Rigol DM3068, Service Manual

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Chapter 5 Troubleshooting & Maintenance RIGOL
Service Guide for DM3068
5-7
Figure 5-3 Transformer Winding
Compare the measured voltages of each winding with the ones in the following table:
Table 5-1 Check list of voltage selector winding voltage
Windings Max(Vrms) Min(Vrms) Typical
（
Vrms
）
Original White-Yellow 132 90 110
White-Red 265 180 220
Vice
Black-Black 10.8 7.3 9
White-Yellow 21 14 17
Yellow-Brown 21 14 17
Blue-Blue 10.3 6.9 8.5
Shielding Yellow-Green --- --- ---
(1) If all the winding voltages of originals are 0, the voltage selector or power
socket may be problematic.
(2) If the original voltage is half or double of the typical value, inaccurate
location might be selected for the voltage selector.
(3) If the vice voltage is less than the minimum, the mainboard may have a
short circuit, please: remove the vice socket of the transformer from the
mainboard (please cut off the electricity before operating) and test the
voltage in vice side; if the voltage gets back to levels, short circuit has
happened to the mainboard, or else the transformer fails.
3. Screen
DM3068 provides a LCD self-check program for users to inspect the light spot,
and dark spot of the LCD, the backlight and the display control circuit.
Inspection method:
Press and hold the second menu key on the left of the front panel and turn on
the meter, after about 5 seconds and until you hear a switch sound of relay, the