The problem may reside in an electronic circuit that runs the strobe. This happened to me with my Denon DP80. In the DP80, there is a single IC that performs several functions necessary for full operation of the tt. One of them is to emit a signal of a fixed frequency that runs the strobe. If that circuit goes out, the strobe won't light up. It was a bit easier to find a replacement IC (from a vendor in Hong Kong) than to find a new strobe light, which thankfully I did not need. BTW, the DP80 ran OK even with the faulty IC in place, as your tt may also do.
