I have bought this dell r710 used, it used to boot, have replaced fans due to errors, I go back home today to find that it will turn on for a split second then power back off the LCD 'kinda' works and I managed to find out that the CMOS battery is dead but this had happened already and it would still power on. I hope I just have to replace it but I am making sure so I don't waste any money, please help.
To fix the Dell R710 no boot issue, press the power button for 15 to 20 seconds, and reassemble the hardware of your device. Unplug all the wires and cables from the system and then plug them in back. If you still face the problem then you can go for replacing the device.