Mac Pro :: Unable To Use Dual Monitors / No Signal On Both DVI ChannelsJan 10, 2009
After lots and lots of reading I went for flashed Sapphire 4870 512 off eBay for my Mac Pro 1,1 running SL 10.6.2, with two Viewsonic VP2030b. The guy selling the card had sold flashed cards before and had 100% feedback, said the card worked with dual monitors and supported SL. Got the card, installed it without a problem, but could not get it to work with both monitors.
Second monitor said no signal on both DVI channels. Checked all the wires, reinstalled, rebooted, no luck. Plugged both into my 7300GT, no issues at all. At one point, I got the left monitor to boot as the extended desktop, showing the dock but not showing the HDD or icons (which should be on the right screen), but the right screen still showed no signal and was black. Used the gather windows botton in the display preferences to see if adjusting settings helped, still nothing. Detect displays button was no help either. Is this a compatibility problem on my end or a flashing problem on his? Contacted him and he said he had no issues with his MP 1,1 and two 20" Apple displays.