OK I am having a bad day!

[CraigsBar]

well few days actually

My JustCPC128k has died.... No keyboard input and the characters on the screen are garbled - That s broken, at least I do not have to case it now!

but more importantly

my CPC 6128 no longer reads any discs in either A: or B: drives. I have tried multiple 3inch, 3.5inch drives and an HxC. The all have the same problem.

"Drive A: disc missing

Retry, Ignore or Cancel"

any suggestions on where to start. I have an Just CPC 128k for donor parts....

Craig

[00WReX]

Hi Craig,

Maybe the FDC (Floppy Disc Controller) has crapped it.

Naming on the IC will be something like...ZILOG  Z765A usually has FDC written on it as well.

Is the internal floppy and a floppy connected via the external FD connector both failing ?

If you had both (JustCPC128 and normal 6128) fail within days of each other, obviously could be coincidence, but...

Are you using the same power supply, maybe an overvoltage is killing things...?

Cheers,
Shane

[CraigsBar]

Hi Craig,

Maybe the FDC (Floppy Disc Controller) has crapped it.

Naming on the IC will be something like...ZILOG  Z765A usually has FDC written on it as well.

Is the internal floppy and a floppy connected via the external FD connector both failing ?

Cheers,
Shane

Hi shane, yes both drives, no matter what combination are forever reporting disc missing.

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[CraigsBar]

OK Progress.

In relation to the JustCPC128 I have wiggles and reseated every IC on the board and it now works... sort of...

Colour and character display is now correct, and the joypad input works

So this leave the keyboard as non responsive at all

And that is driven by the only Non Socketed IC on the board (U28) which hides under the AY.

I guess this has failed but being Surface mount and hidden under the AY there is no way I have the skils to replace it (Even if Piotr were to send me a replacement)

So....

Assuming I can safely cannibalise this board for parts  is it worth cutting the legs on the FDC in the CPC 6128 and rigging up the NEC FDC from the Just CPC128 to test whilst waiting for a proper socket?

Is the NEC D765AC2 even pin compatible with the Zilog original in the CPC?

As removal of that IC for my soldering skills will result in leg cutting as it has too many leg for me to consider removing cleanly (I do not want to lift a trace on the CPC) what are the chances of this being at fault over something else on the board.

Thoughts please.

Craig

[CraigsBar]

Or Option B....

Post the whole thing to @Bryce for repair and more expense at the postoffices in Ireland and Germany!!

Craig

[Duke]

Or Option B....

Post the whole thing to @Bryce for repair and more expense at the postoffices in Ireland and Germany!!

Craig

I vote Option B, don't cut any legs. It probably isn't that bad and both can be fixed.

[gerald]

The Floppy controller is not directly connected to the drives. There are a set of output and input buffer (IC202 to IC204). On of them could be damaged.
So better not touch the 765 before checking these 

[Bryce]

The Floppy controller is not directly connected to the drives. There are a set of output and input buffer (IC202 to IC204). On of them could be damaged.
So better not touch the 765 before checking these 

I'm with Gerald on this. It's much more likely that one of the TTL buffers has failed than the FDC chip itself.

Bryce.... Expecting post from Ireland any day now

[freemac]

Ready signal has to be shunt while using 3.5 floppy drives... If not, it is displaying "not ready".


http://www.cpcwiki.eu/index.php/Guide_on_how_to_connect_a_3.5%22_drive_to_a_CPC6128/664

[CraigsBar]

Ready signal has to be shunt while using 3.5 floppy drives... If not, it is displaying "not ready".


http://www.cpcwiki.eu/index.php/Guide_on_how_to_connect_a_3.5%22_drive_to_a_CPC6128/664

All my drives (3, 3.5 or HxC) have genuine ready signals so that has nothing to do with it 😉

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[Bryce]

Or Option B....

Post the whole thing to @Bryce for repair and more expense at the postoffices in Ireland and Germany!!

Craig

Why have I been humming the "Postman Pat" theme music for a few days now?.... I wonder. 

Bryce.

[CraigsBar]

It's not packed let alone posted yet.

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[Bryce]

Just for info, send me a PM and let me know what you're sending. For the 6128 I just need the PCB. You can send me the JustCPC too if you like, although I'm not a big fan of repairing other peoples hardware developments.

Bryce.

[CraigsBar]

I am pretty sure the just cpc is dead. As everything works except the ps2 keyboard and that is would need a replacement from piotr. It'll be the cpc board, I'll remove the the ABBA and reset switches from the case and pack them too. It also has an STS copy mod fitted.

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[Bryce]

The PS/2 keyboard section of the JustCPC is the circuit that Gerald designed. It's an AVR µP. Either the firmware is shot or the µP itself has died. I can try to reflash it and if that doesn't work I would swap the µP and reflash the new one.

Bryce.

[CraigsBar]

The PS/2 keyboard section of the JustCPC is the circuit that Gerald designed. It's an AVR µP. Either the firmware is shot or the µP itself has died. I can try to reflash it and if that doesn't work I would swap the µP and reflash the new one.

Bryce.

Sounds like you are talking yourself (and me) into this.. 5v conversion at the same time perhaps?

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[CraigsBar]

Why have I been humming the "Postman Pat" theme music for a few days now?.... I wonder. 

Bryce.

And oddly the last 3 post men that have serviced my house have been Pat, Padraig and Patrick. It seems to be a requirement for my sorting office.

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[Bryce]

Sounds like you are talking yourself (and me) into this.. 5v conversion at the same time perhaps?

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5V conversion shouldn't be a problem either.

Bryce.