Excellent pointers on how to keep the original style IBMs working. Its amazing how reliable and long lasting the originals have been, (made in the USA)? But going back to my post, I've personally never had to replace a yellow jacket replacement (after ten years on some jobs) or whatever they call the replacements now. Yes, you can't meter the pins, but they do have have the handy coil energized L.E.D. Great thread.