PC-9821Nr15

This thing has seen better days for sure, with its yellowed keyboard and weird sound oddities.

Cheat sheet

Sleep + Power switch = Hard shutdown
The pinout is triangular, but only two pins are used: The top pin is ground, the bottom left pin is +19VDC. Bottom right is NC

Disassembly

ACHTUNG: This section is written based on memory. The number of screws might be wrong but the general idea should stand the practical test. NO REFUNDS, DOUBLECHECK YOUR WORK.
If you are the proud new owner of a Nr15 you might want to take it apart for inspection, as you would with any old computer. Even if you aren't the guy who checks his old JPCs before turning them on, it is a very good idea to have a look anyway.
If you're having some issues you might want to look later into the page before reading this section to have an idea on where to stop.

  1. Start with the laptop facing up, now flip it to show the bottom side, optimally with the bottom stickers being the correct side tobe read
  2. Remove all cards from the PCMCIA slot, any external cable, until all you're left with is the laptop itself
  3. Hold the lock slider in the unlock position with one hand, and pull the release tab in the middle to let go of the bay contents. It might be stiff but shouldnt take too much force
  4. Take out the battery door and the battery by sliding it right
  5. Take out one small screw on top of the hard disk door, then the hard disk door by sliding it left
  6. Slide out the HDD caddy by pulling it towards you, then take off the gray plastic interposer's screw
  7. If your model is a S14F: carefully take out the modem from its ZIF socket on the top
  8. If your model is a S10: remove the gray screw covering the modem port stub, then said modem stub
  9. Take out all the screws you can find (should be four small in the battery door, two left in the hard drive door, 4 big ones at the very top near the hinge)
  10. If you hear the I/O bay doors give up a little, you're on the right track. Flip the laptop up-ways and open the lid (carefully)
  11. Slide sideways both speaker holes to release the keyboard
  12. Lift the keyboard paying attention to the ribbon cable near the bottom

    13. You have access to the System Memory sockets now. Feel free to inspect them or replace them if that is what you need. If you want to, take them out.

  13. Unplug the ribbon cable of the keyboard in the center, then the trackpad's under it, then the speakers' on the top left
  14. Take out two long screws in the center and one short screw on the side (Place them separately, as they are a different length)
  15. Carefully checking again that you did, in fact, unplug the trackpad ribbon cable and the speaker wires, lift the top up
  16. Unplug the display connector on the top left of the motherboard. Different models have different colors, so note the orientation

    17. You now have access to the following components: Status LCD, Power Switch plastic piece, Sound Mixer Board, IR Port, Backup Battery, Suspend Battery. If you have not yet taken the suspend battery out and you are unsure of its age, TAKE IT OUT as it is prone to leaking very destructively.
    If this is all you needed, you may follow the steps in reverse to reassemble the laptop. Make sure it still turns on, the CPU board is sensitive. If it still turns on, feel free to bail out by following the instructions in reverse. Otherwise...

  17. Unplug the Status LCD, and place aside the power switch plastic piece
  18. Unscrew two screws, one at the bottom left over a metal piece and one on the top right. Do not bother with the small ones on the top left.
  19. Slide out then rotate north the metal piece to free it
  20. Unplug the IR ribbon on the bottom right part of the motherboard
  21. Unplug the Sound Mixer Board ribbon, then carefully lift up the board itself from its ZIF socket
  22. With a plastic tool get some leverage to lift up the top left part of the motherboard, then as soon as you feel it give, lift it up in one move, as there are two connectors in the top left and center of the motherboard that plug into the I/O board at the bottom

    23. You now have access to the I/O board and the CPU board (on the bottom side of the motherboard).
    If you have no business with the CPU board, be sure not to dare looking at it wrong, as it is known to have weak connections. If you are done, this is your chance to bail out, otherwise...

  23. Take out the four plastic or metallic legs on which the motherboard rests on from the I/O board
  24. If you didnt before, this is a good time to reach under the laptop to remove whatever is in the bay
  25. Remove 6? screws and the PCMCIA plastic slot frame
  26. Lift up the I/O board

    27. You now have eviscerated your laptop of every motherboard piece. Congratulations! There is nothing to see now. Feel free to carefully check the pinouts you are unsure of or the power regulator circuit.

Troubleshooting

MEMORY ERROR on boot: Reseat RAM sticks, check power input, check power rails
No video, no pipo, no nothing but Poweron led: Check CPU board connection, check power rails
PCMCIA not detecting cards properly / slot needs servicing: Follow disassembly up to step 18, Unscrew the small screws, flip the motherboard and slowly lift up the PCMCIA cage
Some software doesnt run at all and freezes! (e.g. all Touhou) / I get no audio! (e.g. Flame Zapper Kotsujin) (86 Sound Source is detected on YAHDI): This model requires CanBe patches/workarounds, so if you arent using them be sure to try again taking that into consideration. YAHDI users need to also edit the launcher.
I get no audio! (No 86 sound source is detected) / I get no audio! (86 Sound Source is Detected but volume control doesnt show CD-DA) / WSS ADPCM only works sometimes!: There is an issue with the Sound Mixer Board's connector towards the motherboard being weak. You might have to reflow them, follow the disassembly up to step 21.

Gallery


Soon?