[DC]

Hi again Windell (it’s that time of week!),

I double checked all the connections, checking that there were no shorts between any of the LEDs or between any other lines where there shouldn’t be connections using the circuit diagram. I couldn’t find anything wrong so in a trial and error approach I replaced one of the problematic blue LEDs and that solved the problem with those red LEDs, so I went onto replace the other two as well. I notice that when a couple of other blue LEDs light up, two red LEDs also light up simultaneously, but just very, very faintly… you can’t see this when it’s functing in time-mode only in alignment-mode. So I’ve reassembled the whole clock as I think it’s working as best I can get it without an entire overhaul of all blue LEDs which I’m really reluctant to do. I just hope that the slight lighting up of some other red LEDs in conjunction with the blue LEDs isn’t a sign of a future fault creeping in. I’ll keep an eye on it anyway.

Thanks for all of your correspondance over the last few weeks. I really appreciate the help as well as your speedy and friendly responses.

All the best,
Donna

[DC]

Yes, I get approx. 24.5 Ohms between each of the relevant chip output pins and the LED jumper connections on the red ring apart from LED10 which I (correctly) measure 68 Ohms. So that all looks good…

[DC]

Hi Windell,

I got another European adapter, just like the one you described but the problem remains.

I checked and I can’t measure any resistance between LED10 and any of the other LEDX connections. I double-checked continuity between LED10 and the other LEDX connections and also got nothing, so no short circuit.

I also checked for shorts betweeen pin 15 on the ATMega chip and the other pins and also no problems.

I used my arduino to light up D45 and when I do this D410 and D105 also light up (although only slightly, probably as I’m only using the 3.3V output).

When D45 is ON, 4 is HIGH and 5 is LOW. So I don’t understand how D410 and D105 can both be on simultaneously. For D410 to be on, 4 is HIGH and 10 is LOW. But for D105 to be on, 10 needs to be HIGH and 5 is LOW. So how can 10 be both high and low simulataneously to create this situation? The same goes of course for the other leds which come on along side D16 and D42.

I’d be very grateful for your input again.
Cheers,
Donna

[DC]

Thanks, will do this on Thursday and let you know how I get on. Will leave you in peace for a couple of days :-)

Cheers!

[DC]

The power supply cable supplied with the clock (purchased from Jameco Electronics in the US) is model FY0501000 with US connector:

input 100-240VAC 50/60Hz
Output 5VDC 1A

I’m in Europe on a 230V and 50Hz mains voltage, using a travel adapter.

[DC]

You’re right, this doesn’t make sense. I just double checked the LED numbers and you were correct, I had read these the wrong way around… here’s what we actually have:

When Blue D45 is ON, Red D410 and D105 are ON
When Blue D16 is ON, Red 111 and 106 are ON
When Blue 42 is ON, Red D102 and Red D410 are ON

Do you know from this what’s going wrong?

Thanks so very much for your patience with this (and me!)

[DC]

The red dial LEDs all work great, not a twinkle from any of the other (blue) LEDs when each of them is on…

[DC]

Hi again Windell,

I’m working overtime on my clock at the moment. The blue and green ring were working great so I reattached the red ring. Upon alignment the red ring is working great too.

However, now that the red ring is attached, when three of the blue LEDs light up, two of the red leds are simultaneously on:

When Blue D45 is ON, Red D510 and D104 are ON
When Blue D16 is ON, Red 101 and 610 are ON
When Blue 42 is ON, Red D210 and Red D104 are ON

:-(

Any idea what’s going on? I thought I’d finished the fault finding but now this! The Blue ring worked great before attaching the red layer.

Cheers again for sharing your insights.
Donna

[DC]

Hi again Windell,

My green ring is working again correctly but upon testing I notice a slight flickering on LEDs D92 and D48. Any ideas what might be causing this? All other LEDs are fine.

Many thanks again for your assistance,
Donna

[DC]

Hi Windell,

Great news, I’ve finally had the chance to sit down with my clock again and I identified the fault… between R9 and pin 5 I could not read any resistance so was worried about an open circuit although I’m not sure I really understand this measurement because the resistor is already wired into the circuit so wouldn’t I just be measuring the rest of the circuit anyway?

So, on further investigation and in looking at the circuit diagram, I saw one end of R9 connects directly to the LED9 jumper… however, if I measured for continuity I found none between that end of R9 and the jumper… An open circuit between R9 and jumper LED9 (on the PCB itself!). The PCB looks good visually, so this is strange.

But anyway, I wired R9 and LED9 up directly using a banana connector and when I do this, the clock works fine. In this case, I guess I’ll just solder a small jumper wire into the back of the blue PCB to connect these two points up.

Again, unfortunately, I have to leave my reassembly until next Thursday but I’ll confirm if this has solved all the issues next week.

Thanks for your assistance, much appreciated!!!
Donna

[DC]

Hi Windell,

Thanks so much for the speedy response and the advice. I have just one afternoon a week to work on my electronics projects, hence the delay in my reply… so I’ll investigate further tomorrow and let you know how I progress.

I really appreciate the information and the support.
All the best from Europe,
Donna

[DC]

Thanks, fixed. Polarity of D61 was incorrect. Silly error. Many thanks for your time responding

[Author]

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