do ram chips break much?

[coppercone2]

I have to replace a TC5514P to trouble shoot my 4191A.

Is it likely that ram chips like this break? Do they have a bad reputation? I know modern computer ram is pretty shady.

I noticed one of the batteries was dead (0.4V, the other was 1.1V).

I read about those old logic chips possibly getting burn out when they get stuck on a voltage near some thresh hold. Is it common for them to go when batteries go? In this case it might have been running at 1/2 standby voltage for a long time. Some gate can get stuck in transition region on the chip and burn out?

Kind of like the problem when you have too much fan out, it says that can break some chips physically if signal is low. I thought maybe if power is like that it might not like it and stress something?

[fzabkar]

I replaced numerous SRAMs, DRAMs, and PROMs during the 1980s.

[coppercone2]

I don't like my odds because its 2020s

this unit was working but it was a little futzy sometimes, you needed to reset it sometimes. Maybe it was a sign of that ram going bad. 


Lol, I have the god damn calibration standards for this thing too. Failure is not a option. It was supposed to be my inroad to impedance understanding.

[fzabkar]

I don't like my odds because its 2020s

I'm looking at a datasheet dated 1985 ...

[coppercone2]

The first thing they need to build on mars is a semiconductor factory so they can replace their life support assy when it gives a e21


I like this machine though, it is fairly easy to work on like a pickup truck, I don't have elevated vital signs when I am thinking about doing a card level repair on it. Putting that PCB on the hood that lifts up is a brilliant idea. I wonder how many heart attacks that prevented.

[coppercone2]

ok its alive, wants CAL and gives the usual BS on startup, so it is as good as it was.

Maybe I can fix the god damn welder now, I made sure to leave the 4191A on my lab chair, so I don't work on anything else until I fix it. quite a obstacle


Replaced while board was in chassis using solder pump/wick, hot tweezers and careful soldering, because there was just way too little room to work on it lol

all those ceramic chips... makes me not wanna move the board, last thing I need is for it to slip and crack a ceramic component. I don't have 2x2 foot PCB holder (yet), makes me feel like a bum

I should get a nice heavy high quality artist ezel and put big boards on it ! Now that would be a good project!