Spontaneous Restarts Briefly After Login

[passmaster16]

I'm currently running a vanilla 10.9.3 build with Clover bootloader on a Sony Vaio Laptop SVE1712bcxb with the following specs:

 

Core i5 3210M

Radeon 7650M

256GB OCZ SSD

6GB RAM

 

Full specs here: http://esupport.sony.com/US/p/model-home.pl?mdl=SVE1712BCXB&template_id=1&region_id=1&tab=manuals#

 

I'm trying to isolate a problem where  machine will occasionally reboot itself without warning within 5 minutes of bootup/login.  Basically I can login to the machine, reach a desktop and start working as normal (launch browser, apps, etc) and then suddenly it will power cycle itself.  It seems to occur more often if I execute a "Restart" from the Apple menu rather than doing a complete shutdown and then powering it back on.  I do not think it's thermal or hardware related as the machine will run perfectly fine most of the time.  In fact if the machine doesn't reboot within the first 5 minutes of login, it's rock solid even after putting to sleep/waking multiple times.  The CPU temperatures are well within spec according to iStat Pro.  The behavior will sometimes occur a few times consecutively and then stop with a "clean" boot.

 

I check the console logs and nothing really stands out in terms of errors or failures leading up to these reboots.  I see two messages that might be relevant:

 

locationd was started after an unclean shutdown

kernel[0]: Previous Shutdown Cause: 3

 

It appears that the shutdown code is always "3" regardless of if I do a restart or shutdown.  It doesn't change even in the cases where the reboots occur.  When the reboots occur, the machine goes straight to a black screen like it was power cycled -- no kernal panic message displayed on screen on in the logs.  On my real Mac (Mac Pro 1,1), the shutdown cause is always 0 so I'm not certain if "3" is to be cause for concern.

 

Any ideas on what might be causing this issue?

 

Thx

Josh