Epson 10020 - Manual (Page 155)

If the computer finds a fault in the main board, it stops and
displays an error message such as this:
10n-System board error
where n is a number from 1 to 8 that represents the specific LSI
circuit causing the error. Give this error number and message
to your Customer Care Center.
If an I/O ROM checksum error occurs, you see this message:
nnnn0 ROM error
where nnnn is the number of the segment of the bad I/O ROM
on an option card.
Give the error message and number to your Customer Care
Center.
Timer and CMOS RAM Check
After the computer successfully completes the system device
check, it checks the timer and CMOS RAM. if the
information contained in the RAM does not match the actual
system installation, it displays this message:
161-System options not set
(Run SETUP in DIAGNOSTICS)
If the system clock has not been set, you see this message:
163-Time & Date not set
(Run SETUP in DIAGNOSTICS)
The information stored in the CMOS RAM must be corrected.
To do this, run the Setup program provided on the Reference
diskette. See “Running the Setup Program” in Appendix A for
instructions.
C-2 Power-on Diagnostics