BenQ TH671ST

BenQ TH671ST: lamp-based short-throw projection

Assess presentations, video, and demonstrations with a screen close to the projector, planning geometry, content, and sound as a package.

Model and application

GLMedia has added the BenQ TH671ST to its equipment. Ask about availability and configuration for your date. It is a lamp-based Full HD short-throw projector; preparation and maintenance differ from an ultra-short-throw laser model.

Signal and optics

Image: 1920 × 1080 pixels; 16:9 aspect ratio and specified brightness of 3000 ANSI lumens. Usable size depends on light, screen, and content.
Optics: Throw ratio 0.69–0.83:1; 1.2× optical zoom and manual focus. Measure distance from the lens and check the manual’s table.
Connections: HDMI for digital sources and audio connections; USB-A power and service USB are not general video inputs.

System preparation

Record date, venue, audience, screen, and available distance; start with photos and approximate measurements if drawings are not ready.
Check placement and height using the optical table and a flat surface. Adjust zoom and focus before digital correction.
Test the actual computer and content, including small text, video, and audio; then introduce intermediate devices.
Allow shutdown and cooling time under the manual before handling or packing. Check lamp condition and history during technical preparation.

Planning questions

When might it suit a show or conference?
Is it the same as an ultra-short-throw laser projector?
Do lumens establish audience capacity or screen size?
What if text is sharp at the bottom but blurry at the top?
What changes because it uses a lamp?
What can I hire, and what information should I send first?

When might it suit a show or conference?

It can be assessed for a presentation or demonstration requiring the screen relatively close to the projector. We check size, walking routes, and light falling on the surface. If content is unreadable or placement unsuitable, we can compare another projection system, a display, or LED.

Is it the same as an ultra-short-throw laser projector?

No. This model uses a lamp and short-throw optics with zoom; ultra-short throw needs different installation geometry. We compare both using image width and available depth, rather than housing size or the word short alone.

Do lumens establish audience capacity or screen size?

There is no direct conversion. We need back-row distance, text size, screen, and ambient light. Options include controlling light, changing size, simplifying content, or another technology. Test the intended presentation in the image mode that will be used.

What if text is sharp at the bottom but blurry at the top?

First compare the internal pattern with the source and check screen flatness, alignment, height, and focus. Avoid large digital correction to compensate for poor placement. If the pattern remains uneven with correct installation, request technical inspection; internal optics are not adjusted during an event.

What changes because it uses a lamp?

Check mode, lamp condition, ventilation, and shutdown. The hour counter helps maintenance but does not independently certify a unit’s condition or brightness. Replacement and counter reset follow the service procedure; they are not presented as a universal fault remedy.

What can I hire, and what information should I send first?

We can assess rental, a screen, installation, signal and audio configuration, and technical presentation support. Send the date, venue, audience, and approximate needs even before files are ready. Availability and accessories are confirmed for the proposal; adding the model does not reserve it.

Checks by symptom

Checks by symptom
No image	Check lens cover, powered source, selected input, and a known direct cable; check computer output before adding adapters.
Blurry image	Compare pattern and source, check focus and alignment; do not confuse small or scaled text with an optical fault.
Will not restart immediately	Check whether cooling is still underway and follow the manual. Avoid rapid power cycles or defeating protection.

Use and safety

Do not look into the beam and keep vents clear. Plan mounting and orientation under the manual, avoiding impact, cables in walking routes, and heat buildup.

Do not open or service a hot lamp. Inspection or replacement requires the model’s service procedure and qualified personnel.

Official documentation

Consulted October 23, 2026.