Service and Maintenance 4
U1241A/U1242A User’s and Service Guide 33
8 Ensure that the rotary switch position is aligned with the align marking
on the top case and circuit board switch stay on the OFF position.
9 Then re- fasten the circuit board and the bottom cover respectively.
Troubleshooting
If the instrument fails to operate, check the batteries and test leads,
replace them if necessary. If the instrument still doesn’t function, check
the identification procedures as described in Table 4- 10.
Table 4 - 10 Basic troubleshooting hints
When servicing, use the specified replacement parts only. The Table 4- 11
shows the replacement part numbers.
Table 4 - 11 List of replacement part number
To avoid electrical shock, do not perform any service unless you are qualified to do so.
Malfunction Identification
No LCD display after power ON
• Check the battery polarity and replace batteries if necessary. Ensure that
the replaced batteries are new batteries, it is recommended not to mix old
batteries with new batteries.
No beeper tone
• Check setup mode and verify if the beeper is set to OFF. Then select the
desired driving frequency.
Failed on current measurement
• Check the fuse.
Part number Description
2110-1400 Fast blow fuse 1000 V, 0.44 A (10 mm x 35 mm)
2110-1402 Fast blow fuse 1000 V, 11 A (10 mm x 35 mm)