The problem with impact print heads. Needles in the impact print head strike the paper against a metal platen. Because of the constant impact, print heads have determinate life spans. Impact needles are vulnerable to inserted media such as paper clips and staples which can easily cause damage. Impact printers also require more electronics.
Power consumption is very high relative to ink jet.
The impact system necessitates larger motors, larger transformers and larger circuit boards which increase footprint and drive up repair costs. Impact printing is a dying technology. Impact printing has been eclipsed by non-impact technologies such as laser and ink jet in almost every application. Reliability is a key factor behind this trend. Ink jet printers eliminate these problem components.