While there are a number of reasons that an NEC projector would exhibit an LPSU (Lamp Power Supply) message, there are two that are very common.  The NC1200/2000c projectors feature an external circuit breaker that protects the LPSU.  Although NEC specifically recommends that this be left on, many exhibitors routinely shut this off regularly to save power or to conserve the fans that would otherwise be running 24/7.  Immediately above the LPSU breaker is a single physical power switch labelled PJ Power.  While this switch is white on the majority of projectors, earlier models shipped with a black switch.

If the PJ Power switch (a/k/a Projector Head Power Switch) is turned on without the LPSU Power switch having been turned on first, the projector will emit a loud beep and the error message LPSU will appear on the LCD screen.  This can generally be resolved by simply turning on the LPSU switch.

The other instance is related but a little more complex.  The NC1200/2000 projectors can be wired to run off of a single 220V single phase feed, this is the factory default, or be split to run off of a 220V feed for the LPSU and 120V feed for the electronics (preferred).  If the latter method is used, it is possible for the electronics to be on, with beeping and error message as above, but with no power available to the LPSU.  Check the 220V breaker feeding the projector and, if the projector is connected via a plug, make sure that it is seated securely in the socket.

If the above conditions have been met and the problem persists, the next step would be a complete power cycle of the projector.  If the problem continues to persist, your service company should be contacted.

Please note that NEC error messages are fairly verbose.  They are formatted with a numeric error code, a short description, and sometimes one or more parameters such as:

Please relay the entire message to your service professional as it greatly assists with the diagnosis.