Panasonic FS-A1WSX: RAM upgrade problem

Pagina 1/3
| 2 | 3

Door Diode

Supporter (4)

afbeelding van Diode

18-05-2020, 22:28

I am new to these forums and still a bit of a novice when it comes to MSX computers, and so I'm sorry if this is a stupid question.

I have been trying to learn about electronics, and so I recently decided to upgrade the RAM of my FS-A1WSX computer. I am not very experienced, but I thought that I had practised enough to attempt the upgrade to 256KB (the 512KB upgrade is maybe still a little too ambitious). The instructions that I was trying to follow can be found here:

https://www.oboroc.com/posts/2004/05/09/panasonic-msx2plus-c...

Unfortunately, I was wrong to be so confident. I tried to be careful not to apply too much heat to the circuit board when removing the solder, but, to my horror, I found that the copper track had been lifted from the board in two places.

I have included evidence of my crimes against MSX hardware:

Naturally, I panicked, and I haven't been near it since, just in case my mere presence makes it even worse.

I suppose this issue is really just a general electronics problem, but I was wondering if someone with more knowledge of this particular computer would have a better idea of how to fix it. I have tried to find out how lifted traces would be fixed in general, but I'm not sure how I should apply these methods in this case.

Does anyone know if there is anything that I can do about this? Also, do you have any advice about how to prevent this from happening again?

Thanks for reading this. I would be very grateful for any assistance.

Aangemeld of registreer om reacties te plaatsen

Van Daemos

Paragon (1718)

afbeelding van Daemos

18-05-2020, 23:07

No worries. Happens all the time. DId the same to the same computer and the user who got it back is still happy with it Wink

Here is how to fix is. Strip a stranded copper wire and remove one strand. Now with a very fine sharp knife. Scratch open some of the remaining trace and apply some solder to the open trace. Then lay down the strand of wire and pull the rest off the wire through the open solder hole. Then place the new IC and solder the wire strand to it.

Seal the trace with some superglue in the end.

Practice first on a cheap print then do i for real.

Van Meits

Scribe (5850)

afbeelding van Meits

18-05-2020, 23:15

Daemos wrote:

No worries. Happens all the time. DId the same to the same computer and the user who got it back is still happy with it Wink

Was that a WSX or a WX?

Van Grauw

Ascended (9050)

afbeelding van Grauw

18-05-2020, 23:48

It can happen. Destructively cutting the chip’s legs can help to avoid lifting pads. Anyway just follow the trace to find a point it that you can solder on, and add a “bodge wire” (any regular little piece of wire) to connect the pin back to the board. Use a socket so that if the chip ever needs to come off again you don’t need to solder in that area anymore.

Van Daemos

Paragon (1718)

afbeelding van Daemos

18-05-2020, 23:50

Quote:

Was that a WSX or a WX?

Can't remember but it was a msx2+ missing some parts. Wink

Van Meits

Scribe (5850)

afbeelding van Meits

19-05-2020, 01:00

Ah, that was a WX. And it's still running like it was new.
Didn't even know it gave you a hard time... I'll spank it on your behalf.

Van Diode

Supporter (4)

afbeelding van Diode

19-05-2020, 13:24

Thank you for the advice.
I think that sounds sensible - I should see if I have anything that's a little more expendable to practise with and give that a go first. That should give me the chance to gain some confidence with it. It looks like it might be tricky to find a good trace to solder onto for the IC21 pin, though...
Using sockets sounds like a really good idea. I don't have any at the moment, but once I have some, that's what I'll do.

Van gdx

Prophet (3489)

afbeelding van gdx

19-05-2020, 13:40

To avoid this kind of problem, use flux, do not heat too long and hold the pad with the iron only when the pump sucks.

If you can't follow the track, take a look te pinout at the RAM Datasheet. It can help.

Van Meits

Scribe (5850)

afbeelding van Meits

19-05-2020, 15:21

To avoid this from happening to my ram expasion project to one of my machins I bought a desoldering station. You can't go much saver than that. It removes components leaving a clean, unharmed, as new PCB.
It's a little bit of an investment, but it's cheaper than buying a new MSX if you "kill" it.

Van Daemos

Paragon (1718)

afbeelding van Daemos

19-05-2020, 15:55

Diode,

Are you located in the netherlands. If you are not too far out I find it no problem to fix the machine for you.

Van Pentarou

Champion (257)

afbeelding van Pentarou

19-05-2020, 17:13

IC 21 Pin 5 is NC, so doesn't matter.
IC 24 Pin 1 is D0, just bridge it to IC 23 Pin 2.

Pagina 1/3
| 2 | 3