Samsung r540 no 5v alw present

[garrymc123]

Hi guys

i was looking for the schematic for the Samsung r540 motherboard its the bremen-c rev1.1 (ba41-0122oa hst) but cant find it anywhere...

The problem is the laptop will show its turned on by the light on the power button when pressed but no fan spin no 5v on the USB connectors no power on CPU coils and no display. I Cant find the 5v ic chip on the motherboard. Can anyone point me in the right direction on what power rails to check.

Thanks

[lapfix]

Re: Samsung r540 no 5v alw present

Try this
http://www.s-manuals.com/notebook/samsung_np-r540

[garrymc123]

Re: Samsung r540 no 5v alw present

Thanks for the reply but that's the same one I downloaded the ics don't match up with the ic numbers

[lapfix]

Re: Samsung r540 no 5v alw present

Use a power supply to know how much current use . in some board the 3v/5v comes after power on ..

[emestee]

Re: Samsung r540 no 5v alw present

According to what I read on other forums, you can use Bremen-2L schematics. This is easily findable.

The 5V IC should be next to the 5V coil. You should be able to trace from the coil to the phase output of the IC. On some machines, the standby rails are both generated by the same chip. On Bremen-2L this is U507 (RT8205A).

[emestee]

Re: Samsung r540 no 5v alw present

Edit: RT8205A is usually labelled "CJ-8M" or something similar. It doesn't literally say RT8205A on the chip.