Moggy wrote: ↑Wed May 24, 2017 5:20 pm
In my case left the modulator in place and fitted the CCB (great picture) also you might want to fit one of these...
...it makes the whole shebang run a damn sight cooler, not sure where in the world you are so this link is for illustration only but I'm sure a local supplier will be at hand.
Followed your advice and refitted the UM1082 with its guts removed. Love the smell of old leaded solder CCB is in place now and I do see a signal on my scope, so moment of truth now... If I don't report back, my ZX80 is floating in a canal. Oh, I'm in the Netherlands btw.
Good idea about the step down converter. Was thinking of building one myself, but these things are cheaper than I thought!
IT IS ALIVE! Yesss... My first working ZX80 since 37 years Picture is a bit dark, but that may because I'm not using a CRT, but a modern LED TV. Tried tweaking the pots on the CCB, but that doesn't seem to help. Will check that later.
Pfew... But anyway... back to the original topic! Now I have a working model that I can compare my new PCBs against. They should arrive early June. I have ordered naked boards without solder mask. I thought all ZX80s were without, but this model has solder mask on the bottom. Maybe something they changed as well for the US market? I also noticed that it is an ISSUE 2, written in the top and bottom copper. But is says ISSUE 2A as a cut out in de solder mask.
My one (and only) ZX80 has a green solder mask on the underside of the PCB only.
On both sides, the copper layer has ISSUE 2 markings. The solder mask on the underside has ISSUE 2 just visible to the side of the edge-connector. The white silk screen printing on top also includes ISSUE 2.
Being a U.K. version, neither the top or the bottom case halfs have any metallic layer, and so there are no metal spring contacts anywhere.
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
1024MAK wrote: ↑Wed May 24, 2017 6:37 pm
My one (and only) ZX80 has a green solder mask on the underside of the PCB only.
On both sides, the copper layer has ISSUE 2 markings. The solder mask on the underside has ISSUE 2 just visible to the side of the edge-connector. The white silk screen printing on top also includes ISSUE 2.
Being a U.K. version, neither the top or the bottom case halfs have any metallic layer, and so there are no metal spring contacts anywhere. Mark
Thanks for the info. Maybe I'll add a solder mask to the next batch. Let's see if the layout is correct anyway. Not a big fan of magic smoke
Moggy wrote: ↑Wed May 24, 2017 10:26 pm
Another 80 back on the road, marvellous!!
Nice one Mafli.
Should be light picture even on modern TV keep experimenting.
Thanks Moggy! Really excited as it is the first ZX80 I ever owned.
And I got the screen working now. A little PEBKAC... But solved now. Rock solid!
Next step is to whiten the enclosure.
MaFli wrote: ↑Wed May 24, 2017 6:10 pm
IT IS ALIVE! Yesss... My first working ZX80 since 37 years Picture is a bit dark, but that may because I'm not using a CRT, but a modern LED TV. Tried tweaking the pots on the CCB, but that doesn't seem to help. Will check that later.
The ZX8-CCB was made to deliver 1Vss composite video signal at 75R as standard input impedance of the video device. There may be two reasons influencing the brightness. First a bad GND solder connection to the case - could be tested with a bypass cable. Or the video input has not 75R impedance (maybe higher) - this could be tested with a bypass resistor or checked with an oscilloscope the video level when the LCD is attached.
Anyway it is not recommended to connect both black cables to GND. The second is for convenience only when using a separate connector somewhere in the case. Otherwise you create a GND loop which may influence the brightness as well or give some distortions.
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
PokeMon wrote: ↑Sat May 27, 2017 10:40 pm
The ZX8-CCB was made to deliver 1Vss composite video signal at 75R as standard input impedance of the video device. There may be two reasons influencing the brightness...
Yes... got it working! Forgot to RTFM (Read The Fine Manual ) My fault... Probably going to order a few more from you. The new boards should arrive early June...
Yesss.... Got the boards today! Looking good so far. Although I made the slot in the edge connector a bit too wide. Will fix that in the next version. Still have to draw the top silk screen anyway. Time to assemble!
CCB is in place now and I do see a signal on my scope, so moment of truth now... If I don't report back, my ZX80 is floating in a canal. Oh, I'm in the Netherlands btw.
Standby alert 
