10 May
1999
10 May
'99
1:15 p.m.
On 10 May 99 at 19:06, Tony Duell wrote:
You're a rotten guy Tony. Even if I'm not into fixing it right now
you're
going to force me into it. Be it henceforth be noticed that I L Walker
relinquish control over one H89 computer and offer it up into common
domaine. Take that guilt merchant !
(but I'll still save the tips, just in case )
ciao larry
lwalker(a)interlog.com
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First thing is
to see if the built-in video terminal works and go from
there. There is a simple cable running between the Terminal Logic Board and
the CPU Board which carries the RS-232 signal for communication. All my
Yes, but whatever the CPU board decides to send on its end of the cable,
the terminal logic board will still do _something_... If you're worried
about that, though, just pull out the cable (the 0.1" spacing one on the
disk drive side of the machine between the terminal logic board and the
CPU board).
Incidentally, the rule for taking one of these to bits is 'think what
order the options were added and remove the latest one first'. In other
words start by removing the disk drive and its screening can. Then remove
the daughterboards and their cables. Then the CPU board. And finally the
terminal logic board.
H/Z89 docs are buried somewhare in this danged
house as we've recently
moved. No time to sort and catagorize many things yet. It's gridlock almost
like the old house was :( Knowing our resident archivist, Tony Duell, I
bet he will have docs in his collection and could take it from here. If he
Hey, I'm not an archivist :-). I don't stick manuals on shelves never to
be seen again. My manuals are 'working manuals'. I read them. I use them...
But yes, I do seem to have accumulated a rediculous number of obscure
service manuals...
by chance doesn't have the docs at hand,
either someone else here could
I have the Z-90 hardware manual here. I am not sure what you call it, it
came with the machine, so I guess it's a user manual, but it's got full
schematics, etc and more info than some service manuals that I've seen.
My method of fixing this would be :
1) Check/repair the PSU on the main chassis (see yesterday's message for
details of voltages)
2) Check/repair PSU regulators on the terminal logic card so that is
getting the right voltages
3) Get the terminal logic card working well enough to give the Beep at
power-on. Then see if it is producing sync/video signals.
4) If necessary repair the monitor analogue board so that the screen
starts displaying things.
5) Then start sorting out the CPU board.
Let me know how you get on with the PSU tests...
-tony