RED V-Raptor / Milo - Universal Sync Box Failure and Misconnection Risk¶
Summary¶
A Milo/V-Raptor setup showed a green sync light on the Universal Sync Box but no sync pulse reaching Flair. The final diagnosis was Universal Sync Box failure, with two possible causes: an internal ribbon/connector fault, or damage caused by routing sync through the Trigger Box while its camera emulator was enabled.
Symptoms¶
- Universal Sync Box green LED shows incoming sync.
- Camera run/stop still works.
- Flair test window does not see sync pulse.
- No sync reaches RT14/Cinebot/Milo path.
- Issue persists after camera-side settings appear correct.
WhatsApp Excerpts¶
| Timestamp | User | Evidence |
|---|---|---|
| 2026-03-27 02:43 | Jeremy Andrews | Milo had no sync pulse from RED V-Raptor; tried Universal Sync Box through roll-axis D-type; box showed power and green sync light. |
| 2026-03-27 02:57 | Timothy Smith | Described expected wiring chain: V-Raptor R/S and sync cables to Universal Sync Box, through roll slip-ring D-type camera accessories port, Milo umbilical to camera accessories port, trigger box ribbon cable to RT14; suggested spare ribbon cable. |
| 2026-03-27 04:28 | Arturo | Asked whether RED sync cable to Universal Sync Box was used. |
| 2026-03-27 07:17 | Jeremy Andrews | Confirmed Universal Sync Box failure; multiple issues. |
| 2026-03-27 07:22 | Jeremy Andrews | Cam accessories cable had been plugged into the lower trigger-box plug rather than sync socket on ribbon cable, likely blowing the sync box. |
| 2026-03-27 07:30 | Jeremy Andrews | Listed two causes: internal ribbon disconnect, or sync through trigger box while sync emulator is on blowing the Universal Sync Box. |
Community Solutions¶
[CONFIRMED] Swap In A Known-Good Universal Sync Box¶
If green sync LED is present but no output reaches Flair, test with a spare Universal Sync Box. In the reported case, the box itself was faulty.
Confidence: 0.9
[LIKELY] Inspect Internal Ribbon / Connector Path¶
An internal ribbon disconnect or connector-pin issue can allow the box to show input activity while failing to pass sync onward.
Confidence: 0.74
[DANGEROUS] Do Not Route Sync Through Trigger Box With Camera Emulator Enabled¶
If a system routes camera sync to RT14, connecting sync through the Trigger Box while the trigger-box camera emulator is on may put additional voltage on the circuit and damage the Universal Sync Box.
Confidence: 0.86
Related Discussion Evidence¶
No image/video attachment in the final diagnosis, but discussion references Milo cabling and Universal Sync Box routing.
Official Documentation References¶
- Flair Virtual Production Sync Box QSG — p.7: default 50 Hz data output and supported sync/data modes
- Flair Virtual Production Sync Box QSG — p.9: No Sync / send-on-data behaviour
- Camera Sync and Trigger V2 — RED camera sync/trigger cable matrix
- Trigger Box QSG — printed p.2: ribbon cable SYNC / BLOOP / TRIGGER routing
- Trigger Box QSG — printed p.10: using the Sync input from a camera
- Trigger Box QSG — printed p.12: sync and camera controls / simulated camera generator
- Trigger Box QSG — printed p.17: return Trigger Box to normal working mode
Additional Community Notes¶
[FORUM — talk.mrmoco.com] DIY cable wiring for RED V-Raptor / Komodo EXT port — bypasses expander modules.
If the standard sync cable or expander blade is unavailable, the RED V-Raptor and Komodo can be connected using a RED EXT-to-Flying-Lead cable (RED part: 9-pin EXT to Flying Lead). Solder two BNC male connectors onto the flying leads as follows: GND wire → sleeve/outer ring of both BNCs; GPI wire → Trigger BNC; GPO wire → Sync BNC. Mate to the Epic/Phantom MRMC Sync Cable.
@runimation's cleaner variant: solder the three relevant flying leads from the RED EXT cable directly onto a LEMO FGG.0B connector — this plugs into the 4-pin Lemo port on the universal sync box and provides both trigger and sync in a single cable with no breakout box or expander blade required. Set V-Raptor to "Pulsed" trigger mode for correct cut-on-slate and cut-at-move-end behaviour.
Colour code reference (from jmahood, 2022-09-06): see the RED V-Raptor EXT wiring diagram (posted by jmahood on the forum). Tim HC confirmed: GND to outer sleeve on both BNCs, GPI to trigger BNC, GPO to sync BNC.
"Just solder 3 connectors of a flying lead RED Ext cable to a LEMO FGG.0B plug and you get trigger and sync without a breakout box." — @runimation, confirmed by Tim HC
Source: RED V Raptor/Komodo Sync (2022–2023, Tim HC + runimation + jmahood)
Related Issues¶
- See also: RT-14 12V Chip Blown — Trigger Box Loses All LEDs and Functionality
- See also: Sony FX6 and Burano — Trigger vs Genlock / Sync Compatibility
- See also: High FPS Sync - Flair May Read Every Other Pulse Above ~800 FPS
- Transport Vibration / Rolling Cases Rattle Internal Connectors Loose
- RED V-RAPTOR Stuck at Amber LED — Won't Power On, Hard Reset Procedure
- RED V-RAPTOR on Bolt Arm — XLR-4 to XLR-3 Power Adapter Wiring
- Sync / Phase Lock Lost At End Of Run
- RED Camera Sync and Trigger — DSMC1, DSMC2, Komodo, V-Raptor, Helium
- RED Monstro End Trigger Sticks On — Hold / GPIO / Pulse Settings