Editing Commodore Plus/4 (section)

== Reliability ==
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The Plus/4 also suffered serious reliability problems due to the TED chip, which was one of the first [[Integrated circuit|ICs]] MOS developed using the newer, lower power [[Depletion-load_NMOS_logic#Intel_HMOS|HMOS]] process. MOS had considerable difficulty getting it to work reliably and TED chips and the 7501 CPU consequently had a high failure rate. Autofire-capable joysticks and improperly constructed 9-pin adapters have also been blamed for damaging TED chips. The C16 had fewer reliability problems than the Plus/4 due to a simpler design with fewer ICs and lower heat output, as well as more room inside the case for heat to disperse.

Like with the C64, the Plus/4 also used an unreliable [[Power supply unit (computer)|power supply]] that was prone to overheating and damaging components in the machine.

This made upgrading to the Plus/4 from the VIC-20 or C64 more expensive, since the user in many cases would have to buy new peripherals in addition to the new computer. It also made the Plus/4 less attractive to new buyers, since VIC and C64 peripherals were more plentiful and less expensive than their Plus/4 counterparts. The street price for a complete C64 system was lower than that of a comparable system based on the Plus/4. Combined with the C64's greater abilities and broader software base, most buyers opted for the older model.