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• M1 (IC001)

When the shutter is pressed, the HI microprocessor which detects the switch input notifies the main microprocessor (IC602)

that the shutter has been pressed by serial data.

Using the serial data output from the main microprocessor, M1 (IC001) stops the output of the image data input from DSP

(IC303) to the VRAM (IC002).

It then outputs the VRAM image data to the JPEG section from the PIX0 (Pin *¡) to PIX7 (Pin *•) terminals.
During image data compression, the H signal is input to the COMP terminal (Pin (¢) from the JPEG decoder (IC503).
(However, the H signal is also input during idling.)
About 2 seconds after shooting, The M1 sets back into the standby mode, and outputs the image data from the CCD to the

VRAM.

• LCD Display Circuit, Video Output Circuit

The operations of the LCD display circuit and video output circuit after M2 (IC101) are the same as during the standby

mode.

In these circuits, the data stored in the VRAM (IC002) is displayed on the LCD and video output every 1/60 seconds. When

the shutter is pressed, the LCD images and video images stop because the RAM data is not rewritten for about 2 seconds.

• JPEG encoder/decoder (IC503)

IC503 is connected to the main microprocessor (IC602) by the address bus and data bus. Register settings are performed by

the main microprocessor.

JPEG data compression control of IC503 is performed by M1 (IC001). The operation clock (12 MHz) is also input from

M1.

Inside the JPEG encoder, the video data is compressed to generate the cell data.
Image data is compressed by performing DCT calculation every 8 x 8 pixel block input to PIX0 to PIX7 terminals to

quantize the data.

The compressed data is then output from VD0 to VD15 to the DRAM (IC604).

When the data line of the JPEG encoder becomes disconnected, this may occur. In such cases, check the soldering of the

data line.

• DRAM (IC604)

4 Mbit DRAM for the work area during JPEG compression/extension.
It also serves as the buffer until the compressed data is written in the image memory (IC771).
Consequently, when continuous shooting is performed, several sheets of compressed image data (four in the standby mode)

will be written in the DRAM. These data are then transmitted to the image memory (IC771) in order.

• Image memory (IC771)

Memory for preserving still images shot and compressed. With a capacity of 32 M bits (4 MB), it keeps the data even when

no power is supplied to the unit.

Other than the image data shot, the image memory also memorizes electrical adjustment values. When replacing the image

memory, be sure to set the adjustment default value using the test program.

When the SY-01 board is replaced, the user data recorded in the image memory will be lost. In this case, it may be possible

to read the user data by removing the image memory from the damaged board, and attach it to the new board.

If the AC adapter is disconnected immediately after shooting, the image data may not be recorded properly in the image

memory and as a result become faulty.

If the power is cut especially while recording the management information area of the image data, it may become

impossible to read not only the shot data but all the data stored as well.

Consequently, don’t disconnect the power source after shooting while the shot LCD images are still.
This is not a problem when turning OFF the power by rotating the function dial because the power will go OFF after the

images have been recorded in the image memory.

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• Main microprocessor (IC602)

Started by the XMRST (microprocessor reset) signal input via the buffer (Q601, Q602). The operating clock is the 16 MHz

(X601) for the microprocessor.

Performs data communication with the HI microprocessor and camera microprocessor only with the serial data bus (Pin 21,

SDT0, Pin 23 SDT1) to control operations.

Communicates with the DRAM (IC604), ROM (IC605, IC606), address decoder (IC607), JPEG encoder (IC503), and M1

(IC001) through the address bus (A1 to A19) and data bus (D0 to D15) to control image processing.

Because it can not control operations using only the microprocessor terminals, it transmits some data to the address decoder

(IC607) and outputs the control signals using that terminal.

• Address decoder (IC607)

Decodes the address signal (A17 to A23) input from the main microprocessor, and outputs the chip select signals (JXCS,

MCXCS, XIRCS) to each device.

It incorporates a register as a expansion port of the main microprocessor, and controls each device by setting the data from

the data bus (D8 to D15).

The address decoder also outputs the reset signal of the camera microprocessor (Pin $ª, XCRST), up/down reversal signal

of the liquid crystal display (Pin $¶, XREVV), and shutdown signal (Pin $¡, X23SD) of the RS232C driver (IC601).

It also reads/writes the image memory (IC771) using the data bus (D8 to D15) and five control signals (Pins 20 to 24).

• Mask ROM (IC608), EEPROM (IC606)

ROMs recorded with the microprocessor operation program.
Either one is mounted on the board.

The main microprocessor program is stored in the EEPROM (IC606) or mask ROM (IC608). As these two ICs have a

different number of pins, only one is mounted on the SY-01 board.

