Unix pc 3b1 power supply board.
guy
that can help me?
Thank you.
DoN. Nichols
> Hi, I'm looking for a new psu board for my dead 3b1. Is there someone
> that can help me?
What went bad on it?
Often what the failure is is an overheated connection in the
power connector running to the system board. This can show up in two
ways:
1) Browned area on the orange connector where the overheated pin
was located. Sometimes nearly burnt through. If the latter,
it requires replacing the connector, not just the power supply.
2) Overheating of the same pins causes the solder to melt where
the pin is soldered to the PSU board. Look on the underside for
one (or more) of the row of power supply pins where they are
soldered to the board, looking for a frosted appearance. This is
a "cold solder" joint, and will connect poorly and continue to
overheat.
If you have this -- you can use a solder sucker to remove the
old solder (melt some fresh lead/tin solder into it to make it
flow well), then take a piece of solid copper wire (20 ga or
larger) and wrap it around the end of the pin and lay it along
the traces of printed circuit and flow fresh lead/tin solder to
make a clean solid joint. (The board may be burned directly
around the pin, so extending the connection to a new area of the
board with the copper wire will help significantly.
Be sure to use the old lead/tin electronic solder. The boards
are not made to take the extra heat needed for the modern
lead-free solders needed to comply with the ROHS (Reduction Of
Hazardous Substances) rules -- and the rest of the computer
won't comply anyway. :-)
You only need a replacement power supply if the proper output
voltages are no longer present. Since I was never able to find a
schematic for those power supplies, repair of the actual supply is more
difficult.
Spare boards are *very* rare.
Good Luck,
DoN.
--
Email: <dnic...@d-and-d.com> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
guy
repair.
I hope to be lucky and find a spare board...
Guido.
On 15 Apr, 06:42, "DoN. Nichols" <dnich...@d-and-d.com> wrote:
> Email: <dnich...@d-and-d.com> | Voice (all times): (703) 938-4564
guy
millimeters wires (5V 20A...) and now works well.
Now I need a little help with the software: 10 years ago I perform a
copy of the original software (foundation set, devel disks, tcp/ip
drivers, gss terminal and so on....) with the command dd if=/dev/
rfp021 of=name and put them to a cdr.
Unluckily the cdr is unreadable and the floppies was damaged from
moisture. Someone could send me via email the foundation set? is there
copyright problems ater 25 years if we share the original software?
Guido.
> > --- Black Holes are where God is dividing by zero ---- Nascondi testo citato
>
> - Mostra testo citato -
supervinx
I downloaded recently tons of sw for this beast. Let me look better abd
find the foundation set.
guy
I made some pics: during boot, with dos coprocessor board working,
working with ua gui.... I will upload on Picasa.
G.
supervinx
http://www.unixpc.org/floppies/
Base OS is under foundation folder ...
guy
supervinx
Do you speak italian ?
I downloaded the software but never installed it.
It has still the original setup, and I'd like to add something more.
I'd like some hints (and a mouse !)
My email is
supervinx _AT_ libero _DOT_ it
Thanks !
DoN. Nichols
> Thank you!
>
> Please, take a look here:
>
> http://picasaweb.google.it/guido.rizzo/3B1LivesAgain#
Congratulations!
I see one thing which needs to be fixed. In the photo ofthe
system board, on the left side you see a blue cylinder with a white
stripe near one end. That is where the coin cell (CR3052 IIRC) should
go, so the system remembers the time and date between boots. I see that
the date/time is being displayed as the first of January just after
midnight, which is what you get with a dead cell.
I *think* that the blue cylinder is someones replacement
battery, a different version.
My original one had a coin cell with solder tabs soldered
directly to the board. I replaced it with a clip mount for the CR3052
(common in other computers still) so I would never have to unsolder in
that area of the board again.
Speaking of soldering, it looks to me as though someone has made
one of the modifications (ICUS or other similar ones which allow
extended disk drive access) (look at the red and white wires in the
upper left corner) and perhaps replaced the WD1010 hard disk controller
chip with a WD2010 to allow access to larger disk drives. (Since your
list of drives includes the Maxtor 190 MB drive, and the system during
boot says "3.51" instead of "3.0...3.5" (or whatever it used to say), at
least some of the mods are in place. In particular, the ones which add
another head select line, though I don't know whether there is also the
other mod which allows a second disk drive).
Enjoy,
DoN.
--
Email: <dnic...@d-and-d.com> | Voice (all times): (703) 938-4564
guy
guy75 AT libero DOT it
Due italiani con il 3B1, pensavo di essere solo...
Guido.