ZXmore or the ZX80CORE follow-up

[Becky]

Soldering the ZXmore kit had being going well up until I tried to solder C4. A lapse in concentration somehow screwed it up big time, including destroying the metal collar in one of the mounting holes. Will connecting the capacitor directly from R18 to the output of D11 fix it?

Cheers,
Becky.

[1024MAK]

Soldering the ZXmore kit had being going well up until I tried to solder C4. A lapse in concentration somehow screwed it up big time, including destroying the metal collar in one of the mounting holes. Will connecting the capacitor directly from R18 to the output of D11 fix it?

Maybe. One leg of capacitor C4 (470pF) does indeed go to R18 (100k), the other leg goes to various places according to the schematic: IC11 (74HC590) pin 10, D11 (BAT42 or BAT46) cathode, IC26 (Altera EPM3064) pin 40.

My old eyes cannot see and follow how the PCB track gets from C4 or D11 to/from IC11 pin 10 or IC26 pin 40 (I am normally good at this, but because PokeMon has used a nice white solder mask, it does make track tracing difficult).

So you need to use a multimeter (a digital meter on the continuity/low resistance range) to confirm that any damaged PCB track(s) and plated through holes either work, or have been repaired by running wires to replace any breaks. If the wire to "jump" the break is very short, use a cut-off wire from a component. Or strip the insulation from a thin solid core wire. Otherwise use insulated wire (0.5mm dia copper core or smaller) solid core wire.

I hope that helps.

Mark

[1024MAK]

ALTERA EPM3064A PLCC pin-out.png (41.06 KiB) Viewed 3838 times

Taken from the datasheet.

Mark

[PokeMon]

Soldering the ZXmore kit had being going well up until I tried to solder C4. A lapse in concentration somehow screwed it up big time, including destroying the metal collar in one of the mounting holes. Will connecting the capacitor directly from R18 to the output of D11 fix it?

Cheers,
Becky.

C4 isn't that important and used to separate the DC part of the MIC (out) signal.
As long as you don't need to use SAVE over the cassette recorder you may leave this space empty as well.
Probably you would like to SAVE over the USB flash drive more than over a cassette recorder.
This is a nostalgic gimmick only.

Clipboard04.jpg (63.76 KiB) Viewed 3831 times

One side goes to R18.
The other is connected to VSYNC (vertical sync pulse) which is available at following points:
IC26, pin 40
IC11, pin 10
D11, cathode side

You may download the schematic as well which was uploaded in this thread some posts earlier.

[olofsen]

One more ZXmore is running After, indeed a second optical inspection, so now I know what happens if Z80's /RD is not connected Thank you PokeMon, the construction manual is perfect!

[PokeMon]

Cool - thanks for the feedback.
I am still working on the next release - so in about 10 days you can expect it.
Don't know if all could be realised what was planned in time but then I will publish an intermediate release.

[Becky]

Not quite alive yet:



It's not running properly, but powers up and no chips are running hot. Any ideas guys?

[Paul]

I have no idea what the problem might be, but I do like the pattern.
If the problem is solved we might be able to make a jumper to get this pattern

[PokeMon]

It's not running properly, but powers up and no chips are running hot. Any ideas guys?

Did you check the solder joints and jumper settings ?
Did you solder the connection between IC23 pin 9 and 10 and the two capacitors at the solder side of the board ?

[Becky]

It all looks okay, but I just realised that R11 has not been placed! Maybe once I do that it might help.

Cheers.