BenQ TK700 vs TK705i: 705i needs no lamp replacements, and USB video requires compatibility

Check these before you buy

• Make sure your selection is the exact US TK700 or TK705i, and check which accessories come with it. The TK700ST, TK700STi and TK705STi are different models. Seeing a stand, mount, spare lamp or streaming bundle on a related listing does not mean yours includes one. Look at the current seller, condition and return terms. Nothing on this page asserts a current price, availability or delivery date.
• The TK700 needs either a compatible HDMI output or an adapter that explicitly supports your laptop and the signal you intend to send. Check resolution, refresh rate, audio and any copy-protection requirements along the entire route. Its USB Type-A port supplies power and cannot stand in for an HDMI video connection. A generic FAQ that mentions direct USB-C does not match the connector map of this exact model.
• To use direct USB-C video on the TK705i, begin by confirming DP Alt Mode in the laptop’s documentation. Then use a certified USB-C 3.0 video cable, plug it into the projector’s USB-C port and select that source. Enable the laptop’s external display if that is needed. Among the USB-C PC timings in the manual is 1920 by 1080 at 60 Hz. Verify the exact mode you want instead of inferring it from the connector name or the projector’s 4K label.
• USB-C power delivery on the TK705i works only when the included projector power adapter is used. The listed profiles are 5 V at 2 A, 9 V at 2 A, 12 V at 1.5 A and 15 V at 2 A, so the largest product of voltage and current is 30 W. The connected device has to support USB power-delivery charging. If you buy a cable separately, it must be USB-IF-certified and full-featured for power delivery as well as meeting the video requirement. Compatibility is not guaranteed. When the laptop needs more power to run or start up, use its own charger.
• Treat video compatibility and audio compatibility as separate questions. The USB-C section of the TK705i manual lists two-channel LPCM audio at specified sample rates, so do not assume that every surround format travels over USB-C. Some computer HDMI outputs send no audio at all and need a separate supported audio connection. The TK705i’s Bluetooth-headphone instructions cover its Google TV source only, which means they say nothing about Bluetooth sound from a connected laptop or HDMI console.
• The TK700’s lamp gets dimmer as it is used. The manual’s dedicated replacement section is marked for service personnel only, and it tells you to contact the dealer or BenQ when a replacement message or LIGHT warning shows up. The general safety section does call the lamp user-serviceable, but this comparison follows the stricter replacement instruction and does not recommend that you open the lamp cover yourself. Once the final lamp warning appears, the lamp must be replaced before normal operation can continue. If you will use it frequently, ask before buying about exact replacement-part availability, service cost and turnaround.
• The TK705i has an LED light source. According to its maintenance section, the lens needs cleaning and any failure goes to the dealer or service center. Do not take parts off, and do not assume the light source is a module you can replace yourself. Having no lamp to replace does not take away dust, cooling needs, electronics faults or the possibility of professional service.
• Wait until the projector is switched off and fully cooled before cleaning either lens. When dirt or dust is visible, follow the lens-cleaning method in its manual, using suitable lens paper, or a soft cloth with lens cleaner for smears. Stay away from abrasive pads and volatile solvents. Shut the TK700 down properly and unplug it before you clean the case. Occasional cleaning is not the same thing as scheduled lamp replacement.
• The TK700’s US page lists 4,000 hours in Normal, 10,000 in ECO, 8,000 in SmartEco and 15,000 in LampSave, while the TK705i lists 20,000 in Normal and 30,000 in Eco. Those are manufacturer light-source ratings that depend on the mode. They are not guaranteed failure dates, a warranted lifespan for the whole projector or a count of years without trouble. The TK700’s ECO setting lowers brightness, and its equivalent lamp-hour counter weights the different modes. Neither published life rating tells you what your eventual repair cost will be.
• To check throw ratio, measure from the lens to the screen and divide by the image width. The TK700 spans 1.127 to 1.46 and the TK705i spans 1.0 to 1.3. Rely on the image-size table and height diagram for your exact model, and test the real projection before you install anything permanently. A table needs a stable, level surface with separate room for the chassis and cable bends. Both manuals call for at least 50 cm from walls and free airflow. A confined cabinet is not made suitable by an optical match or by digital keystone.
• If you want a lower-latency gaming setup, read the mode instructions for your exact model. The TK700 calls for zero keystone, Auto Vertical Keystone off and Aspect Auto. On the TK705i, Gaming Boost applies in RPG, FPS, HDR RPG or HDR FPS modes over HDMI or USB-C, resets keystone to zero and requires perpendicular placement. Its ALLM instructions are for HDMI. Automatic geometry correction does not go together with a lowest-lag promise. We make no measured latency comparison here.
• When one particular high-refresh mode is essential, hold off on this purchase until BenQ confirms the exact resolution, input, source and firmware. The US page and the manual for the TK705i disagree on scan range, and a broad range does not amount to a list of supported timings. This comparison settles neither a 60 Hz ceiling nor 120 Hz support for the TK705i, and it does not pick the TK700 as a workaround for high refresh.
• Compare the current total for the exact condition and package, counting any HDMI adapter, video cable, streamer and mounting equipment you need. Add taxes and delivery where they apply. The TK700’s QS01 streamer is optional. The TK705i’s Google TV still takes setup, a suitable network and any app accounts or subscriptions required. A lower upfront total does not prove a lower total cost of ownership once lamp service and repairs come into the picture.