Search found 5 matches

by ziggy123
Wed Aug 28, 2019 9:45 pm
Forum: Hardware
Topic: Issue 3 Spectrum 48k no display no boot nothing
Replies: 7
Views: 2467

Re: Issue 3 Spectrum 48k no display no boot nothing

No worries Mark, I was sidetracked myself ;-)
by ziggy123
Tue Aug 27, 2019 11:57 am
Forum: Hardware
Topic: Issue 3 Spectrum 48k no display no boot nothing
Replies: 7
Views: 2467

Re: Issue 3 Spectrum 48k no display no boot nothing

Mark I evenually got it working it was a faulty ULA, I got a Nebula from retroleum, working great, i also made a TZXDuino to load the games :-)
Many thanks for your help :-)
by ziggy123
Tue Jul 16, 2019 10:53 pm
Forum: Hardware
Topic: Issue 3 Spectrum 48k no display no boot nothing
Replies: 7
Views: 2467

Re: Issue 3 Spectrum 48k no display no boot nothing

Hi Mark, im back again... test signal on pin 32 of the ULA.. no signal, im just getting a high signal, the line goes to top then drops when i turn it off. I also tested using Saleae logic program but im getting an error on the 24MHz setting saying that it cant keep up with the data,(ive changed USB ...
by ziggy123
Tue Jul 16, 2019 2:41 pm
Forum: Hardware
Topic: Issue 3 Spectrum 48k no display no boot nothing
Replies: 7
Views: 2467

Re: Issue 3 Spectrum 48k no display no boot nothing

Thank you Mark for your help :-) I trust that your power adapter/PSU is set to the correct polarity? yes What are the actual voltages on the +5V +12V and -5V rails? +4.96V +11.98V -4.82V First, let’s look at the +5V and +12V supplies to the video section. Test pin 14 on the ULA (IC1) for the +5V sup...
by ziggy123
Mon Jul 15, 2019 10:12 pm
Forum: Hardware
Topic: Issue 3 Spectrum 48k no display no boot nothing
Replies: 7
Views: 2467

Issue 3 Spectrum 48k no display no boot nothing

Hi all, I picked up a untested Spectrum from ebay, hoping to relive some of my youth, I had a ZX81 back in the day and was always envious of my classmates when they got the speccy, I would appreciate if you guys could help me bring it back to life :-) Before I turned it on I followed JoulesperCoulom...