VR_ON signal mising in acer 4830.

[nazrul145]

Hello friends, i have problem with acer 4830 with no display. its shutdown after 5sec. i have checked processsor is not hot. so i check cpu core but no core voltage found. also its VR_ON not coming from SIO. now i m confused is it sio fault or another point should check for find vr on from sio.
PL13 PL14 resistance to ground 447. pls suggest me why sio not release vr-on signal. thanks advance............

[dj_ricoh]

Re: VR_ON signal mising in acer 4830.

i`ll suggest to swap it!
its only 2$ free shipping and maybe you can find it on a scrap board. its ENE KBC
you know what i`ll order one to i`ll never know when i`ll need it.

[whaldsz]

Re: VR_ON signal mising in acer 4830.

Hello friends, i have problem with acer 4830 with no display. its shutdown after 5sec. i have checked processsor is not hot. so i check cpu core but no core voltage found. also its VR_ON not coming from SIO. now i m confused is it sio fault or another point should check for find vr on from sio.
PL13 PL14 resistance to ground 447. pls suggest me why sio not release vr-on signal. thanks advance............

VR_ON won't give 3.3v if there is an over-voltage/over-current situation.

Here's what you should do:
1. Check first if pins 6, 14, and 110 is 3.3v. If one of these is low, you probably have a problem with your PCH.
2. Check the resistance of PL12, PL13 and PL13. If the resistance is very low, less than 3 ohms, there is a short somewhere here, probably MOSFET, PCH or CPU may need reballing/replacing.

Post back your results.

[nazrul145]

Re: VR_ON signal mising in acer 4830.

pin 6,14,110 IS LOW WHEN POWER UP. IS IT PCH PROBLEM OR BIOS.

[nazrul145]

Re: VR_ON signal mising in acer 4830.

Now this motherboard is ready. Problem found in 5v line. I have check every coil and no voltage found without 3v. But power up laptop and no display. Now 5v is ok and motherboard is ok.