1977 280z clock issue #xx of yy

[Captain Obvious]

9 hours ago, 240zadmire said:

if I flip the clock upside down, it spins just fine.  Just like if the clock was face down.  But up right, the pendulum wheel slowly stops.

What do you mean when you say the pendulum slowly stops?

Does the clock seem to work fine for a couple seconds in the normal position, but then over time the pendulum seems to lose amplitude and eventually comes to a stop? Pendulum won't start by itself, but seems to work OK for a little while if you give it a kick-start? I've seen that before.

Any chance you can post a video?

I'm with Dave... I suspect some long term drift of electrical components.

[Dave WM]

if it helps any, I just checked my working spare, it pulls about 10-12mA current on my Simpson 260. I will try it on a dvm later since I know most folks don't use analog meters, I don't know if it will be different but will check anyway. The idea being perhaps if there is a weak drive component then maybe you current would be lower that it should be. Would be nice to check the current before and after a recap/re transistor to see the diff if any. On my spare IIRC I only replaced the caps.

ok same on my DVM 10mA (still like my Simpson better)

 

Edited August 19, 2020 by Dave WM

[240zadmire]

2 hours ago, Dave WM said:

my guess is its just a lack of kick from the coil, in some positions just less of a load. My guess is a weak coupling cap or transistor.

I changed one cap already.  The one closest to the coil. The 0.22uf, can’t find in my spare parts.  As the other one is electrolytic capacitors?!?! Keep in mind about my knowledge of electronic components....
 

please see the video.  From face down, as soon as I plug the power in, the flywheel/pendulum swing right away.  As I turn the clock slowly up right it stops....

there is something about the pendulum, magnetic and the pink strike wheel.  I heard some other noise beside the ticking.

 

will need to put myself in zen mode to filter other noise and just focus on the clock

[Dave WM]

electrolytic caps are the most likely caps to fail as they are chemical in nature and can dry out. ESR meters are good to test them, I have used an audio tone as a quick and dirty test where you put the cap in series with a tone into a small speaker. Not a good idea if you have IC's but for a simple circuit like this it would be fine. You tuber (Shango 066) has been doing this for years as a quick way to test large value caps.

[240zadmire]

2 hours ago, Dave WM said:

if it helps any, I just checked my working spare, it pulls about 10-12mA current on my Simpson 260. I will try it on a dvm later since I know most folks don't use analog meters, I don't know if it will be different but will check anyway. The idea being perhaps if there is a weak drive component then maybe you current would be lower that it should be. Would be nice to check the current before and after a recap/re transistor to see the diff if any. On my spare IIRC I only replaced the caps.

ok same on my DVM 10mA (still like my Simpson better)

 

just borrow the DC rectifier from a friend.  Good to have friends with tools and willing to lend one!

Yeah, hard work directly on the car battery as you've seen on multiple photos. 

it is pulling 10mAmp on mine too.

 

I notice the pendulum wheel where it meets the pink gear to advance the second, need to be precisely align. Otherwise, it won't advance.  Also, there is a lot of play both the pink gear and the pendulum shaft.  I think it is design to be like that.  The pink can play up/down on it own axis and the pendulum also play up/down on its own exis.

 

[240zadmire]

I noticed the circuitry can be adjust to center the magnetic.  The nuts on both end of the pendulum can be adjust as well.  The black towel for the pendulum tension/winding, I will not touch it just yet as I believe it is for the winding strength of the pendulum.

another one is the “pressure” or “kick back” to prevent the pink tick gear from backing up.  Will not touch that.  
 

will have to get to understand the mechanical more ... might end up adjust the black tower for the pendulum winding 

Edited August 19, 2020 by 240zadmire

[zclocks]

The clock pendulum should work no mater what position you put the clock in. Your problem is the caps and the transistor. Replace them with exact values as marked. If you replace just one then everything might return to normal and then later the other cap(s) may fail. If the coils are good then everything should work. DO NOT start bending or tweaking anything. If you replace the components, 3 caps and transistor, the clock will work as usual. As I said before if you over heat the coil wires you can destroy the coils. 

There are other problems with the 76-78 mechanisms because plastic gears were used. However, replacing the 4 components mentioned should correct the problem.

[240zadmire]

@zclocks

Still observing...  

Where is radio shack when i need it!?!

 

i don’t think I’ll open up to clean the gears either, but then again, my evil curiosity might over take me.... so hard to control it.

will source then other components.  Will take some time shipping... 

[zclocks]

Well , RS is long gone or at least what use to be the Tandy Co. Look around in your area for an old electronics store. They are still around, but only a hand full still survive.

Where are you located? If you get parts on the web they only want to sell quantity, shipping is high, and takes weeks to receive.

 

[Dave WM]

I use mouser mostly when I was buying bulk for TV / Stereo repair. buy good caps nichicon 105c since its likely your clock will see heat.

[240zadmire]

Yeah, few cents a cap and $5 shipping.  Ridiculous if you don’t buy bulk.

Im in Southern California.  Orange County.

ill have to pay a visit to micro center and Frys.  They have a very small section of electronic component an probably $1 a piece... there used to be a few electronics around my area.  Doubt they still around.  Will keep looking.

 

funny thing, last weekend, diagnose home AC, (diagnose meaning google, YouTube) and try to find a local electronic store.  Zero come up.  Ended up ordered online and got it couple of days later.  Pop in and bam, the fan swirling back to live.  So relieve not spending a lot of money on motor, refrigerant ....

 

bricks and mortar is hard to compete with online nowadays

[240zadmire]

3 minutes ago, Dave WM said:

I use mouser mostly when I was buying bulk for TV / Stereo repair. buy good caps nichicon 105c since its likely your clock will see heat.

Yes, I like the website.  Easier to search than digikey.