Czy wolisz polską wersję strony elektroda?
Nie, dziękuję Przekieruj mnie tamKD-55X8508C
Hardware architecture
• SoC: MediaTek MT5890 (ARM Cortex-A17 dual core @1.1 GHz, Mali-T624 GPU)
• Memory: 1.5 GB DDR3, 8 GB eMMC (≈4 GB user)
• Video chain: Mainboard → LVDS → T-CON → Panel; LED driver integrated on PSU (G6 board)
• Power rails: 12 V, 24 V (LED), standby 3.3 V/5 V, generated on PSU; panel VGL/VGH on T-CON
Typical fault signatures and root causes
Blink codes (red LED) – protection shuts TV down:
• 2 × : PSU OVP/OCP – bad primary PWM IC or shorted MOSFETs
• 3 × : Main ↔ PSU I²C fail – often mainboard
• 4 × : Panel balancer – LED driver or harness
• 5 × : T-CON or panel Vcom drift
• 6 × : Back-light open/short – single LED strip failure (>70 % of repairs)
• 7 × : Over-temperature – clogged vents, sensor open
• 8 × : Audio DSP or software crash – eMMC corruption
Diagnostics flow:
a) Verify AC input, bypass surge bar.
b) Measure PSU secondary rails with isolation transformer; scope ripple (<50 mV pp).
c) For 6-blink, perform “flash-light test” to confirm video present and LEDs off. Replace full strip set; mixing new/old increases current mismatch.
d) Boot-loop or green-Android: USB firmware recovery, if fail → replace mainboard (1-894-595-11 or 1-894-596-11; match suffix). Reballing eMMC rarely permanent.
Software/Android issues
• Post-2019 Google Play Services updates stress limited RAM; clear cache or disable auto-updates.
• Slow UI: root cause mainly “Sony Shelf” and “X-Reality demo” services; can be disabled in Developer → Apps.
• Bluetooth voice remote lag fixed in FW 3.533; earlier FW should be upgraded by USB to avoid OTA lock-up.
• No HDR in launch FW; EU models gained HDR10 with v3.149 (2016) but tone-mapping is basic (8-bit panel, 350 nit peak).
Picture quality considerations
• Panel is IPS-type; black level ≈0.15 cd/m², contrast ≈1200:1. Use Cinema Pro + Backlight = 10, Contrast = 90, Gamma = -2 for night viewing.
• HDMI 2 & 3 support full 4 K @ 60 Hz 4:2:0; enable “HDMI Enhanced Format” for 4:4:4 PC input.
Edge-LED back-lights are driven in series strings; one open LED raises Vf beyond driver limit, invoking 6-blink. Replacing only the open diode forces current through aged neighbours and leads to repeat failure; entire strip set replacement equalises forward voltages.
The eMMC wears out due to frequent Dalvik cache writes; once bad blocks grow, Android services crash → 8-blink or boot-loop. Replacement requires BGA rework and secure-boot key transfer – uneconomical for field.
Implementation / repair sequence for 6-blink:
KD-55X8508C is a 2015 55-inch 4 K Android TV with decent SDR picture but limited HDR and ageing hardware. The most frequent hardware failures are LED back-light (6-blink) and eMMC flash corruption; both are repairable but may not be cost-effective versus replacement. Firmware support ends at Android 7; safe operation now recommends network isolation. For troubleshooting, first read LED blink count, verify PSU rails, then decide between board-level repair and full set replacement, keeping safety and environmental regulations in mind.
User question
emmc kd-55x8500c
Artificial Intelligence Response
Direct answer to the question
• In the Sony KD-55X8500C the Android operating system is stored on an on-board BGA-153 eMMC device (typically 8 GB – Toshiba THGBMHG6C1LBAIL, Samsung KLM8G1GEME-B041, or SK-Hynix H26M52103FMR).
• After 4-8 years many sets show classic NAND wear-out: boot loops, eight-blink error, or total no-boot.
• Long-term cure = replace and pre-flash a new, compatible eMMC or fit a new/used mainboard; temporary cure = attempt USB firmware recovery.
Detailed problem analysis
Role of the eMMC
• Holds boot ROM, secure boot keys, Android partitions (boot, system, vendor, userdata), firmware upgrade area and DRM/RPMB blocks.
• Interface: eMMC v4.5/4.51, 1.8 V I/O, 3.3 V Vcc, clock ≤ 200 MHz.
