Epson H389AI Auto Iris Assembly – Genuine Replacement for EB-C710X / C713X / C715X / C720XN
If your Epson EB‑C705W, C710X, C713X, C715X, or C720XN projector is showing a flickering image, sudden brightness shifts, a constant clicking or grinding noise from inside, or the picture is stuck at a fixed brightness level regardless of scene content – the auto iris assembly has likely failed. This genuine Epson H389AI auto iris unit is the exact replacement that restores proper dynamic contrast control.
It’s not a refurbished pull or a third‑party mechanism. Original Epson iris blades, factory‑calibrated stepper motor, and correct light aperture profile. The assembly is labelled H389AI – match it with your original before ordering.
ConditionNew, original Epson service part (not refurbished)
Alternative Names Auto Iris Mechanism, Dynamic Iris, Contrast Control Module
| Compatible Models | Epson EB‑C705W (WXGA), EB‑C710X (XGA), EB‑C713X (XGA), EB‑C715X (XGA), EB‑C720XN (XGA) – installation / education series |
|---|---|
| Part Number | H389AI |
| Component Type | Dynamic Auto Iris Assembly – Controls light output for improved black levels and contrast ratio |
| Installation | Requires optical engine access – moderate to advanced repair. The iris mounts directly in front of the light path, behind the lamp housing. |
| Common Failure Signs | • Rapid or erratic brightness flickering – the iris blades are stuck or the motor is failing • Clicking, grinding, or buzzing noise coming from inside the projector • Image stuck at maximum or minimum brightness – auto iris does not respond • Projector error code related to iris mechanism (blinking status lights) • Visible dark or light patches that move on the screen (misaligned blades) |
What the auto iris does – and why it fails
The auto iris is a mechanical assembly with thin metal blades that open and close to adjust light output in real time. When the scene is bright, the iris opens fully. When the scene is dark, the iris closes to improve black levels. This gives the projector better perceived contrast (typically from 2000:1 to 5000:1 or more).
After years of operation (especially in classrooms or meeting rooms where the projector runs 8+ hours daily), the stepper motor can wear out, the blades can warp from heat, or the gear train can strip. Common failure symptoms include:
- Flickering brightness – the iris opens and closes randomly or constantly oscillates.
- Clicking or grinding noise – the motor tries to move but the gear slips or the blades are stuck.
- No dynamic range – the iris stays fully open or fully closed, killing contrast or dimming the image.
- Error condition – the projector detects a motor stall and locks the iris, sometimes showing a blinking error code.
A non‑original or generic iris mechanism may have incorrect blade shape, different motor resistance, or improper mounting alignment – leading to inconsistent contrast or mechanical binding. This genuine H389AI assembly matches the original Epson optical path exactly, ensuring smooth, silent, and accurate iris control.
When to replace the auto iris vs. ignore it
If you never use the dynamic iris feature, you can sometimes disable it in the projector’s Image menu. However, if the iris is mechanically stuck halfway, it will still affect brightness and may cause noise. Replacing the H389AI assembly is the only permanent fix. Without a functioning auto iris, the projector loses its advertised contrast performance – the image will look flatter, especially in dark scenes.
Restore your EB‑C series projector – not the whole unit
Replacing the auto iris requires removing the top cover and the lamp housing. The iris assembly sits directly in the light path, usually secured by two screws and connected by a small flex cable. Swap the old unit for the new H389AI, and your projector’s dynamic contrast will work like new again – no more flickering, no more noise, and blacks as deep as the day the projector shipped.
Note: Before ordering, send us a photo of your original auto iris assembly showing the H389AI label. Some C‑series models use different iris revisions, and we can visually confirm compatibility.
