Causes
- Panel-level mura (luminance non-uniformity) — OLED panels show cloud-like patches of uneven brightness and color because each subpixel's voltage response varies slightly across the panel. On the Thor's 6-inch main AMOLED and 3.92-inch bottom display this shows up as blotchy areas, most noticeably on gray or dark backgrounds, and the early panels shipped with more visible mura than later ones.
- Low brightness and dark mode exaggerate it — the mura effect is worst at the bottom of the brightness range (roughly 0-20%), where subpixel voltage differences are amplified. The Thor's default dark Android UI means many owners only ever see the screen in the conditions where mura is most obvious.
- Firmware gamma and color handling in early builds — the first Thor firmware handled dark gray levels poorly, which made both color shift and mura look worse than the panel was capable of. AYN later added an OLED Ultra Black Mode option in Odin Settings → Advanced Settings specifically to "significantly improve color shift and mura effect" at low brightness.
- Temporary image retention mistaken for mura — the Thor's OLED panels are prone to image retention (ghosting), which appears as patchy, fixed-looking shapes that are easy to confuse with mura. The device runs a screen refresher after being idle for a bit, and retention fades over time — but while it's visible it looks exactly like a mura defect.
- Panel-to-panel variance — some Thors are nearly uniform while others are blotchy out of the box. If the unevenness is clearly visible at normal gaming brightness (not just near-zero brightness), your unit is on the bad end of that variance curve and qualifies for a panel swap.
How to Fix
- Update the Thor to the latest OTA — go to Settings → System → Thor OTA and install any available update. A quality-of-life OTA improved OLED uniformity for dim gaming, and a later update added OLED Ultra Black Mode; these two changes resolve most mura and color-shift complaints, so do this before anything else.
- Enable OLED Ultra Black Mode — open Settings → Odin Settings → Advanced Settings and turn on OLED Ultra Black Mode. This makes the screen rely on true blacks instead of lifted gray, which dramatically reduces the appearance of mura and color shift when dark mode is selected at low brightness.
- Clear temporary image retention first — if you see patchy areas right after a gaming session, leave the Thor idle (closed or on the idle screen) so the built-in screen refresher runs, or display a bright white image for a few minutes to accelerate clearing. Only treat the blotches as mura if they persist after a refresh — many "mura" reports turn out to be retention that clears on its own.
- Avoid the worst brightness range — raise the brightness above roughly 20-30% when you can; mura is fundamentally a low-brightness artifact and becomes nearly invisible at normal gaming brightness. In a dark room, prefer dark mode at moderate brightness over minimum brightness.
- Verify with a uniformity test — display solid gray images (10%, 20%, and 50% gray) on both screens and inspect for fixed blotches. Shapes that stay in the exact same place across all brightness levels and never fade are mura; shapes that shift or fade with time or after the refresher are retention.
- Contact AYN for a panel replacement if it's severe — if mura is clearly visible at normal brightness even with Ultra Black Mode enabled and the latest OTA installed, email [email protected] with your order number and photos of the gray test screens. AYN has swapped panels for Thor owners with defective displays under warranty.