05-11-2013, 10:16 PM
Well there are two ways for BE to be open.
The most popular is, the junction is shot, so no current flows, so the CE has to be open. But then the C would be at full Vcc (9V) and not at zero.
Another way is, the bonding wire got detached but the junction is intact.
Then the junction is autobiased and the transistor gets to close, at which point the C goes to 0V or so.
Anyways that's not terribly important. It does look a bit like the Q3 has bought the farm and is actively pushing the daisies now.
The most popular is, the junction is shot, so no current flows, so the CE has to be open. But then the C would be at full Vcc (9V) and not at zero.
Another way is, the bonding wire got detached but the junction is intact.
Then the junction is autobiased and the transistor gets to close, at which point the C goes to 0V or so.
Anyways that's not terribly important. It does look a bit like the Q3 has bought the farm and is actively pushing the daisies now.
