Zx80 blank screen
Zx80 blank screen
I bought this with no modulator, put one in, I have blank white screen with no cursor. Checked chips V in all had 5 volts.Ic 2 slightly warm but not excessive. Any ideas. This is issue 2.
- 1024MAK
- Posts: 5165
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Zx80 blank screen
Typically this is a fault with one of the two SRAM chips. But there are other possible causes, including the ROM, the Z80A, or some of the smaller chips.
Can you please post up a photo of the board.
What test gear do you have?
Mark
Can you please post up a photo of the board.
What test gear do you have?
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
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 being good this year.
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
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 being good this year.
Re: Zx80 blank screen
I have a multimeter. Sorry for delay on getting back to you. I think I've attached a photo.
- 1024MAK
- Posts: 5165
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Zx80 blank screen
To attach a photo, use the Attachments tab below the text box, or if using a PC with modern browser that allows drag and drop, drag a photo file to the text editor box window.
Mark
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
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 being good this year.
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
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 being good this year.