F Ault Diagnos Tic S - Time Electronics 1044 Manuel Technique

12

7. F ault Diagnos tic s

Introduction
This section gives details of some possible problems and how to correct them.
Fault Check List
If the 1044 is completely dead without any indication of the display working, check
the following
1) Battery condition - replace battery.
2) Polarity of external power unit - reverse connections.
The 1044 indicates an output but there is not an output at the terminals.
1) The output protection fuse has blown. Check why this might have blown, commonly
caused by a signal being applied while still in the source mode. Replace with the correct
fuse.
Current output is not available.
Is there a load connected to the output? If not, current will not flow through the circuit.
The value selected on the display drops when the unit under test is connected.
This is a feature of the 1044 where the 'actual' value is indicated. This is probably
insufficient current drive from the 1044 because the unit under test is loading the output
beyond its 20mA drive capability. Check the unit under test for faults.
It might be due to a low battery condition. Check to see if 'BAT' is showing on the LCD
display.
Fuse replacement
To replace the output fuse slide the rear panel up to its stopping point revealing the battery
and fuse compartment. Carefully remove the old fuse and replace with a 100mA fuse.
Always replace with a 100mA fuse or serious damage to the 1044 could result. Slide the
rear panel firmly closed.
V1.1 09/01/11 P a g e | 12 1044 Technical Manual