Search found 212 matches
- Fri Aug 14, 2020 2:49 am
- Forum: Welcome Area
- Topic: Hello from Texas Again
- Replies: 6
- Views: 7504
Re: Hello from Texas Again
Glad to see you back gammaray. We were worried about you. Good health to you my friend.
- Mon Jun 29, 2020 3:06 am
- Forum: Hardware
- Topic: Does Anyone Recognize This Pattern?
- Replies: 19
- Views: 22553
Re: Does Anyone Recognize This Pattern?
The problem with the keyboard turned out to be the ever-more-quickly failing ULA I was using in the unit. It will alternately accept input in the "J" column (for LOAD), or in the far column (for Shift-P double quotes, and Enter), but never both on the same boot-up. Stymied. The one good ULA I own, d...
- Sun Jun 28, 2020 9:54 am
- Forum: Hardware
- Topic: Does Anyone Recognize This Pattern?
- Replies: 19
- Views: 22553
Re: Does Anyone Recognize This Pattern?
Awesome post as always Mark. I had not heard of bugs in digital multimeters before. It caught me out completely. I replaced every component of the -5V circuit, and when that didn't work I pulled all 8 4116's thinking there must be an internal short in the chips. It was only when the bare board STILL...
- Fri Jun 26, 2020 10:17 pm
- Forum: Hardware
- Topic: Does Anyone Recognize This Pattern?
- Replies: 19
- Views: 22553
Re: Does Anyone Recognize This Pattern?
A lot has happened since I last posted to this thread. I'll try to review as I go so that any interested reader need not go back to re-read the previous posts. Mark and others had generously offered some great advice to assist me in attempting to revive an old Spectrum 48K I discovered in my possess...
- Sat May 02, 2020 11:52 pm
- Forum: Hardware
- Topic: ZX Spectrum + : no boot
- Replies: 32
- Views: 19116
Re: ZX Spectrum + : no boot
I just found a neat resource here: http://hardware.speccy.org/reparar-i.html. It would suggest C44 from comparison with your picture. You did a complete recap, but maybe there's still a fault there, or you got a bad part? I don't know.
- Thu Mar 12, 2020 9:24 pm
- Forum: Hardware
- Topic: Does Anyone Recognize This Pattern?
- Replies: 19
- Views: 22553
Re: Does Anyone Recognize This Pattern?
Sorry for the delayed response. Life tends to get in the way of working on this. And I think it's time to give it up. More on that presently. To answer the specific questions and areas of concern first, yes either the heat sink was fitted for testing, or a clamp-on auxiliary was used and power-ups l...
- Fri Mar 06, 2020 9:18 am
- Forum: Hardware
- Topic: Does Anyone Recognize This Pattern?
- Replies: 19
- Views: 22553
Re: Does Anyone Recognize This Pattern?
Is this progress? It certainly is different,... Soooo, I got the 2nd vLA82 in the mail, and had no real issues replacing the socket and putting it in. But rather than the crisp black and white stripes I had (if only briefly) before, this is what I get now: 20200306_014724.jpg The image is blurry--th...
- Sun Feb 09, 2020 1:22 pm
- Forum: Hardware
- Topic: Does Anyone Recognize This Pattern?
- Replies: 19
- Views: 22553
Re: Does Anyone Recognize This Pattern?
Yep, noise is what I had. But also at ULA 32, so the replacement ULA has been killed. Not sure how the computer and I managed to do that, but after some generous support from Charles, I have a second vLA82 on its way through the post. Efforts to revive this computer will have to wait for the mail sy...
- Fri Feb 07, 2020 5:04 pm
- Forum: Hardware
- Topic: Does Anyone Recognize This Pattern?
- Replies: 19
- Views: 22553
Re: Does Anyone Recognize This Pattern?
Yeah I was afraid of that. Pretty much wraps it up--I've no clock whatsoever on ULA 32 or CPU 6. ...She's dead, Jim.
The ULA had been working, but suddenly quit. Could a failing capacitor in the -5V power circuit do that?
The ULA had been working, but suddenly quit. Could a failing capacitor in the -5V power circuit do that?
- Fri Feb 07, 2020 9:22 am
- Forum: Hardware
- Topic: Does Anyone Recognize This Pattern?
- Replies: 19
- Views: 22553
Re: Does Anyone Recognize This Pattern?
Sorry for the triple post. I'm slowly learning to use this o'scope, like when to ignore "noise" zoomed in to look like something its not. Also looking at my ZX81 as an experimental "control" to give me some idea of what I should be seeing when I look at the Spectrum. I think I've clock problems. The...