Ouch! I managed to kill my only one timebase.
Probably inserting and extracting it with
the mainframe powered, now the 7B92A
doesnt trigger anymore, it triggered before :(
Fabio.
P.S. Yes I know, I shouldnt insert plugins
with the mainframe powered, also if the 7704A
manual tells that I can.
Fabio Eboli <fabioeb@...> ha scritto:
I'm still messing around with the 7704A.
Faulty parts:
Till now I found 3 shorted transistors in the
Z-axis board, for now I swapped them with normal
transistors, I will search better replacement
in future, the parts are Q4159 Q4183 Q4185.
I changed also Q4163 because it had a very low beta.
Also U2530 isnt working ok, it doesnt select B horizontal
timebase with the correct input combination.
In the diagram and measuring it, seem
that the output is high when pin 6 is at +1V,
and low when is slightly negative,am I correct?
The other faulty component is Q2577 with a beta of zero.
Q2577 and 2579 are selected parts, anyone knows what
are the selection criteria? Can I try to put in
normal npn transistors for now?
There is a little progress:
After replacing Q4159 Q4183 Q4185
I have the readout working on the screen,
also readout intensity regulation is ok.
The trace intensity regulation is still non
working. It remains very low, almost like
if the z-axis is blanking the screen.
Also I still dont have the sweep from the timebase.
When I use the TB in vertical bays it works, when I insert
into one of the 2 horizontal bays it doesnt generate the
sweep, but the horizontal position pot on the TB moves
the dot on the screen, so it's like the TB sweep is
disabled.
Fabio.
Fabio Eboli <fabioeb@...> ha scritto:
Oops, sorry I totally missed that.
I think I should read the manual before asking
such questions :)
Fabio.
Albert <aodiversen@...> ha scritto:
There is an extensive description of the U2530 Horizontal Binary
operation at page 2-15 manual.
Albert
anybody knows the function of the 155-0013-00 IC ?
---
Fabio.
----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.
----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.
----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.
