Samsung Support Request โ HDMI 4K/HDR Fails on QN85QN900F > TV Model: Samsung QN85QN900F (85โ Neo QLED 8K) One Connect Box: Original Issue Summary: We are experiencing a persistent HDMI input issue with our Samsung QN85QN900F where the TV fails to display any 4K signal directly from source devices. It briefly flashes a signal and then goes to "No Signal." This affects both SDR and HDR depending on the source, and occurs regardless of HDMI port used (tested all). --- ๐งช Devices Tested: PlayStation 5 Standard (Model CFI-1215A) PlayStation 5 Pro (brand new, July 2025 release) Denon AVR-X3700H Receiver All with certified 8K Ultra High-Speed HDMI cables (with QR verification) --- ๐ What Weโve Confirmed: All devices and cables work perfectly with 4K HDR on older Samsung TV (MU series) and LG 4K TV The Denon โ QN900F path works only in SDR (4K HDR fails, no signal) When PS5 is plugged directly into the QN900F, it fails to display 4K at all โ only 1080p works TV settings have been verified: Input Signal Plus is enabled for all HDMI ports Game Mode off, AI/Intelligent Mode off Factory reset performed Power drain and EDID reset process followed TV firmware is updated (or confirmed no update available) --- ๐ง Our Diagnosis: This appears to be a failure of the TVโs HDMI EDID handshake system or HDMI signal processing circuit, specifically when receiving full-bandwidth 4K or HDR signals โ even from known-good certified sources. Denon AVR only works because it reformats the signal before reaching the TV. HDR and Enhanced mode signals fail every time, regardless of port or cable. --- โ Request: We are not asking for basic troubleshooting at this point, as everything has been thoroughly tested and isolated. We are requesting: Escalation to a technical service team Evaluation of HDMI board or One Connect box On-site service visit or replacement options if applicable Please advise on how to proceed with this repair under warranty.
