Error
No.
Display
Table 3-3. Power-On Selftest Errors
Failed Test |
| Error | Display |
|
| No. |
|
Failed Test
El E2 E3
E4
E5
E6
E7
FP RAM FP ROM EE CHKSUM PRI XRAM PRI IRAM PRI ROM GPIB
Front Panel RAM
Front Panel ROM checksum
EEPROM
Primary external RAM Primary internal RAM Primary ROM checksum GPIB R/W to serial poll
E8
E9
E10
Ell
E12
SEC RAM SEC ROM SEC 5V
TEMP
DACS
Secondary RAM Secondary ROM checksum Secondary 5 V ADC reading
Secondary ambient thermistor reading 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 "Nonvolatile Memory Write Cycles" in "Supplemental Characteristics" tables). 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:
1.Enable the calibration mode by pressing 
.
2.PASWD will appear on the display.
3.Press the number keys corresponding to the password, followed by 
. The Cal annunciator will go on.
Note On new equipment, the calibration password corresponds to the 
). See "Appendix A - Calibration" for more information about the calibration password.
4.Save any operating state (for example, press 
).
5.Turn the power off and then back on.
A normal display free of error messages should appear. If not, the power supply requires service.
Runtime Error Messages
Under unusual operating conditions, the VOLT or AMPS display may show +OL or
Display
EEWRITE ERR SBUB FULL SERIAL DOWN STK OVERFLOW
Table 3-4. Runtime Errors
Meaning |
| Display |
EEPROM status timeout |
| UART FRAMING |
Message too long for buffer |
| UART OVERRUN |
Failed communication with front |
| UART PARITY |
Front panel stack overflow |
|
|
Meaning
UART byte framing error Overfilled UART receive buffer UART byte parity error panel
