Notebooks & Netbooks

[ctk2112]

I have an Acer V3-571-6849 that was presented to me with no power.

I determined that it should be a motherboard problem and purchased a "good used" motherboard and installed it.

The laptop booted up fine after replacement, but while checking for malware, I noticed it shut down by itself.

Upon boot up, eventvwr showed only a power event and no other blue screen error.  I have since seen it shut down while watching and no blue screen is even briefly displayed.

I removed the HDD and booted to a CD and performed RAM testing.  During the Ram test, it shut down again, so I know it is not an operating system issue.

I have used a hard-wired temp gauge on a multimeter and a laser temp probe and I find no area on the board or chips that exceeds 120F.  Most areas are at 95-99F.  The hotest area on the Processor is 117F.  I believe this is normal.  The fan is spinning all the time.

I am going to replace the Ram chip just in case.  Any ideas where else to look?

Thanks in advance, 

Charles.

P.S.  I have 87 Acer desktops and 10+ Acer laptops and have had no serious issues until this one.

[JackE]

I'd guess a current leak to ground somewhere that trips the system off. The usual suspects would be screws (loose or otherwise misaligned) near the charger jack, MB trace lines touching a ground, broken conductors in the video ribbon usually in the tortuous path it takes thru the hinge area, and improperly-seated connectors. Those'd be my first guesses from afar.

Jack E/NJ 

[ctk2112]

Thank you very much for the reply.

We have tested today extensively without any cables plugged in (except power), including the video cable and also pulled the power switch ribbon cable after powering it up.

It still shuts down after about 20 minutes.  I can't beleive it is anything but a failing MB at this time unless I am missing something.

Best regards,

Charles.

[JackE]

Double/triple-check screws affixing MB are seated and not touching a trace line, pin or any ungrounded path on the MB. An internal breaker is tripping for a reason and it's likely not simply a faulty breaker.

Jack E/NJ

[ctk2112]

We pulled the board out of the case and only had the power connector attached, so it can't be a screw, not even the power switch board was left attached.

I know it could be a bad processor, but I have never run into that and from what I have heard, usually that is a hard failure.

Any other suggestions before I try to get a replacement MB?

Thanks again,

Charles.

[JackE]

As a last ditch effort, you could try a MB solder re-flow. Nothing lost except for a bit of time in the toaster oven. 8^)

Jack E/NJ

[ajay_1988]

Dear ctk2112,

Could it be possible that your system is shutting down due to over heating issue.

Did you try to change the thermal heat sink paste?

If not lets give it a try and see if it works...

Post back your result

[yuryv]

What part number systemboard is it?

[JackE]

Q5WVH LA-7912P

http://www.amazon.com/Acer-Aspire-V3-571-6643-Motherboard-LA-7912P/dp/B00BSEYWGU/ref=sr_1_1?ie=UTF8&...

Jack E/NJ

[yuryv]

That should do it!