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TC Electronic A/S
M5000 Service manual
page 16
Circuit descriptions:
The M5000/X Mainframe consist of; power supply, CPU board, floppy disc drive, bus board and front board.
Power Supply:
The power supply in Mainframe Type M5000F10 (black chassis) has a toroidal transformer. This transformer has 2 secondary windings of 20 - 0 - 20V.
These voltages are regulated on the power supply board to +/-20VDC, and a switch mode circuit pr5.1VDC and -5VDC.
The frequency in the switch mode circuit can be controlled by the sample frequency via IC3, however - IC3 is removed on some boards while this control facility is unnecessary,.
The power supply in Mainframe Type M5000F20 (gold chassis) is a switch mode power supply with automatic setting for ac input. It pr/-18VDC and +/-5VDC.
This service manual does not contain schematics for the power supply module in Mainframe type M5000F20, because any attempt to repair the power supply module must be completed with some
safety tests such as high voltage and EMC tests. Hence, it is strongly recommended that the entire power supply module is replaced in case of malfunction.
CPU board, ver. M5000-x:
CPU board has following sections; CPU section, Jeida connector, Memeory section, Bus interface, Floppy disk interface, SMPTE/Midi/Pedal interface.
CPU section consist of the CPU, IC5 and the address latches IC6 + 7. IC2 and IC10 (PAL) makes all the Chip Select signals. IC11 and IC8 are latches for control signals.
The jeida connector is connected to the data and address signals. IC21 is an interface for incomming control signals. IC18 (PAL) is interface for outgoing control signals.
The memory section has an multiplexer (IC28+29+30) for the Dynamic RAM (IC24+25+26+27). The SRAM (IC22) is working memory for the CPU. The SRAM has battery back up. The two
EPROMs (IC31+32) contain the BIOS software. The Flash (IC23) contains the application software. A DC/DC converter (IC33) produces burning voltage for the Flash at time of loading application
software. The EEPROM (IC4) contain serial no. information. IC4 can only be replaced at TC Electronic main service center!
The Bus Interface has interface circuits (IC37+38+39+40+41) for control -, data - and address signals. Located here is also the circuit (IC15+X1+X2) which generate the sample rates. Reset circuit is IC3.
Floppy disk Interface simply consist of IC35 and X3.
SMPTE/Midi/Pedal interface: IC36 receives the SMPTE input signals. IC13 receives Midi in signals. IC 1A+B sends Midi signals to Midi thru and Midi out. IC12 receives Remote signals. IC1C sends
Remote signals. IC 45 is always disabled! Pedal In signals goes via R13 directly to the CPU.
Floppy disc drive:
This service manual does not contain schematics for the floppy disc drive. Hence, it is recommended that the entire floppy disc drive is replaced in case of malfunction.
Bus board:
The components on the bus board are mainly connectors, pull up/down resistors and decoupling capacitors. R3+R5+C18 are for ground lift.
Front board for M5000:
