Onkyo Receiver 4K/120Hz Passthrough Not Working With PS5: Fix

If your PS5 does 4K/120Hz fine plugged straight into the TV but not through your Onkyo receiver, the console is fine — the receiver is the bottleneck. Many Onkyos have only one HDMI 2.1 port (the rest are 2.0, capped at 4K60), and some early HDMI 2.1 Onkyos shipped with a firmware bug that broke 4K/120 passthrough until patched. Here's the chain fix.

Fix it

1. Use the receiver's actual HDMI 2.1 port. On most Onkyos only one input (often HDMI 1 or 2, labeled 8K) is full 2.1. Move the PS5 to that port — the others cap at 4K60.
2. Send the receiver's output to a 4K120 TV input. The Onkyo's HDMI OUT (MAIN) must go to a HDMI 2.1 (4K120) input on the TV — many TVs have only one or two.
3. Update the receiver firmware — critical for early 2.1 Onkyos. Some HDMI 2.1 Onkyo/Pioneer models had a documented 4K/120 passthrough bug fixed by a firmware update. Update via the network/USB before anything else.
4. Use certified Ultra High Speed (48 Gbps) cables on both hops. PS5 → receiver and receiver → TV. A cable that can't sustain 48 Gbps drops to 4K60 or black-screens at 120Hz.
5. Set the PS5 output and power-cycle. PS5 Settings > Screen and Video > enable 120Hz + VRR. Then unplug PS5, receiver, TV 30+ seconds; power TV first, then receiver, then PS5. If the PS5 still won't show 120Hz/VRR even direct to the TV, the PS5 4K HDR but no 120Hz/VRR settings fixes sort the console and TV side.

The eARC workaround (most reliable)

If passthrough still won't do 4K/120 — or the Onkyo caps at 40 Gbps — bypass the receiver's video path:

• Connect the PS5 directly to the TV's 4K120 HDMI 2.1 port, and run eARC from the TV back to the Onkyo for sound. The PS5 gets full 4K/120/VRR from the TV, and the receiver still gets the audio. This sidesteps the receiver's video bandwidth entirely. If the eARC return then goes silent, the Onkyo no-sound-from-TV-apps fix covers the CEC and routing settings.

FAQ

4K/120 works on my TV but not through the Onkyo. The receiver is the bottleneck. Use its single HDMI 2.1 port, update firmware, use certified cables on both hops, and confirm its output goes to a 4K120 TV input.

My Onkyo says HDMI 2.1 but caps at 4K60. Only one of its ports is true 2.1 (often the 8K-labeled one); the rest are 2.0. Move the PS5 there. For no-picture or 4K HDR (not 120Hz) problems through the receiver, see the Onkyo no-picture / 4K HDR passthrough fix.

It worked then broke / never worked at 120Hz. Early HDMI 2.1 Onkyos had a passthrough firmware bug. Update the receiver's firmware — that fixed it for many.

Best PS5 + Onkyo layout for 4K/120? PS5 → TV's 4K120 port, then eARC TV → Onkyo for audio. It avoids the receiver's video bandwidth limits.