Search found 8 matches
- Sun Feb 24, 2019 2:54 pm
- Forum: Hardware
- Topic: ZX+ lower ram diagnostic help
- Replies: 25
- Views: 7424
Re: ZX+ lower ram diagnostic help
Hi everyone, Sorry for the long time before coming back - it's been a hell if a month. Anyway - I tried disabling the upper ram by connecting pin 5 to the positive rail and powering up. And it didn't start up at all. It just became completely unresponsive. Powering up didn't work, resetting, nothing...
- Sun Jan 20, 2019 6:52 pm
- Forum: Hardware
- Topic: ZX+ lower ram diagnostic help
- Replies: 25
- Views: 7424
Re: ZX+ lower ram diagnostic help
Hey guys, thanks for the advice and feedback. I will try disabling first, then Desoldering. I just haven't had a chance to look at anything all week, it's been a busy one!
- Mon Jan 14, 2019 6:36 pm
- Forum: Hardware
- Topic: ZX+ lower ram diagnostic help
- Replies: 25
- Views: 7424
Re: ZX+ lower ram diagnostic help
Hey there, thanks for the reply. So, here is what happens when do the "new" command: https://drive.google.com/file/d/12Jdy4CrQRN6iYxSW4pEC4nOAmfFSMvTn/view?usp=drivesdk Then I get screens like this after every reset: https://i.postimg.cc/D8mhns3P/20190114-182402.jpg But if i disconnect the...
- Sun Jan 13, 2019 12:40 pm
- Forum: Hardware
- Topic: ZX+ lower ram diagnostic help
- Replies: 25
- Views: 7424
Re: ZX+ lower ram diagnostic help
Hi guys, again - thanks for all the help. So I replaced IC11 and it's done something! https://i.postimg.cc/0bZrF770/20190113-115919.jpg The vertical red lines against black are gone and instead we have this pink striping thing! You can see the copyright message, though and it responds to key presses...
- Sat Jan 12, 2019 1:45 pm
- Forum: Hardware
- Topic: ZX+ lower ram diagnostic help
- Replies: 25
- Views: 7424
Re: ZX+ lower ram diagnostic help
Hi Mark I've checked everything over again. The board is a 1983 issue 4s. Unfortunately I don't have any test gear but I can probably knock together an oscilloscope or something. When powering up, it's identical every time. Border is white, and the screen is black with alternating solid and dashed t...
- Sun Jan 06, 2019 11:37 am
- Forum: Hardware
- Topic: ZX+ lower ram diagnostic help
- Replies: 25
- Views: 7424
Re: ZX+ lower ram diagnostic help
Hi again - thanks for the input. I've checked the voltage lines. All -5v pins are reading -4.86v which seems within range. All +5v pins are reading +4.94v All +12v pins are reading +11.82v The voltages are all stable, with none of the chips running hotter than any others. In fact, no single componen...
- Sun Jan 06, 2019 10:53 am
- Forum: Hardware
- Topic: ZX+ lower ram diagnostic help
- Replies: 25
- Views: 7424
Re: ZX+ lower ram diagnostic help
Thanks Mark. I'll check the voltage today and see what might be going on!
- Sat Jan 05, 2019 12:47 pm
- Forum: Hardware
- Topic: ZX+ lower ram diagnostic help
- Replies: 25
- Views: 7424
ZX+ lower ram diagnostic help
Hello everyone. I was given a ZX+ for Christmas which worked for a little while, managed to get a few round of Jet Set Willy and Dizzy in before it just crapped out on me. See the image for the issue I'm having. I've looked around online and discovered that it could be a lower ram issue. Im a compet...