PSA: That time a control board fried mid-shift at the St. Louis Medical Center

Was swapping a VVVF drive on a MRL elevator at the medical center last Tuesday when the main control board sparked and died on me mid-test. Has anyone else dealt with sudden board failures on older Otis models, or did I just get unlucky with a bad batch?

3 comments

3 Comments

jessica_hall491mo ago

Actually it was probably a bad capacitor not a full "bad batch" issue. Those older Otis boards from the mid 90s had known problems with the electrolytic capacitors drying out after about 10-12 years. Had a similar blowout on a 1998 model last spring at a nursing home. The cap let go and took out a couple of the driver transistors with it. If you pull that board and see any bulging tops or crusty brown stuff around the base of the caps that's your culprit right there.

kim6931mo ago

Oh man, that exact same thing happened to me on an Otis model from the 90s. Fried mid-test too, no warning at all.

rubyk861mo ago

Bad batch or just the universe telling us all electronics are secretly out to get us.