My monitor arm won't hold its position — how do I fix it?

Usually the spring tension is set for a different weight than your screen. If the monitor sinks, increase the tension; if it creeps up or springs back, decrease it. Adjust in small steps and test after each. If it still will not hold at full tension, check the screen’s weight — with its stand removed — against both ends of the arm’s stated range.

1. Find which way it drifts. A screen that sinks slowly has too little tension for its weight. One that rises on its own, or will not stay low, has too much. A screen that droops forward or tilts down rather than moving as a whole has a loose tilt joint, not a spring problem — see step 4.

2. Adjust the tension. Most arms adjust with a hex key in a screw at the joint between the two arm sections or near the base; check the manual for which way is stronger. Turn a few times, move the screen up and down, and check whether it now stays where you leave it. Setting spring tension on a monitor arm covers the method in detail.

3. If tension runs out, check the weight. Weigh the monitor alone, without its stand, and compare with the arm’s range — both ends. A screen lighter than the minimum can be too light for even the lowest tension and will keep rising. In our monitor arms hub, the Acer, HUANUO and Invision take screens of 2 to 9 kg (4.4 to 19.8 lb), and the Ergotron 1.8 to 10 kg (4 to 22 lb). A curved or large screen near the top of the range can also sag if it is pushed far out, where it pulls hardest on the spring.

4. Tighten the other joints. The tilt joint behind the screen and the swivel joints along the arm have their own friction screws. A screen that nods forward needs the tilt screw tightened; an arm that swings sideways on its own needs the swivel joints tightened, or the clamp checked — an arm whose clamp has loosened on the desk will lean. Measuring desk thickness for a clamp helps if the clamp never sat right.

5. If nothing helps, the spring may have failed. A gas spring that has lost its charge does not recover with adjustment; it is a warranty matter, not one to open up yourself — a spring under load can release suddenly. Warranties vary widely: 10 years on the Ergotron, 2 years on the Invision and 12 months on the Acer, while the HUANUO’s listing gives none. The HUANUO uses a mechanical steel spring rather than gas, which HUANUO tested to 50,000 cycles.