Olympus OEP-3, Service Manual

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6-2
OEP-3 V1 (UC)
Input Block
In the input block, the flow of a signal is as follows:
Signal input terminal (IF-764) - ADC (VPR-63) - DRAM (VPR-63)
If a trouble is judged to occur in the input block, check the state of a video trouble fully. For fine
symptoms in dots, a trouble may occur in a digital processing system [ADC (around IC350 to IC352) -
DRAM (around IC801 and IC802)]. In other states, a trouble may occur in an analog processing system
[IF-764 - Decoder (around IC203) - ADC].
In the trouble of an analog processing system, the place where a trouble occurs can be more narrowed
down by checking the state of each signal (VIDEO, S-VIDEO, and RGB).
Monitor Output Block
In the monitor output block, the flow of a signal is as follows:
DRAM (VPR-63) - Encoder (VPR-63) - Signal output terminal (IF-764)
Like an input processing block, it can be supposed to some degree by the trouble state whether the block
where a trouble occurs is a digital processing system [DRAM - encoder (around IC407)] or analog
processing system (encoder - IF-764).
The place where a trouble occurs can be more narrowed down by the state of each monitor output signal
(VIDEO, S-VIDEO, and RGB).
Print Output Block
In the print output block, the flow of a signal is as follows:
DRAM (VPR-63) - Masking (VPR-63) - Head control (PRT-13) - Thermal head
The data output from DRAM on the VPR-63 board is input through the masking circuit (around IC902
and IC903) on the VPR-63 board to the head control circuit (around IC217, IC222, and IC226) on the
PRT-13 board.
Moreover, the print signal that was converted from serial to parallel in the head control block is output
through a cable to the thermal head.
6-2. Mechanical Troubleshooting
6-2-1. Outline
The trouble in the mechanical deck of a printer is mainly classified into the following.
1. Paper feed trouble such as incorrect paper feed or overlapped paper feed
2. Paper delivery trouble such as paper jamming occurring after print
3. Print trouble appearing as the result of print
Examples are given for each trouble, and the designation of a place and the way of solving are described.