Unresponsive white screen on startup
My iMac ("Core 2 Duo" 3.06 27-Inch (Late 2009)), has suddenly started showing a blank white screen after the startup chime once powered on, no apple logo or question mark, nothing. I run both Yosemite and Windows 7 via Boot Camp.
I have tried a number of 'white screen of death' fixes, such as PRAM reset, SMC reset, booting into safe mode, booting into target disk mode, single boot mode etc. The imac is completely unresponsive to any startup commands except the PRAM reset, which successfully restarts the iMac but does not seem to help. Also, holding the option key no longer shows me the available disks.
I'm beginning to think this may be a hardware issue, but if so, what?
Considering taking this along to my local repair shop but I'm a student and can't really afford that, hoping there are some cheap fixes I could attempt.
Many thanks for any insight or advice you guys might be able to offer.