Yep - this is what I was talking about on my latest Patreon post! But even if I don't put any screws in, it's not happy ... weird, weird! www.patreon.com/posts/bbc-master-2-dec-117138815?Link&
shift-break to boot the disk auromatically on all BBC models with drives that contain a !boot file... ! "*." also gives the catalog, mode 7 was common for the ceefax/teletext service in UK. " *ROMS" list banked roms installed.. CONTROL BREAK Wipes the memory .. BREAK KEEPS MEMORY resident basic code.. oh my BBC Micros !! loved them little exspensive machines I could only afford a ZX spectrum back then lol but i coded them for a long time! .. actually the !boot file on a bbc the contents of the file is written in reverse per line??? strange!
Earlier I found that flexing the bottom left corner (where the audio circuity is) would kinda-make it work (posted on my Patreon with video) ... but I'm at a loss as to why putting it in the case with NO screws holding it down also doesn't work ... definitely something is marginal somewhere! Even outside the case it doesn't boot on first power-on as seen in this video ... I need to give it a hard reset with [CTRL] + [BREAK] to get everything in order ... I know the VIC has a 555 timer circuit that holds the CPU in reset briefly to allow everything else to come up first ... I wonder if there is similar here ...
That's a weird fault. I can't imagine it being your case, but you could put tape down on the screw supports and try it again. And I suspect that while pushing the board down in the audio section, you are raising it elsewhere. So pick up the upper right-hand corner and see if it starts to work.
Actually I did use tape - I put it on one of the stand-offs so it would stick to where it touched the underside of the board ... and that's where I found a pair of damaged pins! th-cam.com/video/F165aFLt084/w-d-xo.html
![🇬🇧 BBC Master Compact: Part 3 (Motherboard Fault) [TCE #0553]](http://i.ytimg.com/vi/F165aFLt084/mqdefault.jpg)
![🇬🇧 BBC Master Compact: Part 3 (Motherboard Fault) [TCE #0553]](/img/tr.png)
15:18 ooh, a mystery!
Yep - this is what I was talking about on my latest Patreon post! But even if I don't put any screws in, it's not happy ... weird, weird!
www.patreon.com/posts/bbc-master-2-dec-117138815?Link&
Yeah, maybe a mechanical issue, or capacitive coupling with the metal label on the back??
shift-break to boot the disk auromatically on all BBC models with drives that contain a !boot file... ! "*." also gives the catalog, mode 7 was common for the ceefax/teletext service in UK. " *ROMS" list banked roms installed.. CONTROL BREAK Wipes the memory .. BREAK KEEPS MEMORY resident basic code.. oh my BBC Micros !! loved them little exspensive machines I could only afford a ZX spectrum back then lol but i coded them for a long time! .. actually the !boot file on a bbc the contents of the file is written in reverse per line??? strange!
Works outside case but not inside - sounds like a marginal crack in a solder joint or trace, likely on the underside of the PCB.
Earlier I found that flexing the bottom left corner (where the audio circuity is) would kinda-make it work (posted on my Patreon with video) ... but I'm at a loss as to why putting it in the case with NO screws holding it down also doesn't work ... definitely something is marginal somewhere! Even outside the case it doesn't boot on first power-on as seen in this video ... I need to give it a hard reset with [CTRL] + [BREAK] to get everything in order ... I know the VIC has a 555 timer circuit that holds the CPU in reset briefly to allow everything else to come up first ... I wonder if there is similar here ...
Did You try to run it without the green work pad, just on the table? Maybe it's the pad what is making it works 😆
Yeah ... maybe I should cut the green pad to size so it fits in the bottom case, then try putting the motherboard in! :)
@@Brfff That's it! Or get a new motherboard. :)
That's a weird fault. I can't imagine it being your case, but you could put tape down on the screw supports and try it again. And I suspect that while pushing the board down in the audio section, you are raising it elsewhere. So pick up the upper right-hand corner and see if it starts to work.
Actually I did use tape - I put it on one of the stand-offs so it would stick to where it touched the underside of the board ... and that's where I found a pair of damaged pins!
th-cam.com/video/F165aFLt084/w-d-xo.html