ECJohansen

As Dan said, a functioning external display would indicate that the graphics chip is working, and therefore the problem lies with either the cable running to the LCD display or the LCD display itself. If you could take pics of your screen - say with your phone and post them, that would help us. Otherwise, and this is pure conjecture, it sounds like the screen (and/or its assembly is damaged). The screen is either THE most expensive part to replace, or the 2nd most expensive part to replace - the other being the main logic board. Given it’s age, I’m guessing we can assume it’s out of warranty. If you want to do the repair yourself, there is a guide listed here. The replacement is fairly straightforward. It’s the likely cost that you’ll have to consider. Good luck.

You can add a second graphics card to it. I have the same unit, though I'll be upgrading it soon. The second card I installed some time ago, is an ATI Radeon 5770 1GB. I checked, and it's available from Amazon through it's resellers. That card has a DVI port and two mini Display ports. It will drive two monitors simultaneously in addition to your original card driving a single monitor. Shouldn't be a problem. By the way, the card mentioned above is dual width. It'll fit in one slot, but it is huge - full length, full height, and it requires power from the motherboard. Read the docs that come with it. Eric J.

Cheat on this one. Loosen the tape on the back of the display. That gives you more slack on the cable. The connector is pretty standard.

Like others that have commented, this cable is a major PITA. I used both a headlamp to illuminate the area, and the iPhone’s Magnifier app to zoom in. The connector on the motherboard is flat, low profile and characterized by a thin narrow slot. The key to removing the cable is to slide the cable out, (after flipping that bar forward). Re-attaching the cable is the same - carefully sliding the cable into that slot, while keeping that bar pulled backward, until the cable was in place.

For me, this was the most difficult part of the hard drive replacement. I spent more time on this than anything else.

Use either a spudger or a small flat head screwdriver to loosen the sides of the connector. Then use small needle nose pliers to disconnect the cable. It’s easier than trying to wedge your hand in there.

As others have posted here, Do NOT let gravity assist you. Put the iMac on it’s back when doing the remaining steps. Also, use some type of hook to assist you in terms of lifting out the display assembly. Expect some resistance, since it does weigh a few pounds. Also, as you’ll see in the next step, you can help yourself by using something to brace it at each corner to keep it lifted. Some have suggested chop sticks, bic pens, etc. Use something approx. 4-5” in length. That will give enough clearance, and not put strain on the cables.

Thanks for the instructions. Before doing this the first time, suggest to everyone, read through at least twice. This is the easiest step, as you’ll soon see. As for removing the glass, USE suction cups, either the ones the sell here, or others. DON’T skimp. Also wear gloves when handling the glass. Don’t take chances.