6 components coveredField manual · TV
TCL 5-Series QLED (S535 / S546 / S555): quick sheet
Covers: TCL 5-Series quantum-dot (QLED) sets: S535 Roku TV (2020), S546 Google TV (Google TV version of the same generation) and S555 Roku TV (2022). Sizes roughly 50-75 in (TCL product pages; Reviewed, Tom's Guide and Tech Steve reviews).
Step-up TCL with a QLED panel and full-array backlight split into zones (TCL calls them local dimming or contrast control zones). 60 Hz native panel. The repair picture is the same as the 4-Series (backlight strips and power board lead the list) but the backlight has more zones and strips and parts are model-version specific.
Safety first
- Unplug the set and wait several minutes before opening the back: the power-supply primary capacitors can hold a dangerous charge after unplugging.
- Power-supply and LED-driver checks with the set plugged in are caution work: insulated probes, one hand, no jewelry, and never touch the primary (hot) side.
- Lay the panel face-down only on a clean, padded, flat surface; open-cell panels crack from twisting or pressure on the glass.
- Two people for 55-inch and larger sets; lift by the frame, never by the screen.
- Use ESD protection when handling the main board and T-con; the flat flex cables tear easily.
How it works
The power board feeds the main board and backlight drive. The main board (Roku or Google TV) also computes zone dimming and sends brightness data to the backlight driver while sending video to the T-con.
A quantum-dot film in front of the blue LEDs widens the color range. Because the LED array is split into zones, a failed string can show as a dark block or patch rather than a fully dark screen.
Reviewers measured fewer active zones than marketed on some sizes; zone counts vary by size and year (S535 about 48 on 55 in; S555 'up to 40/80' claims).
Components & tests
Unlock all 6 components, specs, service mode and teardown
Full library + AI assistant for $34.90, one time.
Get lifetime accessOfficial 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): Clothes dryer with its vent duct in a small laundry closet by Introspectivedsgn, Pexels License
