Bachmann GRPT140 Service Manual

GRPT140

SERVICE MANUAL

Index
2
Keyboard Assembly & Block Diagram
3 Autotest & Keyboard Calibration Procedures
4 Power Amplifier & Supply, Controls & Phones, Crossover, Aux & Midi I/O Boards Schematic Diagrams
5
CPU & Sound Generator Board Schematic Diagram
6
Keyboard Interface & Left Optical Contact Boards Schematic Diagrams
7
Centre & Right Optical Contact Boards Schematic Diagrams
8
Spare Part List
Warnings
Address
CODE: 270227
Notice
Service must be carried out by qualified personnel only.Any tampering carried out by unqualified personnel during the guarantee period
will forfeit the right to guarantee.
For a correct operation of the instrument, after having switched off, be careful to wait at least 3 seconds before switching on again.
To improve the device's specifications, the schematic diagrams may be subject to change without prior notice.
All components marked by this symbol have special safety characteristics, when replacing any of these components use only
manufacturer's specified parts.
The (µ) micro symbol of capacitance value is substituted by U.
The (Ω) omega symbol of resistance value is substituted by E.
The electrolytic capacitors are 25Vdc rated voltage unless otherwise specified.
All resistors are 1/8Ω unless otherwise specified.
All switches shown in the "OFF" position. All DC voltages measured to ground with a voltmeter 20KOhm/V.
Soldering point. Supply voltage.
Male connector. Test point.
Female connector. Flag joined with one or more flags
M/F faston connector. with the same signal name inscribed.
ATTENTION
Observe precautions when handling electrostatic sensitive devices.
GENERALMUSIC S.p.A. Sales Division: 47842 S.Giovanni in Marignano (RN) ITALY - Via delle Rose, 12 - tel. 0541/959511 - fax 0541/957404
GENERALMUSIC on the NET: http://www.generalmusic.com
Logic supply ground.
Analog supply ground.
Chassis ground.
Earth ground.
1