Sony RMT-D145E Service Manual Download

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SAFETY-RELATED COMPONENT WARNING!!

COMPONENTS IDENTIFIED BY MARK

OR DOTTED LINE WITH

MARK

ON THE SCHEMATIC DIAGRAMS AND IN THE PARTS

LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE
COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS
APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS
PUBLISHED BY SONY.

Check the area of your repair for unsoldered or poorly-soldered
connections. Check the entire board surface for solder splashes
and bridges.

Check the interboard wiring to ensure that no wires are
"pinched" or contact high-wattage resistors.

Look for unauthorized replacement parts, particularly
transistors, that were installed during a previous repair. Point
them out to the customer and recommend their replacement.

Look for parts which, through functioning, show obvious signs
of deterioration. Point them out to the customer and
recommend their replacement.

Check the line cord for cracks and abrasian. Recommend the
replacement of any such line cord to the customer.

Check the B+ voltage to see it is at the values specified.

Flexible Circuit Board Repairing

• Keep the temperature of the soldering iron around 270°C

during repairing.

• Do not touch the soldering iron on the same conductor of the

circuit board (within 3 times).

• Be careful not to apply force on the conductor when soldering

or unsoldering.

SAFETY CHECK-OUT

After correcting the original service problem, perform the following

safety checks before releasing the set to the customer.

LEAKAGE TEST

The AC leakage from any exposed metal part to earth ground

and from all exposed metal parts to any exposed metal part having a
return to chassis, must not exceed 0.5 mA (500 microamperes).
Leakage current can be measured by any one of three methods.

1. A commercial leakage tester, such as the Simpson 229 or RCA

WT-540A. Follow the manufacturers' instructions to use these
instruments.

2. A battery-operated AC milliammeter. The Data Precision 245

digital multimeter is suitable for this job.

3. Measuring the voltage drop across a resistor by means of a VOM

or battery-operated AC voltmeter. The “limit” indication is
0.75V, so analog meters must have an accurate low-voltage scale.
The Simpson 250 and Sanwa SH-63Trd are examples of a
passive VOM that is suitable. Nearly all battery operated digital
multimeters that have a 2V AC range are suitable. (See Fig. A)

Fig. A.

Using an AC voltmeter to check AC leakage.

1.5 k

Ω

0.15 µF

AC
voltmeter
(0.75 V)

To Exposed Metal
Parts on Set

Earth Ground

WARNING!!

WHEN SERVICING, DO NOT APPROACH THE LASER EXIT WITH
THE EYE TOO CLOSELY. IN CASE IT IS NECESSARY TO CONFIRM
LASER BEAM EMISSION, BE SURE TO OBSERVE FROM A
DISTANCE OF MORE THAN 25 cm FROM THE SURFACE OF THE
OBJECTIVE LENS ON THE OPTICAL PICK-UP BLOCK.

CAUTION:

The use of optical instrument with this product will increase eye
hazard.

Unleaded solder

Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with
the lead free mark due to their particular size.)

: LEAD FREE MARK

Unleaded solder has the following characteristics.
• Unleaded solder melts at a temperature about 40°C higher than

ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
about 350°C.
Caution: The printed pattern (copper foil) may peel away if the
heated tip is applied for too long, so be careful!

• Strong viscosity

Unleaded solder is more viscous (sticky, less prone to flow) than
ordinary solder so use caution not to let solder bridges occur such
as on IC pins, etc.

• Usable with ordinary solder

It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.

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