Lamp error / won't turn on on the BenQ TH685

Source: ProductDB new-categories research catalog Confidence: 90% Verified Aug 8, 2026

The projector shows a lamp error or fails to turn on, often from a worn lamp, a faulty lamp door or a blocked filter.

How to fix Lamp error / won't turn on

Check the lamp door and filter

Ensure the lamp door is fully closed and clean the air filter to prevent overheating.

Source: ProductDB new-categories research catalog Confidence: 80% Verified Aug 8, 2026

Difficulty: ★ Est. 5 min

Replace the lamp

If the lamp has reached end of life, replace it with a genuine spare.

Source: ProductDB new-categories research catalog Confidence: 80% Verified Aug 8, 2026

Difficulty: ★★ Est. 15 min

Replacement parts for the BenQ TH685

BenQ TH685 Replacement Lamp BenQ TH685 Air Filter BenQ TH685 Remote Control BenQ TH685 Power Supply BenQ TH685 Replacement Lens

← All BenQ TH685 error codes

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