Skip to content

Repair: Nanao MS9 monitor

The successor to the Nanao MS8, fitted in more recent Sega candy cabs (New Astro City, Blast City, Net City…). Same repair philosophy: recap first.

Identification

Field Value
Manufacturer Nanao (EIZO)
Type Colour CRT monitor chassis
Sizes MS9-29 (29") and variants
Frequencies 15 / 24 kHz; tri-sync variants (15/24/31 kHz) exist
Cabinets New Astro City, Blast City, Net City…

Differences from the MS8

  • A more recent chassis (New Astro City 1995 and later).
  • Some variants handle 31 kHz (VGA/Naomi) — to confirm per the exact sub-model. The true Nanao 15/24/31 kHz tri-sync is the MS2930–MS2933 series (New Net City, Naomi Universal).
  • Identical repair procedure: see the Nanao MS8 page for the detail (tube discharge, recap, reflow, adjustments).

Level & risks
Difficulty Intermediate → Advanced
Risks CRT high voltage (lethal), fragile joints
Time Recap: 2-4 h

High voltage — discharge the tube

Like any CRT: high voltage retained even unplugged. Discharge the anode before work. Don't work alone if untrained.

Common faults

Identical to the MS8: image that shrinks/shakes, no image, focus, washed-out colours, intermittent cut-outs (cold joints), deflection folds. → Detailed table on the Nanao MS8 page.

Recap

The main repair. Identical procedure to the MS8: see the MS8 recap section.

Capacitor list — MS-9 ✅

Source: Arcade Otaku (reference listing). 40 capacitors, including a bipolar C411 (2.2 µF/50 V). The C911 1000 µF/200 V filter is separate (mentioned by seller kits, not counted here). Shopping list:

Value Voltage Qty
1 µF 50 V 3
2.2 µF 50 V 4 (incl. 1 bipolar, C411)
10 µF 16 V 1
10 µF 35 V 1
10 µF 50 V 3
10 µF 250 V 2
22 µF 50 V 5
47 µF 16 V 5
47 µF 160 V 1
100 µF 10 V 1
100 µF 16 V 1
100 µF 35 V 4
100 µF 160 V 1
180 µF 25 V 1
180 µF 100 V 1
220 µF 100 V 1
470 µF 16 V 2
680 µF 10 V 1
680 µF 35 V 1
1000 µF 35 V 1

Seller discrepancies

Some seller kits list slightly different values on a few references (e.g. C406, C562, C955) and a total around 42. Cross-check with your board / the schematic if in doubt.

Per-reference list (40) — expand

NB = neck board, RB = remote board, BP = bipolar.

Ref µF V Ref µF V
C102 1 50 C455 10 50
C107 22 50 C456 10 50
C201 47 16 C457 10 50
C202 47 16 C458 22 50
C203 47 16 C459 22 50
C211 2.2 50 C503 100 35
C212 2.2 50 C513 10 250
C213 2.2 50 C515 100 160
C220 470 16 C554 1 50
C221 100 16 C556 1 50
C222 22 50 C561 47 16
C280 (RB) 10 16 C562 100 10
C332 (NB) 10 250 C951 180 100
C402 470 16 C952 220 100
C406 1000 35 C953 47 160
C407 100 35 C954 680 35
C408 100 35 C955 180 25
C409 100 35 C956 680 10
C411 (BP) 2.2 50 C957 10 35
C451 22 50 C958 47 16

→ Alternative kits: Console5 · arcademonitor.com

Sources & attribution

Review & corrections

How this space is used

Spotted a wrong value, an outdated procedure, a chip reference that does not match your board? Say so here, with what you observed (model, board revision, serial number, measurement). Every report is cross-checked against a source before anything changes — an unverifiable correction is published as “reported by …, not cross-checked” rather than silently applied.

Reading is open to everyone; posting requires signing in with Discord. Reports from the wiki's declared reviewers are handled first; anyone else's are read too, but go through a human before anything is changed.