Defeating Vendor Lock-Ins: "Liebert GXT4."

Certain double-conversion UPS units by Liebert (in my case -- a GXT4-2000RT120) appear to contain a boobytrap whereby off-the-shelf (needs two 12v/80mm) high-efficiency/quiet fans will not operate -- the boot will abort with a Fan Out of Order error.

The pill: install a 100 ohm wirewound resistor in parallel with the front fan connector (on each side, will need to snip off the original plug and solder to a standard PC 4-pin extender.) This defeats the current sensor which expects to see the original (~0.4A max) fans; but not to the extent where the death of one or both of the new fans will fail to trigger the alarm.

This entry was written by Stanislav , posted on Friday January 29 2021 , filed under Chumpatronics, Cold Air, Hardware, NonLoper, Reversing . Bookmark the permalink . Post a comment below or leave a trackback: Trackback URL.

2 Responses to “Defeating Vendor Lock-Ins: "Liebert GXT4."”

  • neetgar says:

    Hey thanks for the tip! I was able to modify a GXT4-700RT120, which has a single fan at the back, with a BL040 on hand and aa 3D printed funnel/duct. This fan is rated for 0.3A but I haven't confirmed that 40ohms is the correct resistance for the failure threshold.

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