Hi All !
I started checking / replacing all the capacitors - tantalum and
electrolytic - on the CPU board saved from the US. Until now I don't
found the guilty.
The CPU board of the USA is a horror to troubleshoot, because of the
acid the battery that changed the nature of solder tin and some kind of
resin characteristic of these PCBs, it is difficult to desolder the
components. I wonder if I would do better to repair my own CPU board
because this one is finally in a better state in comparison.
What is raging is that these two types of breakdownswere perfectly well
identified by Sperry Univac. According to the UTS 20 manual :
- Blank screen and long tone (the breakdown of my CPU board) : I'm
supposed to report this information to my Sperry Univac customer
services, point, no explanation
- SERIAL I/O CHANNEL B failure (the breakdown of the CPU board from US) :
Their advice = Corrective action: none, and I'm supposed to transmit the
code "3560U-0010" (still to my Sperry Univac customer services).
Zero information, nothing, it is raging. One or two clues to orient my
research would be so precious...
I have the corresponding manual but for the UTS 40 somewhere lost in my
attic. I will find it, I do not have the hope to find a better
description but I must be sure.
On this subject, I would like to scan and share it because it does not
exist on the internet.
Dominique
On 2/10/2017 18:13, Dominique Carlier via cctalk wrote:
Hi everybody,
Here is the next episode of the restoration of my UTS 40.
During the previous “season”, I was talking about buying a wreck of an
UTS 40 from the USA.
http://www.zeltrax.com/classiccmp_forum/annonce.jpg
I had taken the risk to buy it, after the conclusion of the sale, the
seller had retracted, I had argued with him, I finally put a bad note
on Ebay. However, surprise! The guy still sends me the machine. This
one remains blocked during a full month at the Belgian custom house. I
finally receive it, and now, if you like horror movies, you will be
happy.
Here is the state in which I received the machine:
http://www.zeltrax.com/classiccmp_forum/uts40_from_usa_01.jpg
http://www.zeltrax.com/classiccmp_forum/uts40_from_usa_02.jpg
I never - never! - received a package in this condition !! The reason
maybe was the hideous and ridiculously “protective” packaging ?
Possible ... or in the plane they 400kg over my UTS ? Possible ... but
we still have the impression that someone hammered the machine, even
the very solid plastic pieces have also shattered.
As I am an optimistic guy, I think "the plastic ... not important,
fortunately the chassis and the electronics of this machine is build
like a tank".
I analyze the boards, as expected, some architectural differences but
not so much. Here is the CPU board:
http://www.zeltrax.com/classiccmp_forum/uts40_from_usa_03.jpg
http://www.zeltrax.com/classiccmp_forum/uts40_from_usa_06.jpg
Unsurprisingly, the battery has sunk and there are damages:
http://www.zeltrax.com/classiccmp_forum/uts40_from_usa_04.jpg
http://www.zeltrax.com/classiccmp_forum/uts40_from_usa_05.jpg
http://www.zeltrax.com/classiccmp_forum/uts40_from_usa_07.jpg
With courage I clean the board, I replace some resistors, one
capacitor, ...
Before/After
http://www.zeltrax.com/classiccmp_forum/uts40_from_usa_08.jpg
and I replace the battery (2,4V ? A doubt persist)
http://www.zeltrax.com/classiccmp_forum/uts40_from_usa_10.jpg
And comes the time of the first test and it boot!
http://www.zeltrax.com/classiccmp_forum/uts40_from_usa_09.jpg
http://www.zeltrax.com/classiccmp_forum/uts40_from_usa_09b.jpg
The POC test at startup is not successfull but from the outset, this
allows me to analyze and diagnose some elements of my own UTS 40, here
is what I notice:
- The program cartridge of my UTS 40 is functional
- The power supply to my UTS 40 is OK
- The video circuit of my UTS is OK
- The keyboard of my UTS requires a restoration (aluminum discs, foam
cylinder, classic issue of old keytronic keyboard)
http://www.zeltrax.com/classiccmp_forum/uts40_from_usa_11.jpg
http://www.zeltrax.com/classiccmp_forum/uts40_from_usa_12.jpg
- The absence of the backup battery is not a problem, the machine can
boot, without this it can successfully passing the POC test and the
encoding of the parameters in the setup page is possible.
