iMac display flicker and wavy lines: solved

There has been considerable speculation and discussion about the wavy screens which are found on a number of Summer 2000 iMacs. (See one, two, and this MacFixIt forum thread). In TIL article #31262, Apple suggested that the Macs may need to be repaired. Now Timothy Nitz has provided us with what appears to be the last word. He writes:

"In October Apple released a Service Notice to authorized service providers that identified the culprit as the screws which anchor the RGB video cable. Evidently the original screws are not large enough (or long enough) to provide a proper ground. I had the screws replaced with the proper ones today by an Apple service provider and I can verify that my wavy screen problems are gone completely.

To be specific, after the repair, my iMac no longer displayed any wavy lines whatsoever under the following conditions: When "pulling" down a menu, when playing audio CDs or DVDs at full volume with iSub attached, with the Apple Optical Mouse or new USB keyboard attached, and when using the modem (nor is there any more feedback through the speakers)."

Apple TIL article #31263 also covers this issue. It mentions the screw problem and indicates that the video board may need to be replaced in some cases. (Thanks, Casey Common)