Tror den er brændt af på den 12Volt rail, da dit Radeon 4850HD x2 skal have en PSU der giver minimum 15A ud på 12V siden og Psu`en skal være minimum på 450W - helst 550W
ATI Radeon™ HD 4850 System Requirements
* PCI Express® based PC is required with one X16 lane graphics slot available on the motherboard
* 450 Watt or greater power supply with 75 Watt 6-pin PCI Express® power connector recommended (550 Watt and two 6-pin connectors for ATI CrossFireX™ technology in dual mode)
* Certified power supplies are recommended. Refer to
http://ati.amd.com/certifiedPSU for a list of Certified products
* Minimum 1GB of system memory
* Installation software requires CD-ROM drive
* DVD playback requires DVD drive
* Blu-ray™ playback requires Blu-ray drive
* For a complete ATI CrossFireX™ system, a second ATI Radeon™ HD 4850 graphics card, an ATI CrossFireX Ready motherboard and one ATI CrossFireX Bridge Interconnect cable per graphics card (included) are required