Roku Pro Series Mini-LED (R8B5 2024 / R8C5 2025): quick sheet

Covers: Roku-branded Pro Series mini-LED QLED TVs: 2024 models 55R8B5, 65R8B5, 75R8B5 (65R8BX also listed) and the 2025 refresh (e.g. 65R8C5). Sizes 55, 65, 75 in. Roku's own TVs are built by outside manufacturers; the builder is not confirmed.

Cross-checkedBrands: Roku7 components

Roku's top TV: mini-LED backlight with local dimming, 120 Hz panel, four HDMI inputs (two HDMI 2.1), and a thick 'shadowbox' design that hangs flush against the wall with built-in cable management. Weight is high for the size (about 62 lb for 65 in).

Safety first

Unplug and wait before opening.
Live tests on power board / LED driver are caution work.
Two people for lifting (about 62 lb at 65 in).

How it works

Power board feeds main board and mini-LED driver; main board runs Roku OS and dimming control.

Mini-LED boards sit behind diffuser; dark blocks mean a zone or board fault.

Roku TVs have a physical reset (button or Power + Find My Remote, depending on model) for units that will not respond to the remote.

Components & tests

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Official manufacturer documentation

Always confirm values against the tech sheet for the exact model.

OnCall Tech is a reference tool for trained technicians and can make mistakes. Always disconnect power and confirm with the manufacturer's documentation before you work. © 2026 OnCall Tech. Original content; not a reproduction of any manufacturer document.Generic part photos (not of this brand): LCD TV with the panel removed, showing the grid of lit LED backlights by RobertKuhlmann, CC BY-SA 3.0

Diagnostic guides for this appliance

Guide · TV

Soundbar won't turn on with the TV, or TV remote won't control its volume (HDMI-CEC)

One-remote control depends on HDMI-CEC over the ARC/eARC cable. Disabled CEC, the wrong HDMI port, an optical connection, a poor cable or a TV update that switched settings off cause nearly all of these calls.

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Soundbar audio cuts out, pops or drops with movies/Atmos (ARC/eARC)

Dropouts usually come from an unstable ARC/eARC handshake or a format the chain doesn't handle well. Work through cable, firmware, CEC conflicts and the TV's digital audio format; optical is a stable fallback without Atmos.

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Projector won't turn on or shuts off (reading the indicator lights)

Projectors protect themselves: overheating, lamp at end of life, and lamp-cover interlocks all stop the light source. Read the indicators against the model's table, then fix airflow, lamp seating or lamp life.

6 steps ~30 mineasy

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