I will be glad to open mine up, and 'PhotoFact' it for you.
I can take scope shots of the critical signals, voltage rails. I suppose the first, would be if you hit the HOME PAGE key it should clear the screen, I can follow that signal path, and take some scope shots... Even with the screen flooded,if I let it sit and hit space, not HOME PAGE on my working 4051, you can still see the characters you type faintly, and the cursor blink. Randy ________________________________ From: cctalk <cctalk-boun...@classiccmp.org> on behalf of Brad H via cctalk <cctalk@classiccmp.org> Sent: Tuesday, October 3, 2017 7:10 PM To: 'Pete Lancashire'; 'General Discussion: On-Topic and Off-Topic Posts' Subject: RE: Tek 4051 semi-repaired I’ll have to check that when I get it back – I didn’t really have a look inside and wouldn’t have known to look for that. I’m hoping not.. cosmetically the machine is excellent – the interior could almost fool you into thinking you were looking into a brand new Mac, with all that stainless. But that doesn’t mean anything in terms of the actual components, of course. My CRT guy seems to be convinced the computer isn’t doing what it should be, based on his read of the schematics. But he said the only way he could be really sure was to have a working unit to compare to. From: xyzzy...@gmail.com [mailto:xyzzy...@gmail.com] On Behalf Of Pete Lancashire Sent: Tuesday, October 3, 2017 10:01 AM To: Brad H <vintagecompu...@bettercomputing.net>; General Discussion: On-Topic and Off-Topic Posts <cctalk@classiccmp.org> Cc: Ian Finder <ian.fin...@gmail.com> Subject: Re: Tek 4051 semi-repaired If the CRT floods one can say the CRT is good with one major thing left, phosphor burns. In a DVST (Direct View Storage Tube) the most common effect is the burn area will not store with the same potential as the rest of the tube, or if burned enough will not store at all. There are other things that can go wrong but so far you know the flood guns are good, do you see the man CRT gun assemblies filament light up (can't remember if can been seen with the shield on) ? Good Luck, while at Tek I kept thinking of building one but never did. -pete On Tue, Oct 3, 2017 at 9:42 AM, Brad H via cctalk <cctalk@classiccmp.org <mailto:cctalk@classiccmp.org> > wrote: Also the computer itself *was* semi-working.. with the monitor board disconnected, voltages were good and I could blindly type in a simple endless loop program and get the ‘BUSY’ light to light up when I ran it. I don’t have the computer just yet and my tech guy didn’t have time to try entering something like that. So I’ll have to confirm. He seems to think three indicator lights on the right come up on power on now and then go out. The power light at the bottom appears to be dead. From: Ian Finder [mailto:ian.fin...@gmail.com <mailto:ian.fin...@gmail.com> ] Sent: Tuesday, October 3, 2017 9:39 AM To: Brad H <vintagecompu...@bettercomputing.net <mailto:vintagecompu...@bettercomputing.net> >; General Discussion: On-Topic and Off-Topic Posts <cctalk@classiccmp.org <mailto:cctalk@classiccmp.org> > Subject: Re: Tek 4051 semi-repaired Does it warm up or flood? "When I got my 4051, on power up there would be no voltage to the motherboard and nothing came up on the screen. That has been fixed, however we still do not have any kind of prompt or anything appearing." Care to share with the class what you've done so far? On Tue, Oct 3, 2017 at 9:29 AM, Brad H via cctalk <cctalk@classiccmp.org <mailto:cctalk@classiccmp.org> <mailto:cctalk@classiccmp.org <mailto:cctalk@classiccmp.org> > > wrote: Hi there, My go-to guy for CRT stuff has informed me that he has the CRT on my 4051 working and that the tube is good. When I got my 4051, on power up there would be no voltage to the motherboard and nothing came up on the screen. That has been fixed, however we still do not have any kind of prompt or anything appearing. Wondering if anyone has any ideas on where to go from here? I'm picking up the machine this week and will do some more testing.. hopefully the board didn't take any damage while he was working on the CRT. Brad -- Ian Finder (206) 395-MIPS ian.fin...@gmail.com <mailto:ian.fin...@gmail.com> <mailto:ian.fin...@gmail.com <mailto:ian.fin...@gmail.com> > <http://www.avg.com/email-signature?utm_medium=email <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> &utm_source=link&utm_campaign=sig-email&utm_content=emailclient> Virus-free. <http://www.avg.com/email-signature?utm_medium=email <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> &utm_source=link&utm_campaign=sig-email&utm_content=emailclient> www.avg.com<http://www.avg.com> <http://www.avg.com> <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> Virus-free. <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> www.avg.com<http://www.avg.com>
