18 Jan
2004
18 Jan
'04
5:15 p.m.
They are
indeed 4116s, my comment on the glue gun was there
because 3/4 of
In which case you can check the +5V, +12V and -5V rails at pins on the
RAM chips. well, I'm still with the same
problem.....fortunately I saw smoke before
anything nasty happened!
And from where did this (magic) smoke come? You do, of course, realise
that it's smoke that makes electronic devices work -- when the smoke
comes out they stop working.
rails. In other words, you only need to check the
voltages at one of the
RAM chips (assuming there are no cracked tracks on the mainboard, but I
wouldn't worry abnot that yet!).
OK, so far we have +5V, clock signal and active address and data lines, or at least my probe makes the expected noises once I
found somewhere to get a
good 5V supply from, so I'd say the CPU is running and I have a problem
after that. Normally at this point I'd go for video RAM, but the only
obvious culprits for that are a pair of 6116s that live on the other
6116s are normally darn reliable.
If those _are_ the video RAMs, are you getting activity on their address
and data lines? In other words, is the video timing chain running.
What, if anything, do you get on the screen?
-tony