Villa Rotograph EVO, Service Manual

Page: 164 / 223

SERVICE MANUAL
Troubleshooting
(Rev. 1) Rotograph EVO 8-73
•
Non-exposed area in the lower-central part of the image
If the problem appears as shown in point "5" of the previous Figure
8-12, it indicates that there has been interference between the leaded
apron worn by the patient and the X-ray beam.
Remedy:
Properly position the leaded apron (it must be worn well tight to the
shoulder and neck of the patient) then carry out a new examination.
•
The teeth rows are overexposed
As already described, if the tongue is not positioned against the
palate during the exposure, it will create an air chamber between the
tongue and the palate; this air gap creates a less absorbing area that
overlaps the teeth, often in the apex area. This area is identified with
reference "1" in Figure 8-12.
Remedy:
Ask the patient to position the tongue against the palate during the
exposure.
•
Presence of bright spots or rows
If these artefacts are always in the same position on the film, they are
probably generated by dirty or damaged intensifying screen.
Remedy:
Check and clean/replace the screen.
•
Film with images of the cassette locking device
The cassette has been fit into the machine on the wrong side. As
general rule, the film is underexposed due to the presence of the
secondary lead shielding.
Remedy:
Repeat the examination by properly fitting the cassette into the
machine.