Testomat EVO TH CAL - Page 73

Servicing and maintenance
73
Exchange
If not all three green LEDs on the motherboard light up, at least one
fuse is defective. The supply voltage unit is next to the LED, which
indicates its status.
You require:
 A Phillips-tip screwdriver
 Flat-tip screwdriver
 Replacement fuses
To find the defective fuse, proceed in accordance with the trouble-
shooting scheme.
Troubleshooting scheme:
Step
LED / lamps
Action
1
Open up the device at the top
and switch it on. Does at least
one LED light up?
No → Step 2
Yes → Steps 5, 6
2
Does the power supply work
and is a permissible voltage
measured between N and L?
No → Service
Yes → Step 2a
2a
Is the voltage measured in
step 2 also measured be-
tween n and l?
Yes → Step 4
No → Step 3
Green LEDs on the
motherboard:
24V
12V
3.3V
Observe ESD safety
precautions! See the
information on page 8