Samsung Galaxy S24 Ultra Error DISP-MURA-HW01: Grainy Display Low Brightness Mura
Sub-pixel luminance non-uniformity across the Dynamic AMOLED 2X panel caused by low-current drive variance at lower brightness levels (Mura effect). This manifests as a fine grain or sandpaper texture when driving sub-pixels under ~10-15 nits due to microscopic threshold voltage (Vth) shifts in the LTPS/LTPO thin-film transistor backplane.
Hardware Diagnostic Matrix
Spec Ref #cc9f94f3Required Diagnostic Tools & Instrumentation
Multimeter Probing Targets & Circuit Tolerances
Bench Calibrated ±5%| Test Point / Circuit | Target Nominal Spec | Expected State | Fault Condition |
|---|---|---|---|
| Main Logic DC Bus | 3.3V / 5.0V DC (±0.1V) | Stable DC Potential | <2.9V (Brownout / Sag) |
| Thermistor / NTC Sensor | 10kΩ - 100kΩ @ 25°C | Smooth Thermal Curve | 0Ω (Short) or ∞ (Open) |
| Safety Ground / PE Continuity | < 0.5Ω Resistance | Solid Earth Bond | > 1.0Ω (Floating Chassis) |
Common Symptoms & Fault Manifestations
- Sandpaper or canvas-like grain visible on dark gray and solid color backgrounds under 20% brightness
- Visible micro-luminance banding or uneven pixel dithering in low-light dark mode
- Persistent texture that does not move with screen scrolling or software element transitions
Root Causes & System Failure Modes
LTPO TFT backplane threshold voltage (Vth) manufacturing variance failing sub-pixel compensation at sub-microamp drive currents
De-Mura calibration data lookup table (LUT) mismatch within the Display Driver IC (DDIC) flash
Pulse Width Modulation (PWM) duty-cycle current starvation across the DDI ELVDD/ELVSS power rails
High-Voltage & Mechanical Safety Isolation
Prior to opening access panels, disconnecting terminals, or probing wiring, perform complete lock-out / tag-out (LOTO). Disconnect all AC mains, DC string isolators, and lithium battery banks. Allow internal smoothing capacitors at least 3 to 5 minutes to dissipate stored residual energy below safe threshold (<30VDC).
Step-by-Step Diagnostic & Resolution Procedure
Software Color Profile & LUT Verification
Navigate to Settings > Display > Screen Mode. Adjust the 'Vividness' slider to Level 2 or Level 3 to evaluate DDIC color mapping. Disable 'Extra Dim' in Accessibility/Quick Settings to verify if the issue is exacerbated by synthetic digital luminance scaling rather than raw hardware drive.
Hardware Service Mode Self-Test
Open the Phone dialer and enter *#0*# to launch hardware diagnostics. Cycle through RED, GREEN, BLUE, and LOW LUMINANCE test screens under a dark environment. Use a 50x digital microscope to inspect if sub-pixel clusters fail to illuminate evenly or exhibit static transistor gate leakage.
De-Mura Re-Calibration or Firmware Flash
Flash the latest stock CSC binary using Samsung Odin to ensure latest DDIC compensation parameters are loaded. If Mura persists and delta-E variance exceeds factory tolerance (>2.5 JNCD on dark gray fields), the defect is inherent to physical transistor backplane variance and requires panel assembly replacement.
OLED Display Assembly Replacement
Power down device, heat display assembly to 80°C on a thermal pad, decouple adhesive perimeter using an isopropanol-damped pry pick, disconnect the display FPC from the motherboard, and install an OEM Service Pack display module (GH82-33433A) pre-calibrated with factory De-Mura LUT.
Hardware Reset & Fault Clear Sequence
Controller ProcedurePrevention & Routine Maintenance Guidelines
- Avoid forcing sustained ultra-low nit modes with third-party screen dimmer apps that corrupt hardware-level PWM curves
- Always apply official One UI maintenance updates which push refined DDIC LUT compensation algorithms
Frequently Asked Diagnostic Questions
What does error code DISP-MURA-HW01 indicate on Samsung Galaxy S24 Ultra?
Sub-pixel luminance non-uniformity across the Dynamic AMOLED 2X panel caused by low-current drive variance at lower brightness levels (Mura effect). This manifests as a fine grain or sandpaper texture when driving sub-pixels under ~10-15 nits due to microscopic threshold voltage (Vth) shifts in the LTPS/LTPO thin-film transistor backplane. In engineering telemetry, it indicates grainy display low brightness mura requiring circuit verification.
What are the primary triggers causing error DISP-MURA-HW01?
Diagnostic bench telemetry isolates the following common root causes: LTPO TFT backplane threshold voltage (Vth) manufacturing variance failing sub-pixel compensation at sub-microamp drive currents; De-Mura calibration data lookup table (LUT) mismatch within the Display Driver IC (DDIC) flash; Pulse Width Modulation (PWM) duty-cycle current starvation across the DDI ELVDD/ELVSS power rails.
How do I reset and clear Samsung error DISP-MURA-HW01?
Perform a hardware partition cache wipe: Turn off device, connect to PC via USB-C, press and hold Volume Up + Power until Android Recovery appears, select 'Wipe cache partition', confirm, and select 'Reboot system now'. If the error status repeats immediately after clearing, discontinue clearing and test circuit continuity.
Can I safely resolve error DISP-MURA-HW01 without specialized shop tooling?
This fault is graded as Advanced difficulty with Medium severity. Standard diagnostics require an insulated digital multimeter and appropriate hand tools. Always observe high-voltage isolation procedures.