HP INDIGO 5000 computer shut-off

Hi guys i have a weird problem when i start the machine some times when its not running in stand- by or sleep mode the computer turn of by it self with the UPS in the same time with a bip alarm (mean no power to UPS)
When i try to reboot the machine every things go normal until it aske me to turn on the machine.. once i turn it on same problem happen right a way the UPS and computer turn off and than turn on by itself
NB: when the computer and UPS turn off the main machine still in power with drawers but the machine switch button is in off mode
Any idea please

 

Just bypass UPS and try. If everything will be good, replace UPS.

 

When i bypass the UPS it work fine the problems , i want to know if it is from the board or battery i leave the UPS for a week disconnected and keep measuring the voltage it's 38 v ?

 

Replace battery

 

i will can you tell me the right voltage ?