If the error occurs the system boots exactly to the point where BIOS/Video-BIOS want to identify the display. Since the EDID data is corrupt the system locks up, so you don't even have a chance booting with an external monitor attached. So you have an expensive brick that keeps your desk at moderate temperature (to quote Jonathan).
The only way to "repair" this requires opening the housing and will make the customers warranty void. So the process is contacting the vendor and letting someone from them repair it with the proper tools.
BTW: This issue seems to be happening on drivers of the 180.xx series only. Debian 5.0 with packaged 173.xx drivers are not affected.
Rainer (that "bricked" and repaired his H270 several times)