HCD-GTR333, HCD-GTR555, HCD-GTR777, HCD-GTR888, MHC-GTR333, MHC-GTR555, MHC-GTR777, MHC-GTR888 - Sony Audio Service Manual (repair manual). Page 4

The laser diode in the optical pick-up block may suffer electro-
static break-down because of the potential difference generated by 
the charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic break-down and also 
use the procedure in the printed matter which is included in the 
repair parts.
The fl exible board is easily damaged and should be handled with 
care.

NOTE  OF  REPLACING  2CH/3CH/4CH  DAMP  BOARD
Thermal Sheet (P/N: 4-265-384-01) which is attached to heat sink 
on DAMP board may deform by contact of IC long time. When 
you replace DAMP board, please remove the original sheet from 
heat sink and attach new one.

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)

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.

NOTE  OF  REPLACING  THE  IC102  AND  IC4605  ON  
THE  DMB21  BOARD
IC102 and IC4605 on the DMB21 board cannot exchange with 
single. When these parts on the DMB21 board are damaged, ex-
change the entire mounted board.

RELEASING  THE  DISC  TRAY  LOCK
The disc tray lock function for the antitheft of an demonstration 
disc in the store is equipped.

Releasing Procedure:
1. Press 

[I/

1

 STANDBY] button to turn the power on.

2.  Press the [CD/DISC SKIP] button to select CD function.
3.  While pressing the [TV] button, press the [

Z

 OPEN/CLOSE] 

button for more 5 seconds).

4.  The message “UNLOCKED” is displayed and the disc tray is 

unlocked.

Note: When 

“

LOCKED

”

 is displayed, the slot lock is not released by 

turning power on/off with the

 [I/

1

 STANDBY]

 button.

HCD-GTR333: E2, E51, AR /
HCD-GTR555: AR

4-265-400-0[]

HCD-GTR333: MX

4-265-400-2[]

HCD-GTR555: E2, E51

4-265-400-5[]

HCD-GTR555: MX

4-265-400-7[]

HCD-GTR777, GTR888: E2, E51, AR

4-265-401-0[]

HCD-GTR777, GTR888: MX

4-265-401-2[]

NOTES  ON  LASER DIODE  EMISSION  CHECK
The laser beam on this model is concentrated so as to be focused 
on the disc refl ective surface by the objective lens in the optical 
pickup block. Therefore, when checking the laser diode emission, 
observe from more than 30 cm away from the objective lens.

Note: Refer to supplement-1 for the printed wiring board, 

schematic diagram and electrical parts list of MAIN board 
(Suffi x-13 and Suffi x-21, 41, 51).