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wayne.yl · 10-30-2007, 12:13 AM

I am wanting to replace the digital clock located in the top front storage cabinet. Ours is fried but not sure where to start looking for another.
Anyone have any suggestions?
thanks
Wayne

davidz71 · 10-30-2007, 06:31 AM

Factory optional digital or round type? I've seen one digital on ebay years ago and have seen several of the regular clocks on there as well.

Royce · 10-30-2007, 06:59 AM

This one would be cool. I think I will add one to the Minuet when I move the radio.

ThinkGeek :: LED Binary Clock

centennialman · 10-30-2007, 07:17 AM

When I replaced the old fashioned clock in my A/S I went to a clock store and they were able to replicate something that would work in my coach. At the time, they offered to do something in digital and I opted for the original look. The reason I post this is because you might want to go to some clock stores and see if they can help you out.

Steve

Lumatic · 10-30-2007, 07:21 AM

Anybody has any ideas for replacement insruments for my 71 Tradewind? Especially round instruments that are the same diameter as the originals. What was in my now empty holes in the control panel was an indoor outdoor thermometer and a barometer.

HiHoAgRV · 10-30-2007, 07:41 AM

The LED clock in my '77 was DOA

and I REALLY wanted it to work - Good luck on the search for a 12v replacement, I had no luck. I did find the reason mine quit and was able to repair it. The power supply on the board is a dropping resistor and a 9V zener diode. The zener had shorted and burned out the dropping resistor. I replaced both with a 7809 power supply chip and it's been glowing ever since. I think I did a thread titled "Mine Glows"

wayne.yl · 10-30-2007, 04:23 PM

Vernon,
I really think my clock died the same way.
If I can take a picture of the circuit board, do you think you could tell?
I know I have a burnt resister, from the look on the board. I was checking for ohms on the one in question and it is fried. I am really excited about this possibility of fixing the old thing. I am not an electrician by any stretch but my father was, boy could I use him now. But I did pick up a few things watching him over the years. I am pretty good with a soldering gun anyway. Maybe there is still hope for this clock.

PS Vernon, you mention a power supply chip but in on place you say its a 7809 and in another 7812.
Does this matter?
thanks

HiHoAgRV · 10-31-2007, 07:43 AM

I'll have to pull my clock and verify but I remember the Zenier being a 9V unit, thus the 7809 brain cells bumping together

. If you have a chance, post a photo of your P.C. Board and I'll try to pull mine and work up a method to check out yours. It might be a good thing for other members in the same situation.

I do recall the main clock chip is NLA but some surplus companies still have stock - at over $150 each

HiHoAgRV · 10-31-2007, 08:10 AM

Here is a quick sketch that may help you. The dropping resistor is easy to find, ts pretty much one of the first components after the 12v in and will probably should show 'open'. The zenier will be just after and will probably show '0' ohms in both directions. I removed them both and added the 7809 with some hot glue and jumpers (no filter caps at all!)

wayne.yl · 10-31-2007, 10:16 PM

Okay here is the board. My pencil points to the fried resister I think. Is The open diode just below the yellow 12v line coming in,(just to the right of the pencil lead on the first picture?
Again I appreciate the help.

HiHoAgRV · 11-01-2007, 08:18 AM

I just made a note in my 2do list to pull my clock and get some photos. If I don't get it tonight it may be next week.

From the looks, someone has already done some tweeking on your clock, hopefully we can get it going.

tschat · 11-01-2007, 09:05 AM

Wayne,

After looking at your photo, it appears that whoever did the prior repair had less experience at repairing electronics that yourself

. Since the diodes are simply a clamp device with the resistor being the current limiter, the 3 diodes in parallel (wrapped around each other) means they will quit working when just one diode fails.

There is good news in that all of the parts can be replaced to make your clock work again.

-thomas

HiHoAgRV · 11-01-2007, 11:07 AM

Quote:

Originally Posted by tschat

Wayne,

After looking at your photo, it appears that whoever did the prior repair had less experience at repairing electronics that yourself

. Since the diodes are simply a clamp device with the resistor being the current limiter, the 3 diodes in parallel (wrapped around each other) means they will quit working when just one diode fails.

There is good news in that all of the parts can be replaced to make your clock work again.

-thomas

Assuming they are zeniers

wayne.yl · 11-01-2007, 01:23 PM

thanks for looking into this.
I will wait for further instructions.
Now I know why the clock was removed from the cabinet and layinng inside of it. "Joe", the guy who sold me the trailer must have thought he could fix it at one time and apparently reached the limits of his expertise. Anyway, so have I, so you all are gonna have to carry the load to have a chance it will run again.
thanks
Wayne

HiHoAgRV · 11-02-2007, 08:02 AM

OK lets try this. The two photos should ID where to attach a 7812 (oops, you were right - brain fade). The red wire is hot, black ground and yellow is the regulated output. I didn't add any filter caps because there are already a good number on the P.C. board. Remove the diodes and the bad resistor and see how it ends up.

With any luck this should be my 500th and also a 'fix-it' post

wayne.yl · 11-02-2007, 05:21 PM

Okay I think I got it.
I will get the power supply chip tonight or tomorow morning.
I will let you know how it goes.

wayne
P.S. Congrats on the 500th and for sharing your knowledge of "fixin" things with me!

wayne.yl · 11-03-2007, 03:57 PM

You might not be able to tell but she works again.
I cannot say how happy I am that the clock works again.
It has one light out on the hour side but it is not noticeable on most digits.
I wired it just like you said using a three terminal 1amp 12volt regulator.
Thanks again for everything Vernon.
Wayne

HiHoAgRV · 11-04-2007, 06:15 PM

Cool -
Glad we could get it going.

Mikethefixit · 11-04-2007, 06:18 PM

HiHo Ag Rv and Wayne yl
Thanks, my 1977 Overlander's clock is also DOA. If the board is not broken or fried somewhere I think I can repair mine also. Ill take it out and report back
Thanks Guys
KA8 LMQ
Roger

HiHoAgRV · 11-04-2007, 06:29 PM

Quote:

Originally Posted by Mikethefixit

HiHo Ag Rv and Wayne yl
Thanks, my 1977 Overlander's clock is also DOA. If the board is not broken or fried somewhere I think I can repair mine also. Ill take it out and report back
Thanks Guys
KA8 LMQ
Roger

By looking at the design, I think they were taking a cheap way out using the design they did. Lucky for us 'cause it leaves a predictable failure mode for us to fix.

Good luck!