Faulty capacitors are causing video failure and periodic system shutdowns in some Apple G5s. The red arrows points to several swollen capacitors on the back of this new iMac. (Not all of the capacitors are bad). When functioning properly, capacitors temporarily store electrical charges and release them as needed. After the problem crops up, the system log shows the problem as a "Graphic Chip Error." The only way to fix the problem, according to Apple, is to replace the mid-plane.