Md Test Mode & Adjustments - Yamaha GX-900 Service Manual

MD TEST MODE & ADJUSTMENT
Preparation before Adjustment
Test disc
Type Test disc
High reflecting disc TDYS1 (SONY) [for reproduction] (P/No. TX945850)
Low reflecting disc Commercially available mini disc for recording
Low reflecting disc MMD-318 [for pre-adjustment] (P/No. AAX04890)
MD TEST MODE
1. How to set to the test mode
1) In the STANDBY mode, press the STANDBY/ON button while pressing the RANDOM button and the PLAY/
PAUSE(CD) button.
"<Key Operate" on display ............................................................... SYSTEM TEST MODE
2) Select the MD TEST MODE by the section name, pressing the wINPUT (up) or qINPUT (down) button.
3) Pressing the MUSIC button will shift the mode to the MD test mode.
Version of microprocessor on display (about 1 second)
t s m 1 3 0 1 e 0 2
"EJECT" on display
4) Load either a disc for reproduction or a disc for recording.
"AUT YOBI" on display
This completes setting to the test mode.
2. How to set to each mode
Every time the r(MD) button is pressed, the mode changes. (For operation of each mode, refer to the section describ-
ing each mode.)
->AUTO pre-adjustment -> AUTO adjustment -> RESULT preparation -> RESULT -> MANUAL pre-adjustment ->
MANUAL adjustment -> EEPROM setting
Caution) The AUTO pre-adjustment and AUTO adjustment modes are used for adjustment during servicing. Other modes
are used when checking the specific measured values and adjusted values or when changing the set value and the
adjusted value. Note that use of other modes will rewrite RAM and EEPROM.
3. How to cancel test mode
1) Finish the AUTO pre-adjustment and AUTO adjustment. ( "COMPLETE" appears on the display)
2) Press the a(MD) button. ( "TEST END" appears on the display)
3) Eject the disc by pressing the EJECT button.
4) Turn off the power.
When using a new combination of a mechanical pickup and an MD P.C.B. after a repair or for some other
reason, make sure to set to the TEST mode and perform AUTO pre-adjustment and AUTO adjustment accord-
ing to the following procedure.
1) Set to the TEST mode and perform AUTO pre-adjustment and AUTO adjustment.
2) Cancel the TEST mode by pressing the a(MD) button. (Writing into EEPROM starts from here.)
3) Eject the disc by pressing the EJECT button.
4) Turn off the power.
Version of EEPROM protect data (from 01)
Version of microprocessor ROM (from 01)
Extension cable (see connection diagram on page 35.)
Type
1. Extension P.C.B. for servicing
2. 2-pin extension connector for servicing
3. 6-pin extension connector for servicing
4. 5-pin flat cable for servicing
5. 28-pin flat cable for servicing
GX-900
Part No.
TX946230
TX946200
TX946210
TX946190
TX946220
30