Emu XL-7 & MP-7 User's Group

It's worth noting that many of these emu boxes made use of bootleg capacitors in the power supply (as did many computers of the same era.)  The caps can leak and cause damage to circuit boards, and as they fail they often cause erratic behavior of the machine.  For most members of the P2K and XL7 family, a power supply recap is highly recommended.  I have seen a few late model P2K boxes that have an updated power supply, and it's possible some of the later Command Stations do as well.  But as a general rule, a power supply recap is the way to go.