75 280Z Clock Repair?

[zclocks]

Oh snap! This is the meter I purchased on Amazon several months ago and it works great. The box did said it was a multimeter?

https://www.amazon.com/Digital-Capacitance-Professional-Capacitor-Tester/dp/B07T9N2GLS/ref=sr_1_5?crid=68R71QQ2K9QX&keywords=capacitance+meter&qid=1695061403&sprefix=capacitance+meter%2Caps%2C172&sr=8-5

[HusseinHolland]

Been raining all weekend. Since I can't work outside, I got back on the clock repair.

First, I checked some of the remaining caps rated at 10uf. Most of them were 8-8.3uf (!) , others were 10.5 or higher. The .22uf caps were all under 2.1, most were .2 or below.

I removed the .22uf (read as .20) and one of the 10uf (read at 10.45) from the circuit board. The other 10uf read at 10.3, which was closer than most.

I found one .215uf and one 10.1uf cap, so I installed them.I also added 2 sockets (not in focus, sorry) to allow me to plug in various resistors if needed to adjust the resistance of the 2M resistor

Turns out, I didn't need that - with the replaced caps, the wheel was triggered & the clock runs. It's been keeping time since 2pm, so I'm hopeful that's that.

 

 

[zclocks]

Very good! I'm not supprised that the caps were out of tollerance. I've found so many lately that I check everything.

Make sure you start and stop the clock 10 or 15 times to make sure everything is good. 

Ron

[HusseinHolland]

24 minutes ago, zclocks said:

Very good! I'm not supprised that the caps were out of tollerance. I've found so many lately that I check everything.

Make sure you start and stop the clock 10 or 15 times to make sure everything is good. 

Ron

Will do! Thanks again for all the help!

[Patcon]

Another case of new parts not really being what you expect. Imagine how we could go around in circles because some part is "new" even though it's bad out of the box! Super of Ron to help point the right way!

[Dave WM]

hmm 20% off is not too bad with electro caps. Generally they have a pretty wide tolorance +/-. Seems like it should have been ok but maybe its a case of stacking with a non OE transistor. Anyway glad you got it going, but ditto the stop and restart check to make sure.

[HusseinHolland]

3 hours ago, Dave WM said:

hmm 20% off is not too bad with electro caps. Generally they have a pretty wide tolorance +/-. Seems like it should have been ok but maybe its a case of stacking with a non OE transistor. Anyway glad you got it going, but ditto the stop and restart check to make sure.

I see - I figured 20% was kind extreme, I assumed under 5% deviation would be more appropriate. Anyhow, I returned the set of caps, since all the ones I checked were more like 20% off listed value. If were to buy more, I would look for name brand, not even bother with generic.

Edited September 25, 2023 by HusseinHolland

[Dave WM]

%Oh yes, nichicon are the best, and get the 105c. I suppose modern caps are tighter tolerances as well so 20% was probably bad too. I was thinking of the old caps I used to run into on vintage electronics, they would often be like 100%+ 50%- rated, really wide ranges. This is stuff from the 1950's and 1960's. Tech has come a long way since then so I was off base on that 20%+-

[HusseinHolland]

So, I have the clock sitting on a shelf running. It loses about 5min over 48 hours. There is an speed adjustment marked S & F.

Question is, doesn't that mean rotate toward S to slow it down, and toward F to speed it up,

or vice-versa?

Edited October 2, 2023 by HusseinHolland

[zclocks]

S is for slow and F is for fast . Make very small adjustments as you can over shoot the time.

Ron