Owandy Radiology i-max touch, Service Manual

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SERVICE MANUAL
Maintenance and servicing
I-Max Touch 7-29
7.2.1. kVp
Use a multimeter (R input >= 10M

) in working conditions VDC and end
of scale 5/10V (maximum value 4.3 V); position the cold pole on TP45
(GND) and the hot pole on TP44 (kV) on the Generator board (A10). Set
the following parameters in CEPH mode: 60kV-6mA-3s.
Perform an exposure and considering that the ratio between the value on
the voltmeter and high voltage is 1V= 20kV, verify that the value
indicated by the multimeter ranges from 2.85

3.15 V (3V

5%).
Should this last value be outside the specified limit, detect the "set kV"
voltage supplied by CPU, connecting the voltmeter between TP45 GND
test points and TP46 kV (set nearby X57). The value on these points
must range from 2.7 and 3.3 V (3V+3%). If it is out of tolerance replace
the Generator CPU board (A9), otherwise replace the Generator board.
Measured values for different set values are contained in the following
table.
kV Nominal
value
Minimum
value
Maximum
value
60 3 2.85 3.15
70 3.5 3.325 3.825
80 4.0 3.8 4.2
86 4.3 4.085 4.515
If all measures are within the specified range, and there is an evidence of
a performance loss, measure the high voltage supplied by the tubehead,
and the exposure time using a non-invasive kilovoltmeter with < +3kVp
tolerance. The high voltage value must be within 8% of the set value,
while the time value must be within 10% of the set value. If the voltage is
not within the expected range, replace the tubehead; otherwise replace
Generator CPU board.