Akai GX-270 Reference Manual

www.reeltoreel.nl / Philip van der Matten / ver 1.0 / 20 dec 2023 / page 1 of 5

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Quick Reference Guide to AKAI GX-270D:

Page:

2 location of the circuit boards, action list

3 component layout of the rec & pb boards

4 component layout of the power & servo boards

5 component list per PCB

6 etc

www.reeltoreel.nl / Philip van der Matten / ver 1.0 / 20 dec 2023 / page 2 of 5

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Location of the internal printed circuit boards:

system control pcb (2221)

peak level pcb (5202)

LR

backside

playback amp pcb (5017)osc & rec amp pcb (5016)

servo control pcb(2036)

power supply pcb (2222)

Common problems, service, revise, overhaul, refurbish actions etc:

□ Replace all caps on REC & PB boards, see pg. 3 & 4
□ Replace all transistors on REC & PB boards with KSC1845, see pg. 3 & 4
□ clean both speed switches
□ replace all sparkkillers on power supply pcb, and 1 between reels on front
□ TIP48 transistor replace with TIP50
□ (replace 4 diodes on servoboard with FR207 (1000V / 2A) )
□ (replace 8 diodes on power supply board with FR207 (1000V / 2A) )
□ motor caps 5µF/150V capstanmotor + 2x 4µF/250V spoolmotor. could be replaced if necessary
□ big 330µF/160V high ripple cap could be replaced

All specs are for the CEE 220/240V version

TIP48

330µF/160V

5µF/150V

capstan

4µF 2x

spool motors

www.reeltoreel.nl / Philip van der Matten / ver 1.0 / 20 dec 2023 / page 3 of 5

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osc & rec amp pcb (5016)

47/50 47 100/25 47 47 47 100/25 1/25 100/25 47 47 47 100 47 47/50

rightleft

Component side

10/16 10/16 10/16 10/1610/16 10/16 10/16 10/16

10/25 10/1610/16 10/25

playback amp pcb (5017)

10/16 47 47 47 47 47 100/6,3 100/6,3 47 47 47 47 47 10/16

output

Component side

1/25 10/16

C1845
x12

10/16 1/25 10/16 10/16

10/1610/16

4,7/25 4,7/25

!

!

10/1610/16

C1845
x12

www.reeltoreel.nl / Philip van der Matten / ver 1.0 / 20 dec 2023 / page 4 of 5

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button

relais

10/25 1/25 1/25

33/25 33/25

33/25 3,3/25

1/25 100/16 1/25

10/25

system control pcb (2221)

power supply pcb (2222)

0,47µF/250V

MP/film/foil

(2x)

220/25

470/50 220/35

Sparkkiller

0,1µF + 120Ω

(7x)

www.reeltoreel.nl / Philip van der Matten / ver 1.0 / 20 dec 2023 / page 5 of 5

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cap µF/volt # transistor/semi/diodes #

power supply pcb 470/50 1 replace all 10D4 FR207→ 4x

220/35 2 replace all 10D5 FR207→ 4x
0,47/250 2 axial, film
0,1+120hm 7 sparkkiller

­system ctrl pcb 1/25 4

10/25 2
100/16 1
3,3/25 1
33/25 3

­servo pcb 0,47 BiPolar 1 replace all 10D2 FR207→ 4x

1/25 1
10/16 1
100/25 1
3,3/25 2
47/50 1

­peak level pcb 0,47/25 2

10/25 2
3,3/25 1
4,7/25 2
47/25 1

­playback pcb 1/25 2 replace all trans. c1845→ 12x

10/16 8
100/6,3 2
4,7/25 2
47/25 8

­rec + osc pcb 1/25 1 replace all trans. c1845 → 12x

10/25 12
100/25 4
47/25 10

[some caps are combined at a higher voltage for convenience]

total 87

Component list per PCB