DrBackhands
Student
I'm gonna go back to probing after the ER5911. It looks like it's trying to initialize but can't for some reason not related to the chip itself.
- Thread starter DrBackhands
- Start date
DrBackhands
Student
So it seems really strange to me that I get zero signal at pin 7 of the ER5911. I started poking around where it was going at 10C (pin 5) and found pin 1 there was disconnected from pin 1 of 9C, so there was no SEL signal. I fixed this, there was corrosion on the trace, but sadly nothing changed. So now I'm wondering, what is this "ERDY" signal anyway? Every other pin at 10C has a signal except 5, and they all at least seem right to me... Is there something about the signal I don't get? To get nothing on the probe seems very strange.
This ERDY pin is low when its performing a write operation which will only happen the once.
Expand your search to include the 74LS253 IC's. The outputs from these also connect to data lines D0 - D7. Its likely one of these data lines is causing your problem.
Expand your search to include the 74LS253 IC's. The outputs from these also connect to data lines D0 - D7. Its likely one of these data lines is causing your problem.
DrBackhands
Student
Thanks for checking in!
I had checked the data lines a few days prior, but everything seems normal to me. I'm not getting anything stuck high or low or any floating signals either, everything is giving some kind of pulse. But lemme take a second look at the 74LS253s and see if there's anything off. I'll probably have some time tonight. At any rate, this one has my a bit stumped now.
I had checked the data lines a few days prior, but everything seems normal to me. I'm not getting anything stuck high or low or any floating signals either, everything is giving some kind of pulse. But lemme take a second look at the 74LS253s and see if there's anything off. I'll probably have some time tonight. At any rate, this one has my a bit stumped now.
