Hello Sylvia, I'm facing the same problem (3 bips and code 20). My workaround is to turn off the power supply completely, wait until the mainboard has no energy and turn on the pc again.
I used the link you provided and here is the data you need (I hope this is the right place to put it)
Reference Number: 0261 1769
Serial number: BQBH234000C5
AA number: AAG39008-400
Processor model: Intel(R) Core(TM) i5-3570K CPU @ 3.40GHz
Memory manufacturer and part number: Kingston KVR16N11/8
Wattage and model of the power supply installed: Corsair CX600, 600W
Model number of the PCI-e devices installed: AMD Radeon R7 200 Series (R7 - 260X - CD) (I'm not sure if this is what you need)
