I have a broken pinball motherboard here that I'm trying to fix. I'm using a Fluke to spy on the data bus because it has a line stuck high. Connected to the data bus there appears to be: 1 EPROM 1 RAM 1 Resistor pack A couple of 74HC244's bringing in the switches matrix data A load of 74AC374's driving the transistor-controlled outputs I've isolated the EPROM, RAM and 244's from the circuit and it makes no difference. I don't really fancy removing all the 374's so I thought I'd ask if anyone knows whether the 374 IC would ever fail in a state where it would drive a bus line high from an input to that IC? I could understand an output from a 244 doing it but they have all been isolated. Do resistor packs die very often? Is there a better way of testing for a stuck bit other than snipping the pins of the ICs :-( The processor on the PCB is a 68000 and when I use the Fluke and 68000 pod to check the bus, it says it's OK, but every manual read from the databus gives a stuck bit. Has anyone ever seen the 68000 pod do this? TIA! Phillip Eaton If you ever want to (un)subscribe yourself with TTL, you can send mail to: <Majordomo@flippers.com> with the following command in the body of your email message: (un)subscribe techtoolslist or from another email account, besides xxx@yyy.com: (un)subscribe techtoolslist xxx@yyy.com