S3a 512kB upgrade
Updating your old Psion S3a with only 256kB of memory to 512kB is fairly easy!
All one has to do is to solder in the two missing SRAM chips. The chips
are easy to get from any electronic parts dealer.
The possible types are:
Those chips are all SMD (surface mounted device). If you want to upgrade you
have to have good soldering experience or know one who has. The chips have
half pitch, i.e. pins are (middle to middle) 1.25mm away from each other. That
kind of tight but managable. Here in Germany Simons Elektronik was a good
source for them. I paid 61,40DM inclusive postage and packing. Compared to
199,00DM Psion wants for the upgrade I think it is fair :)
- Static RAM, 128k*8, 100ns (or less), LP SOP32
- Sony CXK581000M-12LB (those were in my S3a originally)
Opening the Psion
First of all backup your data! You will definitely loose all
data on your Psion during the follwing process and will be lost without a
backup! You should also try to wear a grounded antistatic wristwrap during
procedure in order to protect your Psion from an electro static shock.
Let's go! Close the S3a and open the SSD B drive bay and remove the backup
battery. Then remove the main batteries and leave the battery cover off. Then
open both drive bays and remove the two screws in there. One may be hidden
under the void warrenty label :) You will loose your warrenty
now ... Now open the S3a again. Now it becomes tricky. You will have to remove
the keyboard holding cover now. The cover is snapped into the main case and
you have to bend the main case a bit in order to snap it out. The two 'snaps'
are at the front of the cover beneath the space key. pull the main case back a
bit and try to pull the keyboard cover out. Be careful here in order not to
break it! Now carefully remove the whole cover. This is tricky too, because
the back left and right edges refuse to come out easily. After that you should
see the naked keyboard rubber with the keys on top. Unless you want to
reassemble the keyboard (I do not recommend this) try to pull down the whole
thing onto something flat like a piece of thicker paper or so. And here you are
with the mainboard! Now remove the four screws in the battery compartment and
remove the battery holder. Attention! The batteries are connected through two
thin cables and a plug with the mainboard! Remove the plug carefully and pull
out the cable.
Removing the mainboard
This is mostly easy.
The mainboard is connected to a smaller board underneath it with removable
connectors. The smaller board contains the speaker and both connectors for
the SSDs. Take a small screwdriver and carefully pull the mainboard out. Start
in the middle of the case (same position as for the keyboard cover). Do not
bend the mainboard too hard! At some point it should just snap out a bit.
The difficult part now is to remove the mainboard from the case. The connector
for the serial interface at the upper left edge still holds the board. Get
the screwdriver again and push it in a bit; hold it there. Now carefully
remove the board. There are no wires connected to it so you should have the
plain board in hands now.
Ever had a look at it?
Turn the mainboard over and have a closer look at your Psion! You should now
see a fat quad-pack chip on the right (that's the main Psion ASIC with most
of your Psion in it :) some other part in the middle and some chips on the
left. The leftmost chip(s) is the ROM chip. The german version does not have
the builtin spell checker so there are two free ROM pads. The chips to right
are the SRAM chips and here we are! You should see two identical SRAMs with
two free pads to the right. Those are the free pads where your new memory will
Get your soldering iron!
Now the most difficult part. Have a closer look at the soldering pads
for the two new chips. Are they pre soldered as mine were? Then you have an
easy job now! If not you are at your own now, becasue mine were, sorry! Now
take one of the new chips and lay it on the board, on the pads. Be careful
with positioning the chips. They have to be in the same orientation like the two
already in there! Lay them exactly centered on the soldering pads. All pins
have to have close contact. Now get your soldering iron and first solder the
upper left and lower right pin to fix the chip on the board. Soldering should
be easy because you only have to heat the pins and press them on the pre
soldered pad. Do not press too hard or too long! Just as long as it it needs
to give good contact. Too long could burn your mainboard or destroy the
keyboard on the other side! Do this with all the pins and the second chip.
After soldering have a very close look at what you did. Are all contacts made?
All pins connected? None forgotten? No short circuit between two pins? Fine!
Just reverse order the above steps and you should be fine within five minutes
maximum. If everything is connected insert the main battery first and check
Does it work?
Open the Psion and press ESC. You should hear an immediate beep and then
nothing should happen for some time (approx. 20 seconds). After that the
Psion S3a logo should appear! Now check the free memory on the system screen
using the menu. You should have approx. 400kB free (or more) now!
OK. You have just upgraded your Psion! Congratulations!
Perhaps you want to have a look at another page on this topic from a friend of mine
But beware that I cannot guarantee anything for the above process! If you
crash your Psion I cannot be held responsible for anything. And you will void
your warrenty, remember!
© by Nils Faerber, Siegen 1996