Table Of Contents; Verify That The Protector Is Operated And D918 Illuminates Red; Verify That The Protector Is Not Released And D918 Remains Red; Even When The Short Is Removed - Sony XM-GTX6020 Service Manual

XM-GTX6020/GTX6022
PROTECTOR OPERATION CHECK
Thermal Protect
1. Short across TH901 with the power on.
2. Verify that the protector is operated and D918 illuminates
green. When input the signal and verify that there is no output
on the SP-OUT even when the volume is increased.
3. Verify that the protector is released and there is an output on
the SP-OUT when the short is removed.
4. Likewise, perform items 1 to 3 for TH902 and TH903.
Over Current Protect
1. Short between the positive and negative sides of the speaker
output terminals CN903 (1/2) with the power on.
2. Verify that the protector is operated and D918 illuminates red.
3. Verify that the protector is not released and D918 remains red
even when the short is removed.
4. Verify that the protector is released and D918 illuminates
green when the power is turned off and then on again.
Offset Protect
1. Short between the +12V terminal of CN903 (2/2) and the
(BTL) + or (BTL) - of the speaker output terminal CN903
(1/2).
(Short between +12V terminal and (BTL) + and between +12V
terminal and (BTL) -.)

2. Verify that the protector is operated and D918 illuminates red.

3. Verify that the protector is not released and D918 remains red

even when the short is removed.

4. Verify that the protector is released and D918 illuminates

green when the power is turned off and then on again.
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 fl ow)
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.
NOTES ON CHIP COMPONENT REPLACEMENT
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
2

TABLE OF CONTENTS

1. GENERAL
Connections ....................................................................
2. DISASSEMBLY
2-1. Bottom Plate ...................................................................
2-2. MAIN Board Section ......................................................
2-3. MAIN Board ...................................................................
3. DIAGRAMS
3-1. Block Diagram ................................................................
3-2. Printed Wiring Board ...................................................... 11
3-3. Schematic Diagram ......................................................... 12
4. EXPLODED VIEWS
4-1. Main Heat Sink Section .................................................. 13
4-2. MAIN Board Section ...................................................... 14
5. ELECTRICAL PARTS LIST
SAFETY-RELATED COMPONENT WARNING!
COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED LINE
WITH MARK 0 ON THE SCHEMATIC DIAGRAMS AND IN
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS
WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS
MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.
3
6
7
7
9
.............................. 15
WITH SONY PARTS