Error Messages - HP 654 A Series Operating Manual

Error Messages
Power supply failure may occur during power-on selftest or during operation. In either case,
the display may show an error message that indicates the reason for the failure.
Selftest Errors
When a selftest error occurs, it prevents all front panel operation. The display may show
either a power-on error message or a checksum error message.
Power-On Error Messages.
Power-on messages appear as:
En-
Where "n" is a number listed in Table 3-3. If this occurs, turn the power off and then back on
to see if the error persists. It is possible to recover from the EE CHKSUM error (see "Checksum
Errors"). If any other message persists, the power supply requires service.
Table 3-3. Power-On Seltest Errors
Error
No.
Display
Failed Test
FP RAM Front Panel RAM
FP ROM Front Panel ROM checksum
EE CHKSUM EEPROM
E4
(Not used)
E5 (Not used)
(Not used)
E7
(Not used)
E8 SEC RAM
Secondary RAM
SEC ROM
Secondary ROM checksum
ElO SEC SV
Secondary 5 V ADC reading
Ell TEMP
Secondary ambient thermistor
reading
E12 DACS
Secondary VDAC/IDAC readback
Checksum Errors.
If the display shows EE CHKSUM, the power supply has detected an
EEPROM checksum error. A checksum error can occur due to the following conditions:
■ Excessive number of write cycles to an EEPROM (see "Supplemental Characteristics").
This condition, which would appear only after extended use, is not recoverable and requires
service.
■ Loss of ac input power during a checksum calculation. This condition, which is very
unlikely, is recoverable.
You may be able to recover from a checksum error by writing to the EEPROM while the
power supply is in the calibration mode. To do this, proceed as follows:
3-6 Turn-On Checkout
Checkout Procedures