It has been confirmed to work on the Z420 (v2) and is expected to work on the Z620 and Z820 with the same 5‑pin fan header layout. Always verify the pinout of your specific motherboard before attempting the patch.
Before running intensive workloads, check for firmware updates for your AIO cooler.
: The Xeon E5‑2687W v2 has a TDP of 150W. A high‑quality air cooler (such as the Z440/Z640 air cooler or a third‑party tower cooler with a 120mm fan) can easily handle this load, with typical operating temperatures between 45°C and 55°C under normal workloads. The BIOS's insistence on liquid cooling is thus an over‑restrictive policy rather than a physical necessity. 528cpu requires liquid cooling solution patched
HP also offered a "Performance" air heatsink for some models. This cooler often includes the necessary wiring to satisfy the BIOS without requiring a full liquid cooling setup. HP Support Community Important Precautions Thermal Safety
If you prefer to resolve the 528 error code without cutting or jumping physical wires, you can employ a series of firmware adaptations: 1. Disabling F1 Boot Prompts It has been confirmed to work on the
Yes, but you will still see the 528 error unless your cooler provides a second tachometer signal on pin 5. Many aftermarket coolers use a standard 4‑pin PWM header, leaving pin 5 unconnected. You would then need the pin‑5 patch or a SATA‑powered pump arrangement.
The workstation's BIOS is programmed to check for a specific hardware configuration before allowing a boot. If you install a processor with a high TDP (like a Xeon E5-2687W), the BIOS expects to see a liquid cooler connected to the motherboard's fan headers. : The Xeon E5‑2687W v2 has a TDP of 150W
: Bypassing this warning with a "patch" means you are overriding a safety feature. If you use a weak air cooler on a 150W TDP processor, your system may overheat or shut down under load.
The 528CPU is optimized to operate near its maximum thermal limit. Liquid cooling provides the necessary headroom to prevent instantaneous throttling.
: Tying Pin 5 directly to ground closes the circuit, signaling to the BIOS that the mandatory liquid cooling thermal kit is attached. Summary of Resolution Paths Your Hardware Setup Root Cause of 528 Error Required Patch Actions Factory OEM Liquid Cooler Broken pump or dead tachometer line.