I discover other interesting things about the relationship between the
cartridge program and the hardware configuration.
- These program cartridge are made for a specific hardware
configuration, for example the RAM repartitions at the level of
hardware has an impact on the result of the startup test. The number
of kilobytes checked, the memory extension considered as PASSED or
FAILED. Even the installed memory is working and assignable, with a
configuration that differs from the hardware intended to run with a
specific Program Cartridge, the POC test could show that a memory is
missing, simply because the RAM is not physically in the slot or
socket according to the program specification in the cartridge.
I drew this conclusion because the CPU board form USA has 64Kb
installed on it, and 27 empty sockets, I filled them with RAM and now
with the program cartridge form Ebay, 4X 64KB are detected and
flagged with a PASSED.
However with my program cartridge, it detects a second memory
extension as PASSED, but considers the first extension FAILED, I think
that on the original CPU board, there was only 32kb, even 16kb and
non-extensible on that board (hence the presence of two memory
expansion boards in my original configuration). Briefly, according to
the inserted program cartridge, the tests are sometimes but not always
dynamically adaptable to a given configuration.
- A cartridge program can be programmed to operate only with a
specific model of PERIPHERAL I/O board. The program cartridge form
Ebay does not work with my PERIPHERAL I/O board, however my program
cartridge seems to detect the PERIPHERAL I/O board of the US.
- I recreated the breakdown of my machine with the hardware of the
other UTS. I'm talking about the situation of a long BEEP + blank
screen, this happens if I remove the unique memory expansion board in
the original configuration of the UTS from Ebay, this could mean that
my own CPU board is maybe OK and that this could be one of two memory
extensions of my machine that has a problem (Hypothesis).
But now, without documentations, without diagrams and schematics,
without info, I'm blocked on a problem, at the beginning it was
intermittent, now it's constant, and even aggravated, the explanation:
Here is the best result I could get with the following configuration:
CPU board form US + my PERIPHERAL I / O board + memory extension from US
The POC test is successful, it loads the default settings in non
volatile RAM:
http://www.zeltrax.com/classiccmp_forum/uts40_screen01.jpg
And I can access the setup page:
http://www.zeltrax.com/classiccmp_forum/uts40_screen02.jpg
Everything would be perfectly fine if most of the time I did not have
at startup an error at line 9. of the POC test:
SERIAL I / O CHANNEL B: FAILED
http://www.zeltrax.com/classiccmp_forum/uts40_screen03.jpg
This error blocks the machine, it does not load the default settings,
I no longer have access to the setup page.
I continued to clean the board, looked for damage related to corrosion
of the CPU board because of the battery, but today it is not better,
it stops at line 8 of the POC TEST:
http://www.zeltrax.com/classiccmp_forum/uts40_screen04.jpg
However, it could be inferred that this is because the machine can no
longer determine whether the status of the SERIAL I / O CHANNEL B is
PASSED or FAILED.
Last thing, the few times I was able to go into the setup page, I
rushed to try to encode (with the dead keyboard) the information to
declare the subsystem and finally return to the CP/M mode. And I had
twice the fig case where busy to enter the data, without warning hop!
Blank screen, reset, POC TEST -> SERIAL I / O CHANNEL B: FAILED
We have here some interesting information about the intermittent
nature of the failure, could this give information about the type of
component in default?
So I have not yet been able to return to the CP/M mode.
My questions are:
- What exactly is "SERIAL I/O CHANNEL B" in this machine?
- What components are used by this SERIAL I/O CHANNEL B?
- Is there really no way to find the schematics of that CPU board? Or
better, the complete machine, including the PSU?
I think that if I can fix that problem, I could go back to the setup
page and restart the machine in CP/M mode, in fact it is the last
obstacle, if I solve this problem my machine is fixed.
Thanks in advance for your help !
Dominique
