Panasonic CF-2700 Service Manual

The Service Manual: Personal Computer CF-2700 is Matsushita Electric Trading Co.'s service manual for the export Panasonic CF-2700 MSX computer, order number IED84113035C2, copyright Matsushita Electric Industrial Co., Ltd. 1984. The copy on the wiki is a 65-page PDF scanned by Hans Otten (HansO) from an original supplied by Bas Kornalijnslijper (MCWF), and comes from the MSX Archive. It covers the machine sold for 220 V, 50 Hz mains; the U.K. version runs on 240 V, 50 Hz.

The specification on page 1 gives a Z-80A processor, 32 KB of ROM holding MSX-BASIC, 64 KB of main RAM, 16 KB of video RAM, a TMS 9929A video controller, an AY-3-8910A sound chip, 73 keys, an FSK cassette interface at 1200 or 2400 baud, two cartridge slots, a 14-pin printer port, two 9-pin general ports, a size of 436 × 245 × 90 mm, a weight of about 3.6 kg and a power consumption of 28 W.

Contents

The manual's own contents list, with its printed page numbers:

Section	Printed page	PDF page
Specifications	1	1
Location of Controls and Components	3	3
Memory Map; I/O Map	5	5
General for Peripheral Circuit (including the cassette interface and the power supply circuit on pages 18 and 19)	7	7
Display Screen, Character Codes	20	18
Self Test	21	19
Block Diagram	33	31
Disassembly Instructions	34	32
Adjustment	39	37
Connector Pin Connection	40	38
Wiring Connection Diagram	42	40
Schematic Diagram (Main Board)	43	41
Printed Circuit Board (Main Board)	47	45
Schematic Diagram and Printed Circuit Board (Power Source)	49	47
Schematic Diagram (Video Board)	50	48
Printed Circuit Board (Video Board)	51	49
Printed Circuit Board (Keyboard)	52	50
IC Block Diagram	53	51
Parts Location; Parts Location (Keyboard)	62, 63	60, 61
Packing Instruction; Replacement Parts List	64 to 67	62 to 65

There are no printed pages 16 and 17; the scanner's note on PDF page 15 says the original has none. From printed page 18 onwards the PDF page number is two lower than the printed one.

The sections a repairer will use most:

• Power supply circuit (printed pages 18 and 19). A "dropper" supply gives +5 V, −5 V, +12 V and −12 V. The +5 V regulator is discrete: Q1 (2SA1061P) as the series pass transistor, Q7 (2SC1318-Q) driving it, and Q8 and Q2 (2SA722-S) as the error amplifier, with VR1 setting the output. +12 V comes from an AN7812R (IC1) and −12 V from an AN7912T (IC2). A PSW line switches +5 V and +12 V off through Q9 (2SC1685-Q) and pin 4 of IC1 when it is not held at ground; −5 V and −12 V stay on. R38 and C38 delay the rise of +5 V and +12 V at switch-on. The diagram on page 19 gives the value and voltage rating of each electrolytic capacitor in the supply.
• Disassembly (from printed page 34): the top cabinet, keyboard and main board are on pages 34 and 35, with screw sizes and the connectors to unplug.
• Adjustment (printed page 39): the RF channel trimmer for UHF channels 35 to 37, the +5 V supply (VR1, for 4.97 to 5.03 V at pin 45 of CN7 with pin 41 as ground), and the colour clock (trimmer CT201 on the video board, for 4.43361875 MHz ±3 Hz at pin 9 of IC203).
• Self test (printed pages 21 to 32): a twelve-part test run from Panasonic's test cartridge, part number DFWV95C0001, with an MSX printer, a joystick, a television and a cassette recorder.
• Replacement parts list (printed pages 64 to 67): every part on the main board, power source board, video board and keyboard, with Panasonic part numbers.

What this manual does not contain

• It covers the export CF-2700 only. The Japanese National CF-2700 has 32 KB of RAM where the export model has 64 KB, and a photograph of a Japanese machine shows its power supply on a separate board with 100-series designators, where the export model in this manual has its regulators on the main board. The CF-1200 and the FS-1300, which share the case, are not covered.
• The power source schematic on printed page 49 is a low-resolution image and hard to read. The same circuit is legible on printed page 19.
• Printed page 45 of the main board schematic appears twice in the scan (PDF pages 43 and 44 are the same image), and printed page 46, the last sheet of the main board schematic, is missing.
• There is no fault-finding section. The self test needs the test cartridge, which is not part of the scan.
• The text and the drawings disagree in a few places:
  • The circuit description on page 18 names C7 as the +5 V smoothing capacitor. The diagram on page 19 shows C11 (6800 µF, 16 V) in that position and C7 (330 µF, 16 V) on the +12 V output, and the parts list agrees with the diagram.
  • The diagram labels the 16 V, 100 µF capacitor on the −5 V line C14, but the parts list gives C14 as a 0.1 µF film capacitor.
  • In the parts list, C20, C52 and C55 (ECSF1AE225) are described as 22 µF and C28 (ECSF1EE226) as 220 µF. In the usual three-digit code those part numbers mean 2.2 µF and 22 µF. Read the part on the board before ordering.
  • The memory description on page 8 says the 64 KB of main memory is made of "eight 16 K x 8-bit DRAMs". The parts list (DA4164ANL12M) and the schematic on page 44 (MSK4164ANL-12) give IC11 to IC18 as 4164-type DRAMs.
  • The adjustment drawing labels the second cartridge connector CN8; the parts list and the wiring diagram give the slots as CN6 and CN7 and use CN8 for a keyboard connector.

Pages that cite this document

• National FS-1300: the shared case and the relationship to the export CF-2700.
• National FS-1300 General Maintenance: disassembly, supply rails and slot pins.
• National FS-1300 Troubleshooting Guide: power supply fault-finding.
• National FS-1300 Capacitor Replacement Guide: the export CF-2700 electrolytic list.
• National CF-3000 Troubleshooting Guide: the MSX cartridge slot supply pins.
• Panasonic CF-2700: specification, boards, supply and slot switches.
• Panasonic CF-2700 General Maintenance: disassembly, rail checks and the VR1, CT201 and RF adjustments.
• Panasonic CF-2700 Troubleshooting Guide: rail patterns, PSW, clocks, pinouts and port faults.
• Panasonic CF-2700 Capacitor Replacement Guide: the electrolytic list from the parts list and the supply diagram.

References

Download: Panasonic CF-2700 Service Manual IED84113035C2.pdf