14 Dec
2010
14 Dec
'10
1:57 p.m.
Yes, there is always the possibility that his ROM or IWM is also faulty but
we'll see what happens.
The PSU "swapping" I was thinking of is that I'll trade him a working Lisa
PSU if he'll trade a working I/O board (that is assuming he HAS such a board
in the "spare boards" he mentions).
I actually took the working PSU in question apart last right and replaced
all six of the old filter capacitors. These are the ones I've found tend to
blow and smoke eventually.
Terry
I would think it's safe to put untested ICs into
your machine, but puting
anyting into a machine whioch could have PSU provlems seems to be a
little risky...
However, as (presuambly) you don;'t know these spare chips atr good, if
the machine still dcesn't work, you dont; know if the problems is
somewhere else entirely, or it is the ROM 9say), but you've not fitted a
good one.
and I have a
spare working one so some swapping might be on the cards
depending on what's there.
I thought the PSU schematics were available. A lot of faults could be
_rpeaired_, it's not that complex a supply (althogh SMPSUs are paerhaps
not that pleasant for beginners to work on, thay have a lot of live
circuitry ('live' as in 'directly connected to the mains), which will
giee you a very nasty shock (at best [1] if you do the wrong thing. Oh,
and making a mistake can also result in lots of expensive power
transistors failing.