Typical failure mechanism
• Finite P/E cycles (≈ 3 k-5 k for 15-nm MLC) → accumulated bad blocks.
• Internal controller eventually runs out of spare blocks → uncorrectable read errors shown in UART log ( mmc_read_blocks failed , EXT4-fs error ).
• Abrupt power loss during a write accelerates corruption of FTL metadata.
Field symptoms
• Endless “Sony / Android” boot animation.
• Red standby LED 8-blink code after power-on.
• Green Android robot with exclamation sign in recovery.
• Extremely slow UI, apps constantly crashing, factory reset fails.
Diagnostics hierarchy
a) Rule out PSU/LED driver: confirm 12 V, 5 V, 3.3 V rails present.
b) Force USB-firmware update (FAT32, last PKG from Sony). If update hangs or reboots → eMMC cannot accept writes.
c) Serial console (3.3 V UART on CN3203) shows “MMC: bad CRC” / “Kernel panic – not syncing: VFS: unable to mount root fs” → 99 % probability of worn eMMC.
d) Service menu §041 “eMMC Health” (if the set still boots) – look for WORN_OUT or > 0x05 error count.
Repair decision matrix
Current information and trends
• 2023-24 repair forums (Reddit r/TVRepair, Badcaps) report an uptick of Sony Android-TV eMMC deaths as the 2015-2017 fleet ages.
• Technicians increasingly use larger-capacity, higher-endurance eMMC 5.1 parts (e.g., Samsung KLMBG2JETD-B041 16 GB) – backward-compatible if clock limited to 200 MHz.
• Some labs ship pre-flashed “drop-in” chips (~USD 35) containing generic KD-55X8500C dump; still requires soldering.
• Sony’s newer Google-TV sets moved to UFS Flash with higher endurance, reducing—but not eliminating—storage-wear issues.
Supporting explanations and details
• Why 8 blink? 8-blink on Sony “C” chassis = Audio/SW error, but service manuals note “IC6501 (eMMC) NG” as a primary trigger.
• Write-amplification: Android’s Dalvik/ART caching, Play-store auto-updates, and logd journalling can generate > 1 GB/day writes—far beyond the design assumption for a TV.
• Analogy: The eMMC is the TV’s SSD; once its spare blocks are gone, the controller is like a hard-disk with too many bad sectors: the OS can’t even read its own shoestrings.
Ethical and legal aspects
• DRM / RPMB region contains legally protected Widevine & PlayReady keys. Copying or distributing dumps that include another device’s keys violates copyright and streaming-provider T&Cs.
• Proper disposal: old eMMC contains RoHS-exempt lead spheres; recycle according to WEEE in EU, R2 in US.
• Data privacy: although most personal data on a TV is trivial, best practice is to shred or keep the failed chip.
Practical guidelines
• Before opening the set, photograph connector layout; LVDS cables are fragile.
• Use ESD wrist strap and 100 nF/10 Ω discharge path—MediaTek SoC GPIOs are 2 kV HBM sensitive.
• Bench test with current-limited (3 A) isolation transformer to avoid LPS short damage.
• Always verify 1.1 V CPU core rail ripple (< 30 mVpp) to rule out power integrity faults that mimic eMMC errors.
Possible disclaimers or additional notes
• No “service menu reset” will repair worn NAND; at best it reduces write load and buys days/weeks.
• A minority of boards fail due to cracked BGA solder joints under the eMMC (thermal cycling). In such cases reflow may revive temporarily, but plan to replace the chip.
• If boot-loader fuses (TSMC e-fuse row) are blown, a donor eMMC will not boot—rare but documented.
Suggestions for further research
• Investigate replacing eMMC with BGA254 UFS-to-eMMC adapter for higher endurance (experiment in mobile-phone repair community).
• Develop open-source Android-TV images with log-reduction and read-only /system partition to cut write traffic.
• Study thermal profiles of mainboard ‑ backside copper pour vs. eMMC temperature to model accelerated wear.
Brief summary
The KD-55X8500C’s on-board eMMC is the single most common failure point: limited-endurance NAND cells wear out, preventing Android from booting and triggering boot loops or 8-blink codes. Confirm good power rails, attempt USB firmware recovery, then choose between (a) professional eMMC BGA replacement with correct pre-programmed image or (b) full mainboard swap. For non-technicians, a new TV may be more economical, but skilled repair can extend service life reliably when the correct procedures and tooling are used.