Original Tandy 1000 no boot

[falter]

Yeah the tops of some of the legs of the ICs have some surface rust, but the legs themselves seem to be fine and same with sockets where applicable. Hopefully the two controller chips get here soon and maybe that ends it there.

[blackepyon]

Can I confirm that the first chip you replaced, the 74LS32, is U98 and not U58? U58 is half way across the board from this circuit, next to the main oscillator.

[falter]

Yes it was u98.. closer to the FDC.

[blackepyon]

Alright, about where was the trace that got damaged initially, and what was it connected to?

[falter]

Okay so I got a replacement FDC9216 (or was it 8216) chip, and it boots! Fantastic! Thought I could finally put this together, get it off my bench and carry on with my play space renovation.

Buuut..

Now the keyboard doesn't work. The num and caps lock keys don't light if you press them, and when it finishes booting, if the keyboard is plugged in it starts going nuts producing random junk. Ugh! I don't think anything I was working on was in the vicinity of the keyboard circuit.. at least, going by the schematics. Hmmmm

[blackepyon]

It's 2020. Nothing is simple anymore
At least the floppy is working now.

[falter]

Interesting.

I had a last minute thought. I swapped the old FDC chip back in. Drive stopped working, but keyboard worked! Wha...

Luckily I bought 2 FDC chips.. plugged the other one in.. now it all works... weird.

[blackepyon]

That's interesting. I don't see any obvious relationship between the two other than the data bus. But the floppy was booting, so the bus is obviously working. I hope here isn't an intermittent crack in the board somewhere.

But hey, everything's working now! Maybe 2020 isn't a total loss after all?