Mitsubishi SD200U, Service Manual

Page: 40 / 108

- 1 -
DIAGNOSIS FLOW CHART
Image system
Using the shielding sheet metal as GND is allowed when checking the voltage waveform or terminal voltage.
When replacing the PCB or the optical unit, follow the instructions on the service manual.
Is the lamp lit?
Is the indication on LED normal after POWER ON?
(POWER : Green, LAMP/TEMP/STATUS : Green)
Is the proper video signal inputted?
Or is the image projected correctly?
NO
YES
YES
NO
YES
NO
Malfunction of IC400 or subsequent circuits
Check the voltage waveform of connector
SF.
Check the video signal circuit around IC400
and IC4A0.
* If the above voltage waveform is normal,
malfunction occurs on the FORMATTER
UNIT or OPTICAL UNIT.
Replace the FORMATTER UNIT.
Replace the OPTICAL UNIT.
When a black-and-white still image is
displayed on the screen, the C/W-J12 cable
may have been broken.
Malfunction of the analog/digital circuit around
the input terminals of the computer.
Check the video signal circuit around J600,
J601, IC600 and IC650.
Check the synchronizing signal circuit
around J600, J601,IC501, IC502, IC503
and IC540.
Malfunction of the circuit around the video
input terminal.
Check the display in the video mode 1, 2, 3,
and 4.
* When an image isn’t displayed in all the
video modes
Check the video signal circuit around J2F0,
J2F2, J2F3, IC2F0 and IC2A0.
* When an image isn’t displayed only in the
video mode 1, 2, 3
Check the digital signal circuit around IC240.
* When an image isn’t displayed only in the
video mode 4
Check the digital signal circuit around IC200.
Malfunction occurs on the digital signal processing circuit.
Check the digital signal circuit around IC400.
An image is not
projected properly.
Is the menu projected
normally?
Is a video image
projected normally?
Is a image from the
computer projected
normally?
!
!
!