Service Manual
Service Instructions
Siemens Ltd. Med India
Version 6.0
Copyright
SIEMENS LTD. All rights reserved. For internal use only
7-7
V24 (red) lights up on D915 and CODE no. will be displayed on 7 segment display.
This will alternate with the kV and mAs values selected.
7.7
Checking the Control Voltages
When the unit is ON relay K2 on D920 are ON.
SMPS placed in the Inverter module gets supply, Measure the DC voltages at X15
connector of D915 PCB.
Pin No.
Signal Name
Input/Output
max. permissible
voltage/current
1
D gnd
Input
0V
2
-nc-
-nc-
-
3
D gnd
Input
0V
4
DC supply
Input
+ 5V
5
DC supply
Input
+15V
6
A gnd
Input
0V
7
DC supply
Input
-15V
-nc- = No Connection
7.7.1 Checking the Intermediate circuit voltage
Depending on the supply voltage, a value between 250 to 350Vdc must be measured
with the digital multimeter across the parallel capacitors C1,C2,C6,C7 and C9(if
present) in inverter module.
7.8
Checking & setting the maximum main inverter frequency
Turn the Unit OFF.
Place the ST link on D915 so as to short the two terminals.
Make the unit ON. The unit enters SERVICE mode.
In the service mode of the unit ,select Prog 7 by using the KV switches.
On activation of this mode by pressing the DL-serv Key , the display indicates
Adj
F
Press the Radiographic exposure switch and monitor REG on Digital storage
Oscilloscope at Reg Test Points.
The display indicates
F
On
And max. Inverter firng frequency will be displayed on Oscilloscope.
Adjust REG for 9.2 kHz
±
0.3kHz by using P4 on D915 card
After adjusting the frequency switch off the unit and remove ST link on D915 card .