Canon T90 repair & common faults
Excellent coverageThe Canon T90 is a 1986 flagship SLR from the last generation of Canon's manual-focus FD system, nicknamed 'the tank' for its sculpted, ergonomic body. It was Canon's most sophisticated FD camera, built around a microprocessor that runs a multi-pattern metering system and an electromagnetically controlled shutter, and most of its faults trace back to those two systems ageing.
Microprocessor-controlled electromagnetic vertical-travel focal-plane shutter · Multi-pattern SPC metering (spot, centre-weighted, averaging) · 4 × AA batteries · Canon FD breech-lock mount
Common Canon T90 faults
Canon T90 growling or grinding noise
A low growl or grinding sound from the mirror box, sometimes on wind-on and sometimes on firing, is the T90's best-known ailment. It points to the gear train that drives the mirror and shutter mechanism, where the original lubricant has thickened with age and is loading the motor. It rarely fixes itself and tends to worsen. Fresh batteries won't change the noise, so that's not a useful check here.
Canon T90 won't fire
A dead camera that won't respond to the shutter button, with no meter readout and no motor sound, is almost always electrical rather than mechanical. Worth trying a fresh set of four AA batteries first, since the T90 is unusually sensitive to weak or mismatched cells and to corrosion on the battery contacts. If the camera stays silent on good batteries, the fault sits deeper in the electronics.
Canon T90 LCD missing segments
Blank patches, missing digits or the whole top LCD panel going dark are a common age fault on this camera, caused by the display's connections degrading over time rather than the display itself failing outright. It's cosmetic in the sense that the camera can often still fire, but it makes shutter speed and mode confirmation unreliable. There's nothing to check without opening the camera.
Canon T90 exposures inconsistent or meter not reading
Frames coming back over or underexposed, or the viewfinder meter display flickering or not responding to light changes, points to the metering electronics or one of its sensors drifting out of calibration. Worth confirming the camera is in the metering mode you expect, since the T90's mode dial is easy to nudge, but a genuine drift needs proper measurement against a known exposure to confirm.
Canon T90 mirror stuck up
A mirror that stays up after firing, leaving the viewfinder dark, usually points to the same ageing mirror drive mechanism behind the camera's grinding noise, rather than a one-off jam. It can also follow from a battery that died mid-cycle. Try fresh batteries and a gentle wind-on first, since that occasionally releases it, but a mirror that sticks repeatedly needs the mechanism looked at properly.
Stuck on your Canon T90?
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Try it now ›Scatto is a reference tool for people who service film cameras. It explains mechanisms and quotes service data, but it cannot see your camera at the bench, so verify anything load-bearing before you act on it.