Well I discovered the problem. The extender arm that is engaged by the cartridge when it is inserted has been bent. (Perhaps someone tried to shove a cartridge in without the handle lifted.) Anyway, without a replacement part the TK50 is not going to work again. Strangely, I went into another pile and came up with another E4 rev TK50 that had a different problem thinking that I might get the piece I need. No such luck, the mechanisms are quite different. There must be a zillion ECOs on the TK50, I don't think any two out of 6 present are identical. Well I've got four working ones and two dead ones. Other than the leader grabber, what other parts might be good salvage? (The hulks will stay in my scrap pile but at least they are now 'down for the count.') --Chuck