The EEPROM is mounted in the initial production, but the unit will operate normally even if replaced with the mask ROM

(interchangeable).

The mask ROM pattern (48 pin) and the EEPROM pattern (56 pin) are stationed with moving a little bit. Take care when

you solder them.

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When the flash button is pressed, charging for flash starts. The charging time differs according to the state of use of the

flash, but is 12 seconds at the longest. (Detected by COMP1.)

When the shutter is pressed, flash is lit at the same time.
At this time, the light reflected from the subject is detected by the light adjustment window between the lens and flash

unit.

When this reflected light reaches a certain level (detected by COMP2), shooting is performed, and flashing is stopped.

Charging may take more than 10 seconds when the unit is used for the first time or left unused for a long period of time.

However, it will normally take about 5 seconds immediately after using flash.

Because only little flash voltage is used when the surrounding is bright, it can be charged at an even shorter time. On the

contrary, it may take more than 10 seconds when a low voltage lithium ion battery is used.

Do not dirty the light adjustment window with fingerprints or pasting seals, etc.

As some light will pass through the light adjustment window even if it is covered with fingers, the screen will not

become completely white by overexposure.

If the screen becomes completely white using the flash, the flash adjustment circuit or shooting circuit may be damaged.
The image may also become completely white if the shooting distance is less than 50 cm.

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When repairing the flash board, be sure to discharge the capacior (C609) as follows.
As the charged capacitor has a high voltage (approx. 300V), it must be discharged to avoid hazards. Even after full

emission of the flash, about 50V will remain in the capacitor.

When short-circuiting without a resistor, about 150A current will flow instantaneously, causing possible damage to the

board. Therefore, be sure to discharge the capacitor completely using a short-circuit tool.

• Discharging the capacitor
1 Attach a small clip to both edges of the 1 k /8W (P/N, 1-207-975-00) resistor to construct a short-circuit tool. Wind

insulation tapes completely around resistor wires to prevent electric hazards.

2 Be sure to connect the clip of the short-circuit tool to the minus side of C609 first.

(When connected to the plus side, it may be short-circuited accidentally.)

3 Check that your fingers and hands are not touching the metal parts of the short-circuit tool, and connect the other clip

to the plus side.

Perform flash adjustment in a dark room without reflecting objects nearby or using a flash adjustment box that is painted

black and not shining inside. Refer the service manual on how to construct this box.

Pressing the flash button will start flash charging.
When pressed, the HI microprocessor detects the input, and the STBOCHG signal (Pin !∞) is output in H. As a result,

Q601 and Q602 of the ST board turn ON, and the UNREG voltage is supplied to the oscillation circuit of the ST board.

The oscillation board composed of Q603, D602, and T601 generates approximately 700Vp-p voltage. This voltage is

rectified by D603 and used to charge C609.

This voltage charged to C609 becomes the flash emitting voltage.
The actual charge voltage is about 300V.
During or after charging, the LED is lit or blinked. This is done by turning ON Q304 with the LEDON signal (Pin!• of

IC301) of the HI microprocessor.

The charge voltage and reference voltage are compared to detect the end of flash charging.
For the reference voltage, the 3.2V for the HI microprocessor of the HV board (IC301) is used.
This voltage is supplied to the ST board when Q308 and Q306 are turned ON by the H signal of the S+3.2V ON signal

(Pin !º of IC301) of the HI microprocessor.

When C609 of the ST board is charged, the voltage is divided, and input to the comparator (Pin 1 of IC602). The

earlier mentioned 3.2V will be input to Pin 3 of IC602 to compare the voltage.

When the flash voltage becomes above 300V, Pin 4 of IC602 becomes L from H. This L output is then detected by the

XCHGEND terminal (Pin 3 of IC301) of the HI microprocessor and charging is stopped.

When charging completes, the flash mark will be displayed on the LCD.

Q303 and Q301 of the HV board are turned ON by the H output from the STBOON terminal (Pin &∞ of IC301) of the

HI microprocessor, and 5V is output to the ST board and Q315.

When the shutter is pressed, the storobo emission signal is output from the STBOTRG terminal (Pin !¶ of IC301) of the

camera microprocessor.

This is the 10 µs, 3Vp-p H single signal.
This STBOTRG signal turn ON Q316 and Q315 of the HV board, and the thyristor (D604) of the ST board is turned

ON. As a result, a parallel resonance circuit is formed with T602, etc., and a 20 times greater voltage output (about 5000V)
is output to the emission tube.

During storobo emission, Q608 will be ON so that a current about 150A flows instantaneously.