PDP-11/45 RSTS/E boot problem

I got a laugh out of this anecdote. Of course, folks heard me chuckle and I tried to share the joke but.... Way too geeky for public consumption. Back in 2000-ish, I was upgrading my DG MV4000/dc to 8mb so as to be able to run the snazzy AOS/VS II tapes I'd got along with the 9 track drive I hacked onto the machine... The install would start and then bomb at a certain point every time. I decided to work the machine hard and then pull the board and give a good SNIFF. This is a 15x15 inch board populated with 256kx1 drams. The time in the machine got the board cooking nicely, and when I smelled a certain charred smell in the vicinity of a 74ls04, I knew it was that magic black smoke. I pulled a 74HCT04 from a known-good isa card, socketed the spot and viola! Working 8mb board. It isn't ALLWAYS the most expensive chip, thank God, and sometimes even us not- as-bright guys come off with a win. I really enjoy reading this list even though I don't contribute all that often or anything of much value. It is a pleasure to watch you guys work. Jeff On Thu, 2019-02-14 at 12:00 -0600, cctalk-request at classiccmp.org wrote: traced the failing path on the schematics. When Jim Newport the field service engineer showed up, Josh described the diagnostics result that pointed at the failed path, and added "This is the failed chip" (pointing to one particular chip. Jim asked "Why that one?" Josh answered "because that is the most expensive chip". It turned out he was right. paul