

I opened jumper pjp2 and checked voltage as shown in the photo. i get 3.3v on the labeled side of the jumper when i press the power button, this voltage will remain for about 10 seconds....
but the short remains in pjp9 and pjb4

[Techtiger]

Re: hp cdl50 la-d707p rev 1.0

assuming PU6 is short remove PJP9 PJP4 check if the PU6 side is short or remove PU6 i the short is gone

[mazloum]

Re: hp cdl50 la-d707p rev 1.0

i removed pu6 pjp9 pjp4 but the short is still
i removed pu2 also, but still short

[Techtiger]

Re: hp cdl50 la-d707p rev 1.0

i removed pu6 pjp9 pjp4 but the short is still
i removed pu2 also, but still short

Do you have a power LAB to apply voltage ?

[mazloum]

Re: hp cdl50 la-d707p rev 1.0

Do you have a power LAB to apply voltage ?

yes i have

[Techtiger]

Re: hp cdl50 la-d707p rev 1.0

Inject 1V increase amps pjp9 pjp4 and see what’s getting hot with this method https://youtu.be/AOALg_rDIZk

[mazloum]

Re: hp cdl50 la-d707p rev 1.0

i did, but not even any item get hot