Quick answer: a monitor arm that slowly drifts down, springs up or won't stay put is usually not broken — the spring tension simply doesn't match the monitor's weight. Fix it by turning the tension screw in small steps with the monitor mounted. A genuinely failed gas spring looks different: the monitor is within the arm's rated range and the tension is at maximum yet it still sinks, the holding force fades over days, or there is visible oil at the cylinder. That is a warranty claim: register, then contact the shop with your order number and a photo or video.
How a gas-spring monitor arm "holds" — and why it sags
A gas-spring arm doesn't lock the screen with a rigid mechanism. It uses the pressure in a gas cylinder to counterbalance the monitor's weight. When the two forces are equal, the screen stays where you let go. If the spring is weaker than the monitor, the screen drifts down; if it is stronger, the screen floats up.
That is why every arm has a tension screw, and a designed weight range. The ZEN-0 takes 17–32" screens up to 9 kg each, the ZIMPLEX goes to 10 kg, and the heavy-duty HYPERION covers 17–49" screens from 2 to 20 kg. A monitor outside that range will never balance, however far you turn the screw.
Symptom check: sagging, springing up, tilt not holding, wobble
Before you decide the arm is faulty, run through the five most common symptoms. Nearly all are fixed at the desk in minutes.
| Symptom | Likely cause | Fix |
|---|---|---|
| 1. Screen drifts down slowly | Monitor heavier than the tension you set, or over the arm's rating | Tighten the tension screw in small turns. Check the monitor's real weight (without its stand) against the arm's spec |
| 2. Screen springs up, won't stay low | Monitor lighter than the tension, or under the arm's minimum | Loosen the tension. If it still floats, choose a lighter-range arm such as the Easy HAS (0–8 kg) |
| 3. Tilt won't hold, screen nods | Tilt joint screw loose | Tighten the screw at the joint behind the VESA plate |
| 4. Whole arm wobbles when you type | Clamp loose, or desk too thin or soft | Re-torque the clamp. On a thin or glass desk, add the Reinforcement Plate (฿390) to spread the clamp load |
| 5. Creaks when you move it | Normal in the first weeks | Check every screw is tight. If the noise stays and the screen stops holding, see the next section |
Rows 1 and 2 account for nearly every "monitor arm not holding" complaint. The classic mistake is using the weight on the box, which includes the original stand — only the panel's weight counts once it is on an arm. Our guide to finding your monitor's real weight walks through it.
How to adjust monitor arm tension so the screen stays put
One rule: adjust in small steps, with the monitor mounted. The spring balances the actual load, so turning the screw on an empty arm tells you nothing.
- Mount the monitor and tighten every joint first; tension is the last thing you set.
- Turn the screw half a turn to one turn at a time, then lift and lower the screen to test.
- Screen sinks → add tension. Screen floats → reduce it. The sweet spot is light to lift, light to push down, and still when released.
- On a Twin arm, set each arm separately — two monitors rarely weigh the same.
- For a curved screen, allow about 20% weight headroom: its centre of mass sits forward of the VESA plate.
For very large, heavy screens, a heavy-duty arm such as the HYPERION has a tension-adjustable spring head made for heavy monitors. First install? See how to install a monitor arm yourself.
Signs the gas spring has really failed
Once you have ruled out rows 1–5 above, look for these signs.
- The monitor is inside the rated range and the tension is at maximum, yet the screen still sinks.
- Holding force fades over days — it holds today and needs re-adjusting within the week.
- Visible oil or grease seeping from the cylinder or around the joints.
- A sudden loss of force — an arm that held normally drops to the bottom of its travel.
If any of these apply, don't keep forcing the screw. Take the monitor off the arm for safety and start a warranty claim.
What to do if it has failed
The ERGONOZ ZEN-0, ZIMPLEX, HYPERION and TRAZER V2 arms carry a 3-year warranty. A claim takes two steps.
- Register the product on the warranty registration page.
- Contact the shop with your order number and a short photo or video of the symptom — a clip of the screen drifting after you let go, say. Video lets the team tell at once whether it is a setup issue or a part to replace.
Frequently asked questions
My monitor arm drifts down slowly — is it broken?
Usually not — the tension is set lower than the monitor's weight. Add tension in small turns with the monitor mounted, and check the panel's weight (without stand) is within the arm's rating.
How many turns of the tension screw do I need?
There is no fixed number — it depends on the monitor. Turn half a turn to one turn, test, and repeat until the screen moves lightly and stays where you leave it.
My monitor is very light and won't stay low. What now?
Reduce the tension to minimum first. If it still floats, the monitor is under the arm's minimum weight; choose an arm made for light screens, such as the Easy HAS rated 0–8 kg.
The whole arm wobbles on my thin particleboard desk.
Re-torque the clamp and fit the ฿390 Reinforcement Plate between the clamp and the desk. It spreads the clamp load on thin or glass desks.
Is a creaking arm a problem?
In the first few weeks it is normal. Re-check every screw. If the creak persists and the screen starts drifting as well, contact the shop.
The bottom line
A sagging, springing or drifting monitor arm is almost always fixed by checking the monitor's weight against the spec and adjusting tension in small steps with the screen mounted. If it still sinks, loses force over days or shows oil, that is a real failure — and ZEN-0, ZIMPLEX, HYPERION and TRAZER V2 are covered for 3 years. See every arm with its weight range in the Monitor Arms collection — orders over ฿800 ship free in Thailand.
Reader code: enter ERGONOZWELCOME15 at checkout on shop.ergonoz.com for 15% off your whole order (one use per customer).
About ERGONOZ — a Thai ergonomics brand designing monitor arms, standing desks, and ergonomic chairs for the way you actually work. Read the brand story at ergonoz.com.