SONY HKPF-525AV
Service Manual

Section 1 Service Overview
1-1. Circuit Description
RC-80/80A board The HD SDI signal that is input from the DIF-96/96A board is converted to the 20-bit parallel data of 74 MHz by IC202. HD-H (horizontal sync signal) and HD-F (frame sync signal) are extracted by the format decoder IC204. The HD digital signal is converted to the 10-bit parallel data of 27 MHz by down-converter IC302 and is output as the SD component digital signal. The SD digital signal passes through the frame memories (IC400, IC401, IC403) and the SAV/EAV are added to the SD digital signal at the format encoders IC609 and IC610. The EDH signal is also added SD digital signal by IC700 and IC701. The SD digital signal is converted to the SD component serial digital (SDI) signal by IC702 and IC703 and is output via DIF-96/96A. The RC-80/80A board contains the power circuit consisting of the four switching regulators: +3.3 V, +2.5 V, +1.2 V and _2V. It also contains the series regulators regulating +2.5 V power to +1.8 V power. The RC-80/80A board contains also the detection circuits to detect automatically the number of lines (1035/1080) in video area of the picture. The RC80/80A board stores the statuses such as number of lines in video area immediately before turning off the main power and the field frequency in EEPROM. In addition, the RC-80A board for the HKPF-525AV processes the audio data. The audio data is extracted by IC204 and the digital audio signal that is supplied by the multiplexing in the HD SDI signal is separated. The digital audio signal that is thus separated is written in the FIFO (IC402) and is read while matching the timing with the delay time of the video signal. The digital audio signal that is read with appropriate delay is converted to the parallel data by IC603 and is multiplex with the video signal at IC609, IC610. DIF-96/96A board The DIF-96/96A board has the HD SDI signal input connector (one channel), the SD SYNC signal input connector (one channel) and the REMOTE IN connector. It also has the SD component SDI signal output connector (four channels) and a loop-through output (one channel) of the SD SYNC signal input. It also has the cable equalizer and the clock recovery circuit of the HD SDI signal.
HKPF-525AV/525V MM

1-2. Optional Fixtures
Description P/N Remarks To extend RC-80/80A board To extract IC900/RC-80/80A board (Usable for PLCC IC with pins 20 to 124) Extension board J-6185-960-A EX-331 IC extractor J-6035-070-A

1-3. Circuit Protection Device
The RC-80/80A board is equipped with two positive thermistors THP1 and THP2 for +5 V and _5 V respectively. This device limits a current by steeply increasing the inner resistance when it rises to a certain temperature due to overcurrent or high ambient temperature. The device being activated, the indicator (D1, D3) beside it will go out at the same time. If activated, turn off the power and check the unit. After the cause is eliminated and the device cools off, turn on the power again. If there is no trouble, the unit will operate normally.

1-4. Note on Replacement of Electrical Parts
The RC-80/80A and DIF-96/96A boards are equipped with a high-frequency circuit (1.5 GHz) in the shielding case on each board. So every electrical part contained in the shielding case can not be replaced. If the high-frequency circuit in the RC-80/80A board fails, please order the HKPF-525AV/525V through the sales route for replacement. If that in the DIF-96/96A board fails, replace the DIF-96/96A board itself.

1-1 (E)