Lenovo b50-45 dc connector help

[Stevie2001]

Am trying to connect red and black from dc power supply but the lenovo dc jack has
Black
Red
Blue
Might have white also
Should i ignore the blue

[SMDFlea]

Re: Lenovo b50-45 dc connector help

Check the schematic and see the . Compal LA-B291P

[Stevie2001]

Re: Lenovo b50-45 dc connector help

pin-1 red
pin-5 black
not sure can you help

[mcplslg123]

Re: Lenovo b50-45 dc connector help

you can safely ignore any pins other then RED & BLACK. Red is for 19v and black is for ground. Rest of the pins are adp/ps id pins which are not necessary for dc supply. Those pins are important while charging battery.

[Stevie2001]

Re: Lenovo b50-45 dc connector help

you can safely ignore any pins other then RED & BLACK. Red is for 19v and black is for ground. Rest of the pins are adp/ps id pins which are not necessary for dc supply. Those pins are important while charging battery.

this is what i discovered this is causing the short.
wonder what part this is a cap or resister.
and the scratched surface.

[R_J]

Re: Lenovo b50-45 dc connector help

What is blown is similar to (PU401) RF4PG likely PU402 is a RG4QJ
Could be an SY8208CQNC_QFN10_3X3 but I am not 100% sure

[Stevie2001]

Re: Lenovo b50-45 dc connector help

2r2 resister??

[R_J]

Re: Lenovo b50-45 dc connector help

The whole ic is missing!

[Stevie2001]

Re: Lenovo b50-45 dc connector help

The whole ic is missing!

ok this is the bad ic

were can i get one of those,ebay will be best if you can help me thanks.
with the help of thermal i tracked the bad part fast,life saver

[R_J]

Re: Lenovo b50-45 dc connector help

I do not know, I don't usually repair laptop boards, likely ebay/China. Maybe someone that does laptop repairs can be more help
I see that same ic location with what lookslike the same ic but with a different marking code

[Stevie2001]

Re: Lenovo b50-45 dc connector help

I do not know, I don't usually repair laptop boards, likely ebay/China. Maybe someone that does laptop repairs can be more help

i think it maybe this
SY8208BQNC_QFN10_3X3
http://www.datasheetcafe.com/sy8208b...sheet-silergy/

[SMDFlea]

Re: Lenovo b50-45 dc connector help

PU402 is a silergy SY8208CQNC . PU401 is a silergy SY8208BQNC

I`ll upload the schematic soon.

[R_J]

Re: Lenovo b50-45 dc connector help

I believe there is a difference between the SY8208CQNC_QFN10_3X3 and the SY8208BQNC_QFN10_3X3
See if this helps (page 46)
I also saw this:
SY8206BQNC / Sy8208bqnc - 3.3V
Sy8208cqnc - 5V
Sy8208dqnc - 0.95V

So you need to replace it with the correct IC

[SMDFlea]

Re: Lenovo b50-45 dc connector help

I believe there is a difference between the SY8208CQNC_QFN10_3X3 and the SY8208BQNC_QFN10_3X3
See if this helps (page 46)

Yes, there is a difference, the SY8208CQNC is a fixed 5V regulator and the SY8208BQNC has a 3V LDO

[SMDFlea]

Re: Lenovo b50-45 dc connector help

Lenovo b50-45 schematic

[Stevie2001]

Re: Lenovo b50-45 dc connector help

I changed the ic and now no amps drawing just 0amps 19v.
Were can it be

[Stevie2001]

Re: Lenovo b50-45 dc connector help

This mofset beeps on both sides
bv4y18 4455
drain and source beeping while it's on beep mode

[diif]

Re: Lenovo b50-45 dc connector help

Test using diode mode, both ways to be sure but it sounds like it could be short.

[Stevie2001]

Re: Lenovo b50-45 dc connector help


This was shorted injected amps and detected this ic heating up checked using thermal also,this was replaced with another one that looks same but different value.


I think this is the main problem,it is beeping on most of the pins with gnd.