Hardware: BlackWidow V4 Low-profile HyperSpeed (keyboard firmware 1.4), HyperSpeed dongle
(USB PID 0x02C9), Basilisk V3 (PID 0x0099). Windows 11 Home 26200.
Software: Synapse 4 stable 4.0.827, proxy RzChromaSDKProxy_v1.2.3.2.
Issue: in wireless (HyperSpeed) mode, Chroma SDK applications cannot light the keyboard.
lighting-engine.log shows the keyboard registered as the wired product id with no handle:
addDevicesToChromaStudioEngine() productId:716 ... device handle:undefined
In wired mode the same line reads "productId:716 ... device handle:3" and everything works.
Synapse also shows no keyboard lighting tab in wireless mode. SDK calls still return
result:0, so applications cannot detect the failure.
The hardware path is fine: raw Razer HID commands sent through the dongle (transaction
id 0x9F) are accepted and displayed by the keyboard, both custom frames and built-in effects.
So the issue looks like a Synapse-side mapping of the dongle (0x02C9) to the wired
product (0x02CC / 716).
Related: the Synapse 4 beta update of 4 Oct 2026 (Apps\Common\LampArray module) broke
the internal SDK engine init (RzChromaSDKEngine ... !this.isInit), leaving all devices
dark while a Chroma app was running. Reverting to stable 4.0.827 fixed that part.
Expected: the keyboard should be bound to the Chroma SDK engine with a valid handle in
wireless mode, as it is in wired mode.