06-15-2014, 04:31 AM
Join Date: Apr 2008
Location: Chepstow UK
OS: Triple Boot win10pro 64bit /win7 Pro 64bit/ winXP Pro SP3
Please help me with a very frustrating and strange ‘Power on and Shutdown’ issue.
Viglen Genie Executive 965 pBTX (Small Form Factor Desktop PC)
System Board - Asus P5B-BVM DO/S rev 1.02G
AMI BIOS v2.58
Intel Core 2 Duo 2.13GHz
2GB DDR3 Memory
160GB Seagate HDD
Onboard graphics only.
PS2 keyboard and mouse only (no peripherals)
Windows XP pro only installed.
The issue is not that easy to describe but here goes!
After plugging in the power cable the LED’s on the system board and front panel are lit, solid green, then the PC switches on by itself for a few seconds and then off.
It will then either stay off or switch back on after a few more seconds and then boot up.
When it boots up the two CPU fans are running 100% and will continue to do so until a (soft) restart is done. It will then operate normally with the fans running quietly. When the PC is shutdown via Windows it will revert to starting on it’s own and repeating the cycle above !! (so to switch off PC, power has to be unplugged at this point)
If the PC is shutdown via windows with fans running 100% (without soft restart done) windows will shutdown, monitor goes into sleep mode but PC remains powered on. Holding in power button (to switch off) has no effect and PC has to be unplugged.
Things I have tried in no particular order: (both with fresh install of Windows XP only and also with all required drivers)
Tried it with ‘barebones’ set-up without front panel components connected (including power switch) etc
Substituted the Power Supply for known good one.
Substituted the Hard Drive for known good one.
System file check sfc /scannow
Re-seated and tested the memory.
Tried with BIOS Default setting.
Cleared the CMOS via jumper.
(This caused a message (summarised) ‘Intel Broadwater-G PCI Accelerated SVGA BIOS’ and ‘DECOMPILATION OR DISASSEMBLY PROHIBITED’ to appear on next boot and I could not gain access to the BIOS until CMOS was cleared for a second time and then selecting F10 on next boot)
Fitted a new battery on System Board.
In Windows Registry have tried changing the value (1 or 0) in the PowerdownAfterShutdown’ area. (forum suggestion)
Have tried disabling automatic startup if windows detects a fault.
Have checked in BIOS that power on from PCI devices and LAN is disabled (default setting) (forum suggestion)
I am reluctant to flash the BIOS and would need specific instructions to do this as I could end up going from a ‘difficult to start PC’ to ‘a completely non-working PC’ !
Will be grateful for any help on this.