Inside

This page describes in detail how to disassemble a Psion Serie 3a palmtop, illustrated with many pictures.
Disassembling a Psion can make sense for example if you want to upgrade your 128k or 1MB Psion to 256k, respectively 2MB for less money than Psion charges. or you maybe want to fix problems like a defective battery cable or even dead display lines without having to send the computer in for repair.

Almost all pictures on this page are scaled down versions for not to increase loading times even more. If you want to have a closer look at any picture just click on it to download the original version.

Instructions to disassemble a Psion Series 5 cant be found at the moment, it seems. (There was one, once!). If you know of one, mail me!

Legal Mumbo-Jumbo:
The contents of this page are copyrighted and may not be copied or reprinted without written permission of the author.

Disassembling a Psion Series 3a

CAUTION: Disassembling a Psion palmtop is not easy at some points and you will need some experience and knowledge. If you should damage or destroy your Psion while following these instructions I can be in NO WAY held responsible for this or any other direct or indirect consequences.

required tools (minimum):
• 1 Cross head 'philips' screwdriver size #1-2
• 1 watch-maker's screwdriver with ca 2 mm, very thin blade

recommendet tools:
• 1 wide (paint-)brush (10-20) for careful cleaning the inner parts
• 1 anti-static wrist wrap for servicing purposes
• 1 pair of tweezers
• 1 soft, antistatic cloth to put the Motherboard on

PART A: DISASSEMBLING

Backup


ALL DATA IN YOUR PSION WILL BE LOST IN THE COURSE OF FOLLOWING THESE INSTRUCTIONS! PLEASE DO A BACKUP FIRST BEFORE CONTINUEING!

Opening the case

• Remove the battery cover. Take out the batteries.
• Open SSD slot B. Press the lithium cell slightly at the edge with your finger nail towards the speaker, the lift it up and take it out. Put it somewhere on a dry, nonconducting surface.
• Remove the thin sticker in SSD slot A using the small screwdriver. ATTENTION: Any WARRANTIES WILL BE VOID when this sticker is removed!!
• Remove the screw beneath the sticker with the cross head screwdriver as well as its counterpart in slot B and the 4 screws in the battery hold at the back of the unit below the batteries. Put all screws aside as part XS1.
• Close the slots and drag the battery compartment slightly to the back a bit. Do not jerk! The power supply cable is stuck behind a hook at the left with a piece of rubber, it has to be lifted out there carefully. Now remove the cable at the plug with care and put the Battery case aside as part XS2.

Please note:
when closing the Psion the button bar will easily cant, because it is bent upwards by the power of the hinge springs. For that reason, please do not close the unit until the battery compartment is put in place again. If you intend to have the unit open for a longer period (more than 30 minutes) it is recommended to put the battery compartment back in place and fix it using one of the screws XS1, to free the button bar from the (rather high) spring pressure.

Removing the Keyboard cover

• look for a small recess at the right front of the keyboard, well right besides the rubber pad. The cover can easily be lifted from there *slightly*. DO NOT JERK! Use the recess as a starting point and lift the cover about 1 - 2 mm max. There is a second recess right of the left rubber pad.
• You will notice that the cover can be lifted relatively easy towards the corners of the case as opposed to the center part at the space bar where it is still very fix. The reason are two hooks at the front edge of the cover, approximately at the ends of the round recess in the Psion case that is there to ease the opening of the unit during normal operation.
• Now use the small screw driver or your finger nails to work carefully from the corners of the Psion case between the case and the keyboard cover towards the center of the space bar. Try not to scratch the case. When you have reached the hooks use the small blade (your finger nail will break!) to carefully lever up the keyboard cover. PLEASE dont stick in the blade too deep between the cover and the case! You can easily damage the motherboard!
• After you have lifted both hooks carefully you can easily lift up the keyboard cover at the center and raise it up front. Then take it out slanted to the up front and put it aside as part XS3.

Removing the keyboard


• You are now looking at the keys on their rubber pad
• If in doubt, jot down which key is at which place.
• With some skill you can pick the rupper pad at the edges and put it aside with all keys still lying on it as part XS4. Please avoid touching the contact pads with bare fingers. You can put the cover (XS3) over the rubber pad to hold the keys in place.

