Adjusting The Electrical Circuits; Before Starting The Electric Circuit Adjustment - Sharp VL-PD3U Service Manual

VL-PD3U
10. ADJUSTING THE ELECTRICAL CIRCUITS
Before starting the electric circuit adjustment
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The adjustment methods described herein are used, in most cases, when the expendable mechanical parts, including
the video head, have been replaced, at which time the electrical circuits need to be readjusted. Before adjusting the
electrical circuits, make sure that the mechanism works properly (i.e., the mechanism is properly adjusted). lncase of
the occurrence of any problem to the electrical circuits, be sure to use the specified measuring instruments to locate
the area to which the problem is occurring, and then take the necessary action, including repair, replacement or
adjustment, exactly as instructed in the electrical adjustment methods that will follow.
Do not attempt to make adjustments without using the proper measuring instruments.
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This machine is configured so that the electrical circuits inside its PWB unit are composed, for the most part, of high-
density, small surface-mounted component parts for downsized machine body.
To perform repair service or parts replacement, do so using a soldering iron, but in as short a time as possible; this is
because surface-mounted component parts are generally so small in size and susceptible to heat, as compared with
the large discrete parts used in TV sets, desk-top video decks, etc., that attempting to heat their electrodes for a longer
time than is necessary with a soldering iron may result in their becoming defective.
This applies particularly when replacing the laminated chip capacitors.
For this purpose, ceramic soldering irons with a temperature regulator are recommended (iron tip temperature 250°C
and soldering time 5 seconds or shorter).
The VL-PD3U and other models that follow are newly equipped with the digital interface function. The Digital Interface
IEEE1394 Standard stipulates that each set with the digital interface function be given its specific ID number. The ID
number is written on the E*PROM of the set while it is manufactured. If the E*PROM alone or the PWB having this E*PROM
on it has been replaced for repair purpose, it is necessary to write a new ID number again. (Note that any replacement
part does not have an ID number yet.)
Accordingly, the repair engineer must obtain the new ID number.
Head amplifier PWB
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If the IC302 (E*PROM) or the head amplifier PWB has been replaced, it is necessary to write a new ID number. (Note that
any replacement part does not have an ID number yet.)
Obtain a new ID number from the service department of sales company. Take the following steps to write the ID number
on the E*PROM.
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Manual for obtaining and handlig IEEE1394 ID number
1. Access the intranet URL for the number below.
URL: http://www.rog.kami.sharp.co.jp/quics/e_index.html
2. Now enter User ID and Password, then clickI .
*ID and Password should be same as for "PARTS PEICE LIST".
Please enter User ID and Password.
. UserlD
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Password
The VL-PD3U and other models that follow are newly equipped with the digital interface funcion.
The Digital Interface IEEE1394 Standard stipulates that each set with the digital interface funcion be given its
specific ID number.
The ID number is written on the E*PROM of the set while it is menufactured.
If the E*PROM alone or the PWB having this E*PROM on it has been replaced for repair purpose, it is necessary
to write a new ID number again.
(Note that any replacement part code does not have an ID number yet.)
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