CD & DVD ROMS, KEYBOARDS, FLOPPY, SOUND DEVICES, USB PORTS, PARALLEL & SERIAL CONNECTIONS, TOUCH SCREENS, MOUSE PALLETS AND ANY OTHER I/O DEVICES AS ANY OTHER FUTURE PORT DEVICES. There may be further issues than those listed on machines that don't turn on or that only turn on as far as BIOS (eg: cuts out after a few minutes or dead BIOS battery) also may have further signs of wear and tear or need a good clean.
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