Hour tile does not flip over. Hitachi KC770E

[Jakedang]

I have bought this Hitachi 770E digital clock radio knowing that the hour tile does not flip. I have shared some videos (on a YouTube unlisted playlist) showing that the minute flip display works as intended (flips every 60 seconds) and that the hour tile does not move at all despite manually advancing it. To me this suggests maybe the motors not the problem but rather the hour tile does not have enough pressure(?) to flip due to the hour gear slipping / not even moving? Please watch the videos and can anyone provide a solution as to what could be wrong?

cheers,
Jake

[gschmidt958]

Hi,
It would seem to me that one of the shafts related to the hour gear is slipping. It's possible that the gear is turning, but the shaft isn't. Maybe you could try putting a small dab of red nail polish on one side of the hour shaft to see if it moves.

Greg

[Jakedang]

I took the whole flip clock apart at the weekend several times. I WD-40'd several parts to get them to move properly as they were looking a bit dry, but it didn't seem to do much. I've got the clock totally apart now. I've tried moving the hour gear and the shaft connected to it seems to move as expected.. From closely looking at every part the only issue I can see is where the hour shaft meets the hour wheel. The end of the hour shaft looks like theres some sort of small internal chamfer? Same applies to the hour wheel. Although it looks like something may have slipped out at some point by the two tiny bumps there. I can't for the life of me imagine what could of happened in that small gap! Every other part of the flap clock mechanism looks fine really. Oh and I can't see any debris within the rest of the radio / clock in case something fell in there.

Hour shaft chamfer


Hour shaft chamfer close up




Hour wheel chamfer


Hour shaft and wheel next to each other (excluding spring for demonstration purposes)

[Jakedang]

This is the gap between the hour shaft and the hour wheel when partially reassembled. You can see the main shaft / rod that connects to the minute wheel, etc no problem. Does that look right to you?

I understand that the plastic part that extrudes out from the alarm wheel which has two prongs (one above and below the main shaft) engages and disengages by pressing up against the hour wheel.I know that has no means of driving the hour wheel as its purely dependant on the hour wheel being powered elsewhere. IE the hour shaft. So therefore I believe the alarm wheel is not what powers the hour wheel. I hope this makes sense.