Re: 2465 Project, story so far.


Ondrej Pavelka
 

Sorry, I just noticed, I'm not used to this groups IO thing.

On Fri, 5 Jun 2020, 23:31 Siggi, <siggi@...> wrote:

Hey Ondrej,

you're conflating threads here - this thread is about problems in a 2465
(no-B).

Siggi

On Fri, Jun 5, 2020 at 4:56 PM Ondrej Pavelka <info@...
wrote:

Hi,
I've been through the manual but it's for 2445 I'm not sure if it covers
the B as well.
It passes all the startup tests just fine so I need to find a way to
backup
the Dallas and transfer the contents over.
My programmer doenst support Dallas 1225Y but I think I'll make
conversion
board to 2764 EPROM. Just slight wiring change. What I am yet to figur
out
us how to transfer those contents to a new Dallas or to existing one with
new battery.


On Fri, 5 Jun 2020, 22:09 Andy Warner, <andyw@...> wrote:

Do you have the service manual ? It talks about the boot process and
where
things get stopped.

I was lucky enough not to lose my NVRAM contents before I was able to
recap
and capture the nvram contents.

As I remember it, failing the RAM test (which includes the NVRAM) stops
things very early in the blinky-light POST cycle.

The section of the service manual is kind of oblique, IMO, but once you
get
how they are trying to say things it gets better.

My scope had the GPIB option, and it failed a little while after my
recap,
so I just removed it, since I know I would never use it. If you have
any
options, I suggest trying to boot without them.

On Fri, Jun 5, 2020 at 2:55 PM <trogg58@...> wrote:

Hi all, another hopeful newbie on here, I found this site whilst
looking
for some clues to attempt repair a 2465. I have managed to get it
almost
back to life but now stuck, I wonder if anyone would be kind enough
to
point me in the right direction.
Here is some background info, I have had the scope for about 12
years,
but
not really had chance to use it, the magic smoke came out about 10
years
ago when I switched it on, it got put on the shelf due to lack of
time
and
left there. Now I have some time on my hands (due to being
furloughed)
I
decided to dig it out and try and repair it.
After opening it up I spotted that C1018 had popped and C1016 didn’t
look
good so replaced both. C1020, C1052 and C1020 also had seen better
days
so
swapped them too, looking at all the other caps no obvious leaks or
bulges
so reassembled and switched on, the CRT just about came to life and
then
the smoke came out again. This time it was C1130, so I decided to
re-cap
as
advised on this forum.
I have replaced all the usual electrolytics on both PSU boards, with
a
mix
of Nichicon and Panasonics, and the Rifa caps, rebuilt and hey
presto
all
the voltages are well within tolerance, ripple all good too, but …..
the
post test gets as far as lighting all the front panel led’s and they
stay
on, CRT comes up with a static bizarre display showing four groups of
1111
across the top and bottom a central vertical line of dots, a
horizontal
central line of four groups of 4 dots then a top right to bottom left
diagonal of four groups of 4 dots, (picture posted under 2465 strange
display) only focus and readout intensity controls on the front panel
work., pressing the Delta T or V have no effect.
I do believe that I am the first person to effect any repairs to this
scope as all screws are present and there are no signs of any “after
manufacture” soldering of tampering, so its hands up I think I have
done
it
in myself.
Anyone have any ideas where to go first?
Thanks in advance…
John Carter



--
Andy







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