Removing the motherboard


• Please put on the wrist wrap to protect the motherboard against static electricity, else you may damage the unit.
• The motherboard is backside up. On its (invisible) front it is connected to a daughterboard below via two plug bridges in the center area.
• To loosen the connection lever the mortherboard *carefully* in the region of the space bar and slightly right of there (with the small screwdriver, like the keyboard cover) and loosen the plugs by constantly wobbling it up and down.
• now lift the motherboard up at the front edge until it is slanted then carefully drag the left back edge out from under the screen hinge.
• Now drag the right back edge out the same way. It may happen that the closure mechanism of the serial port cants. With the small screwdriver you can press it up carefully through the hole of the serial port, so that it will no longer get stuck at the edge below in front of the hinge.

In the zoomed image the RAM chips are easily found. If two of the four soldering pads for the chips are not occupied, the RAM can be internally expanded to twice the amount available. (This applies for the 256k and 1 MB Models currently)
With some soldering experience the two other chips can easily be put onto the PCB because of the relatively wide pin spacing of about 1 mm.
The chips shown are from a 1 MB Model and cost about $150 (in Germany).

The other free sockets below the OS ROM Chip at the very right are the ROM sockets for the spellchecker and thesaurus dictionaries which are not occupied in the german models. Funny enough that although they are missing, the german Psions are much more expensive than the UK models.

Removing the shielding metal


• Unscrew the right one of the two screws on the daughterboard with the cross head screwdriver and put it aside as part XS5.
• Take out the metal and put it away as part XS6.

Unplugging the foil cables


• On the daughter board there are two mountings for the foil cables of the display (yellow) and the button bar (blue).
• At the mounting for the blue cable you can see two sightly darker nipples. Pull them to the back carefully by using the small screwdriver. After approx. 2mm the cable is loose and can easily be pulled out of the mounting. Be careful not to touch the cable contacts with your bare fingers. Do *NOT* isolate the contacts against touching by using any kind of adhesive tape!

  Tip:
  If you have problems with your button bar, it might help to loosen the cable and fix it in a slightly different position.

• The display connector can be loosened using the same principle but you should pull the clamp nipples to the front instead of pushing them.

  Tip:
  If you have problems with your Display, it might help to loosen the cable and fix it in a slightly different position.

Removing the daughter board

• Unscrew the screw at the left front edge of the daughter board with the philips screw driver and put it aside as part XS7.
• Lift the board up at the front until it is in a slanted position then pull it out to the up front like the motherboard. Part XS8.

Going even further (to repair the Display f.e.)


• Close the lid. Bend the ends of the springs which are at the buttonbar slightly to the side and remove the tension by putting them onto the top of the lid carefully. Put a slip of paper between the spring ends and the lid, they are sharp and could damage the finish (see the picture: a blue piece of cardboard is used for this).
• Keeping the lid closed, try to find out which of the hinge nails is less tight and pull it out with the small screwdriver carefully.
• Unhinge the lid by pulling it to the side. Do NOT bend it, the hinge might break! If you are of the daring type you can remove the springs from the lid. Put the Display with the LCD side up and turn the spring ends up. You then should be able to pull them out by moving them towards the center of the lower edge of the lid. S ---> <--- S This is, however, not really necessary. (Parts XS8b)
• You are now able to remove the button bar by simply bending it a bit. (Part XS9)
• At the lower side of the lid, the one close to the button bar, begin to lift up the covering foil of the display *very*carefully*. Begin at the center of the lower side, lift it up slightly. DO NOT BUCKLE THE MATERIAL! When you have lifted up more of the foil you can carefully lift the rest by pulling it up in a low angle. Most of the adhesive should remain at the foil if you do it right. Put the foil with the adhesive side up and place it somewhere wher you cannot accidentally put your hand or elbow or whatever on top of it. (Do you have a cat? This might end hairy.) Part XS10.
• At the right side of the display there is a small black piece of plastic visible now. It is clamped between the lid and the display. Drag this piece to the lower side of the display. Now it should be loose. Put it aside as part XS11.
• Now carefully push the whole display at the left edge to the right of the lid, until the right edge is where the piece of plastic formerly was. then you should be able to simply pull up the display at the top left corner and take it out of the lid.

