Unfortunately it does show what sort of a muppet I really am though.
My Arduino has a USB type B connector and it was shorting out on the underside of the 100nF capacitor.
It wasn't until TY said "you can remove the plastic pin separators to inspect under them" that I thought to my self when I did that. I had better check nothing is shorting as the clock board would be closer to the Arduino if I fully seated the two together. It was at that point I spotted my problem
Well I just want to say a special thank you to TY. You have been so patient through out this whole issue and I really would of give in to buying another clock board if you hadn't been so helpful.
So Many thanks again TY and Ian for your help and I'm looking forward to finishing my clock
All the best
Excellent!! I don't think I would have ever thought of that without seeing it live and in person. What an obscure problem... but now that I put a picture of an Uno next to the board picture from the manual I can see it. Metal shielded USB connector directly under the pads for C7, add a little pressure and BOOM. Time to put a sticker or some black tape on that USB connector!
I'm glad to see this resolved - it was bugging me thinking I was overlooking some obvious explanation. I find it a bit disconcerting that the regulator on the Arduino cooked. I guess the AP1117s aren't short circuit proof like the old school 7805s were. Progress?
Anyway... happy to help out. I enjoy the challenge of trying to troubleshoot by "remote control". Fun and frustrating at the same time. I dunno if I'm actually patient or just plain stubborn.
Look into it later when the dust is clearing off the crater.
Hmmmm, I moved that capacitor for that reason after the first revision of the board. I wonder if you got a first revision board by mistake. This was the only adjustment that was made between the first revision and the second. I have a big box of PCBs and I wonder if I grabbed the wrong one. If so, I'm really sorry that it caused such a problem. The correct revision looks like this, where you can see that C7 does not collide with the USB outline (in white):
Hi Ian no worries I should have got an Arduino with a USB C connector. That picture looks really close to what I have but C7 looks like it is further down by about 2mm than that one and slightly further to the left by 2mm or so like this. It only just touches the usb shielding and my solder is really small and flat there but it still touches.
Hope this helps.
Last edit: 3 years 3 weeks ago by Ty_Eeberfest. Reason: Inlined the attached pix
You know what, that looks right to me. I wonder if it is an out of spec (or perhaps mine are out of spec) Arduino board. I am not 100% convinced that the USB connector position or format is "regulated" by the design, and I suppose it might be able to vary and still be "compatible" (not that Chinese low cost suppliers would care that much about it anyway even if it was "regulated").
Hm, no, I take it back. It looks like you got a rev1 board. I'll willingly replace it if you want. It must have been late and I must have fished the wrong board out of the box. My bad for keeping them in the same place.