Earlier this year, the four year old 24″ iMac in my office starting getting horizontal lines on the display. It started with one line near the bottom of the screen, worsened with another line appearing and then expanded to the entire screen having problems with wide horizontal bands.
Google searches led me to believe it was the GPU (Graphics Processing Unit) overheating due to the internal fans not running fast enough. Apparently Apple had chosen to set the fans speeds lower to make the unit run quieter at the risk of damaging hardware due to overheating.
I downloaded some free software to increase the fan speed, buying me some time to consider a repair. I took my iMac to a local computer repair shop that offered to diagnose the problem for free. They actually convinced me it was the LCD display, not the GPU by plugging another display (using the DVI to VGA adapter) into it and that worked.
As hard as it was, I declined their offer to go ahead and replace the display. I wanted to research what options I had online for screen replacements. I used the serial number of the iMac on the Apple Support site to verify its model number (early 2009). Then I did some searches to locate the part number of the LCD which helped me look for listings on Ebay. It took a couple of weeks of searching before I found a new posting for a used display in great condition for $125 with free shipping. The seller was a graphics designer and was having color tint problems with the display that was impacting his business.
While I waited for the replacement, I did some additional Google searches for procedures on how to replace the LCD display. One of the key tools I would need where suction cups to remove the display cover which is actually held in place by strong magnets. I managed to find a couple on sale at Harbor Freight for $2.95 each.
Putting in the replacement display wasn’t too difficult. The suction cups made it a snap to get the screen cover off. Unhooking the two connectors from the bad display was straightforward. The only tricky part was cleaning the replacement display with a microfiber cloth to remove the marks from the bubble wrap packaging used to ship it. Once I had it back together, then I had to color calibrate the new display to remove the yellowish tint.
Aside from the original problems with the display, there wasn’t anything else wrong with my iMac so it was worth looking into the screen replacement. A new display from Apple with labor would have been $400-$500. To have an authorized Apple Service provider replace the screen would have been at least $120 for a total cost of $345. So I saved at least $120 by doing the work myself. -MC