Optoma H27 Service Manual page 41

14. After upgrading the new firmware, please reconnect the H27 power cord and press
"POWER" button to turn on the H27 projector.
Press "POWER", " ", " ", "MENU" to enter the Engineering Mode.
Check the Firmware version and do "Factory Reset".
Notice : Download Failed Message
If you failed to download...
(1) Repeat the procedures of Step3~13.
(2) Check if RS232 cable is connected well.
(3) Disconnect the H27 power cord and then enter the firmware upgrade mode again.
(4) Restart PC/Laptop and try again.
The message shows the firmware version
and its released date.
5-8 H27