Sorry you are having trouble. But, it may have a solution. Two things to try:

First remove any CF card. Make sure you have solid AC power of the right voltage.

1) Read the "Start-up Options" section on page 152 and 153 of the UM. Try the PROGRAM and setup options. If the problem is caused by the unit being in a bad state, one of these will fix it.

2) If this fails, upgrade the unit to the latest version (see Downloads section of H8000 product page on Web Site). If the upgrade is performed sucessfully, but does not solve the problem, there is probably a hardware problem and the unit will have to come back.