Trying to repair a defective Display column


• It is easy to see that the display connectors are at the top and left of the display. My specific display problem was solved by putting a very small piece of rubber into the fold of contact foil between the display PCB and the display itself. I cut a tiny piece out of a simple rubber gum with a surgery knife and pushed it into the small opening at the left top side extemely carefully with a simple paper clip from my desk.
• To reach that opening I had to remove the plastic clip from the left side of the display PCB. It is fixed with two small pins sticking up from the lower side of the pcb into two small holes. It is easy to see, you just have to press the pins down with something and drag the clip sideways.
• If you have problems with a defective display row or column, try to find out the exact problem area by creafully "brushing" over the connector foil (only squeeze very slightly) until you see the missing pixels appear. This is the right position to apply one of those magic rubber pads as described above :-)





REASSEMBLING

Assembling the display


• Please take care not to forget to push the display back to the left and fix it with the plastic pin. The pin must be put in, so that the small nipple at the side is at the bottom left and it goes through the little notch in the circuit board of the display. Then push the pin to the top side of the display until everything seems to be securely fixed.
• If you removed the springs it is the right moment now to put them back in. Take care and dont let their ends scratch the top of the lid.
• Make the foil fit as accurately as you can before you let any area of it go down to the surface of the display. Removing it again and again does no good to it.
• Brush the foil at the edge of the display from the center to the corners to fix it. Do not apply pressure to the foil at the upper or side edges of the lid! You will squash it in (ugly!).
• Do not forget to put the button bar back in before you rehinge the lid. Put the foil cables of the bar and the display correctly through the opening below the bar without buckling it. Dont touch the contacts of the foil cables with your bare fingers.
• Rehinge the lid, put the second hinge nail back and put the springs back into the notches in of button bar.

Putting the daughter board back in

• Put the daughterboard XS8 back in like you removed it - slanted from the upper front into the notches at the back of the case - then turn it down carefully until it is lying plain.
• Screw in the screw XS7 at the left front corner of the board.

  NOTE:
  Screw them screws in without any violence! If you are too rude you will destroy their plastic sockets!

Reconnecting the foil cables

• Again: dont touch the contacts with bare fingers.
• Take the yellow cable of the display and bend it down until its end points to the back of the case. !!Do not buckle!!
• Now put the end of the cable into the rear socket while shaking it slightly until it goes no further.
• Fix it by pressing the darker coloured, frontmost part of the socket at the left and right side to the back until it clicks into place.
• Now take the blue button bar cable and put it into the front socket, using the same method.

Putting back the shielding metal

• Hold the metal so that the connection at the middle is in front and the spikes at the left and right front corners point up.
• Fix the metal with screw XS5 at the right front of the daughter board.

Tip:
use two small pieces of double sided adhesive tape beneath the left and right edges of the metal to avoid the "cheap" rattling of the Psion when no cards are inserted in the slots.

Putting the motherboard back in

• Make sure that you are protected against static electricity by using a wristwrap or a similar device. Dont touch the keyboard contacts with your bare fingers.
• Hold the motherboard at the edges, component side down so that the protruding edges are pointing to the button bar.
• Insert the board slanted from the up front, the edges right below both hinges. If the mechanics of the serial connector get stuck at the shielding metal on the left side, carefully guide it over the edge with one of the screwdrivers.
• Put some cloth or a piece of paper on top of the board, then press it down with slight, even pressure until it clicks into the sockets of the daughter board below. Press it slightly down at the edges of the casing, too, because it tends to cant.

Inserting the keyboard

• Please dont touch the keyboard contacts with your bare skin.
• Take the rubber pad XS4 of the keys at the edges and put it on the motherboard, the space key pointing to you.
• Adjust the rubber, so that the two small rubber pads at the front fit into the notches at of the casing.
• Make sure that all keys are on the rubber and in the right place.

Placing the keyboard cover

• Hold the keyboard cover XS3 so that the hole for the space bar is in the right position and insert it hooked below the hinges, just like the motherboard.
• DON'T press it down with violence but pull the middle of the cover upwards slightly (at the back edge) while you carefully turn it down until it touches the keys.
• Make sure that no keys are stuck below the cover.
• Press down the two small hooks in front of the space bar with a small screwdriver or your fingernails until they are going into place with an audible click.

Closing the case

• Close the lid. CAUTION: Due to the spring tension the button bar might be protuding and canting when you close the lid. Just press it back slightly while you close the lid.
• Insert the small connector of the battery case XS2 into the socket at the left hinge of the Psion.

  ATTENTION:
  NO VIOLENCE! The connector is designed in a way that you normally cannot plug it in wrongly. If it does not seem to fit just turn it by 180 deg and retry.

• Push the cable with the safety rubber behind the small tip left of the battery cable socket.
• Apply the battery case to the back of the Psion (watch not to sqeeze th cable) and fix it using fours screws XS1. (Not too tight!)
• Open the SSD lids and apply the remaining two screws to their sockets near the lid hinges.

Now put all the batteries back in and everything should be fine!