Video & projection
Hollyland Mars 400S Pro II troubleshooting
The Hollyland Mars 400S Pro II problems live-event techs bring to Ask Roadie most (also called Mars 400S Pro). Pick your symptom, or describe your own in plain words, and get the likeliest fix first, with the manual page when there is one.
Common Mars 400S Pro II errors & problems
What techs run into most, and what's usually behind it. The step-by-step fix for your exact unit is in Ask Roadie.
- Step-by-step fixGet the fix →
"No Video" shown on the transmitter (TX not receiving a source image)
Likely cause: The TX only locks known progressive/interlaced formats without CEC handshakes or on-screen overlays; a bad cable, unsupported format, or CEC can leave the TX with no valid input.
- Step-by-step fixGet the fix →
Blackmagic (BMD) switcher screen turns black when fed 1080p60 over SDI from the RX
Likely cause: The BMD input rejects true 1080p60; dropping to a p50/i50 format it supports restores the picture.
- Step-by-step fixGet the fix →
Color blocks/garbage on a Mars monitor after turning on the LUT function
Likely cause: A 3D-LUT conflict corrupts the displayed frame; disabling the LUT restores a normal picture.
- Step-by-step fixGet the fix →
Frame drops or dropouts when several Mars units are powered on together (3+ TX/RX in one area)
Likely cause: Multiple units contend for the same 5GHz spectrum; separating channels and units reduces mutual interference that causes the dropouts.
- Step-by-step fixGet the fix →
Frame rate on the transmitter does not match the frame rate set on the camera
Likely cause: The link processes only integer frame rates, so fractional rates are rounded for the on-screen readout.
- Step-by-step fixGet the fix →
Image freezes or shows mosaic in the HollyView phone app
Likely cause: The phone Wi-Fi link and the TX radio interfere at close range; separating them clears the app feed.
- Step-by-step fixGet the fix →
Mirrorless/DSLR camera screen goes black when recording (via the TX)
Likely cause: The camera, not the Mars, disables one output during 4K record; routing through a recorder gives the TX a persistent HDMI feed.
- Step-by-step fixGet the fix →
Screen shows "CH-" with no channel number on TX or RX
Likely cause: Under-powered USB-C supplies brown out the RF stage so no channel locks; re-pairing rebinds an RX that lost its link to the TX.
- Step-by-step fixGet the fix →
Signal bar 2 shows an "X" on the transmitter screen
Likely cause: The TX always displays two RX slots; an empty slot reads as X and is not a fault.
- Step-by-step fixGet the fix →
Some SDI devices reject the 1080p50/60 signal from the RX (not just BMD)
Likely cause: The non-compliant SMPTE payload flags cause strict SDI receivers to reject the stream; a re-clocked/converted signal or a more tolerant format is accepted.
- Step-by-step fixGet the fix →
Sony mirrorless camera screen turns black when connected to the TX
Likely cause: Sony sends a resolution/overlay/CEC combination the TX cannot lock; forcing a clean 1080 output without info display or control fixes it.
- Step-by-step fixGet the fix →
Updating firmware / which firmware version is current
Likely cause: Running the latest, matched firmware on both ends prevents pairing/compatibility glitches and applies the manufacturer power/stability fixes.
Not on the list? Describe it your way, or paste the error code off the display. Ask Roadie works the problem with you until it's fixed or you have a clear next move.
How Ask Roadie helps with the Mars 400S Pro II
- 1. Pick the Hollyland Mars 400S Pro II. It's already in the list.
- 2. Describe what you're seeing. In your own words, or the error code off the screen.
- 3. Get the likeliest fix first. Steps in order, the manual page when there is one, and a note when other techs have confirmed it.
- 4. Still broken? Tap 👎 and it keeps going from where you left off.
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