Digital Clock

[Rich H]

The two crystals are totally different sizes.

It's been a good few years since I took a clock apart. I'd need to see a photo of the one on the clock to tell you which....

[Rissy]

...ok, so i've got my clock in complete bits now. Been busy identifying parts and testing where possible.

I'm tending to agree through the process of elimination that Rich H is correct saying it's the crystal.

I'll give a full run down, and post piccies up when i have time, but in the meantime, i need help identifying this component.

I think its a 10pF capacitor. If it is, I can't get it to accumulate a voltage from the multi-meter the same as i could do with another 22uF capacitor from the board, so i'm also suspecting this to be at fault. As i say, i'm not sure what it is, only suspecting, and am also having trouble sourcing internet pics or even a suitable replacement.

Can anyone help?

Piccies:

[Rich H]

Yes it's a 10pF capacitor

You won't get it to show a value on a multimeter since it's capacitance is minute, it'll take
a fraction of a millisecond to fully charge, so it'll show as open circuit.

It's very, very unlikely to be that. If your clock isn't running, but it lights up then logically
the IC isn't getting the pulse to make it run. That comes from the crystal oscillator circuit,
of which that 10pF is part. A 32.768KHz crystal is used in virtually every quartz based clock
circuit since the beginning of time. Since the crystal is made from just that, a tiny sliver of quartz
crystal, they are very fragile, hard to make connection to, and whilst not prone to failure -
and assuming you've checked the circuit board properly - is the most likely
(and cheapest) thing to replace first of all.

[Rissy]

Ok, so here's the evidence of my hard work over the last couple of days.

First the clock as removed from the housing, taken out of the car.





Second, the dis-assembly starts...carefully!







I did a full clean up of the circuit tracking at this point and removed as much of the old solder as possible, from EVERY joint, and have already started re-soldering in stages with new solder. This will obviously continue until the whole thing is in one piece again.

...Next was to test all the components, taking some off the board for proper analysis.



Finally, identification. You can pretty much find it all on the internet with these details on the picture, except i'm not sure about the trimmer capacitor, and of course, the irreplaceable Vacuum sealed digital display unit at the top...



I'm going to replace the crystal in mine (since it seemed to just be the pulsing for keeping the time which has stopped - so no clock frequency means dodgy crystal - a few of us think). I'll most probably replace it with the 12pF version (as noted in the picture, as i think its the most likely candidate) and then I'll put it all back together and retest it. (Hopefully i'll NOT have to take it all apart again! - It aint easy getting off that Vacuum display!)

Maybe this will come in useful for someone else in the future...? It's here for prosperity now anyway.

[Nick H]

Good stuff.

As I had 5 minutes, I did a search on VFD displays. Appears the Russians are still into these. Check out this site. Not sure if this display would fit? £44 not bad on price and able to run on 12V.
http://www.kosbo.com/index.php?page=shop...&Itemid=18

If you get really stuck, these guys appear open to product suggestions. I reckon they could knock us up a new custom clock.

Nick

[stunned_monkey]

When i originally got Lex, the clock display worked intermittently. By opening it and poking around I found the transistor that lives on the very edge of the board and has a very teeny tiny crappy solder join which I fixed. Thereafter the clock worked fine but you needed to connect the battery at 12:00 because the pin switches didn't work. I never bothered taking it any further because you can't read the clock when sitting in the car anyway...

[Rissy]

...this is really interesting. I had no idea stuff like this was still being made. Trust in the Russians, eh. I know from personal experience working over there, that they do enjoy keeping existing known working solutions for stuff working. I guess it's a case of, if they have the equipment and the know-how already, then this is potentially cheaper than investing in all new designed solutions and gearing up to make them, which in many cases these modern new solutions are a close fit, but not the exact same in functionality.

Just for info, I've also opened communications with a chap called Phillip Knotts from Dakota Digital: http://www.dakotadigital.com under their custom dept.

He already has a tried, proven, tested and even bought solution for replacing our clocks. (From the website you put a link to earlier in this thread - I had already seen it, and got in touch with this guy before hand)

He has the design, and has sold this to a few customers already. His solution only has 3 out of the 4 connections, which means I'm pretty sure it doesn't dim with the headlights switched on like the old one does. The display is a close fit, pretty damn close in fact, but not exact. I'm not sure about the ":" in between the HRS and MINS being there, or even flashing either...?

Anyway, he's charging $145 + Shipping charges to build one at a time. BUT, he was requesting that I send him the housing for the clock from my car, which is where his circuit board would occupy. As you can imagine, I wasn't best pleased with sending him irreplaceable parts off my car when in fact all it requires is for him to make it, and send it out, and let me finish off the job (if I cannot fix my old one of course). So I enquired (or should I say inquired) to the potential of him doing this instead, even if it requires a small printed instruction of the final soldering of the wires etc on to the board.

....I'm still waiting his reply.

On a side not on repairing my old one...still going on. I think I'm going to replace the two transistors on the board too (since they are available through ebay - in a rare fashion). Although they test ok, I'm slightly worried in the fact that when my clock froze before, the HRS and MINS adjust buttons also no longer worked, or the dimming functionality with the headlights being turned on. I'm not completely sure of the functionality of all the individual components on the board yet, not without closer analysis of the circuit tracking on the under side to try to deduce, so I'm still somewhat "clutching at straws". Anyway, I'll keep you posted on the end developments after rebuilding the clock, and retesting with the replaced crystal and transistors.

[Rissy]

....Check out what I've found!

This is pretty close. I think it may be a successor to our model. No longer made, but LOADS available! over 31,000 of them from this source.

Ours is the Futaba 4-BT-02s (36-pin)

This one doesn't have the same pin configuration (I think this one is only 16?), but i'm wondering if with the datasheet, it could be figured out how to get this to work on our circuit boards with our clock chip!?

http://www.wellgainelectronics.com/futaba4-bt-05.aspx

http://www.ebay.co.uk/itm/FUTABA-4-BT-0 ... 259wt_1064

I'll keep scouring around, see if anyone still has our 4-BT-02s available....

[Rissy]

Rissy Wrote:Ours is the Futaba 4-BT-02s (36-pin)

Sorry, 34-pin.

18 on one side, and 16 on the other. (See photo above)

[Rissy]

Here's a promising source, although i'm confused about their remarks under "Package" (Top entry on the list at this link):

http://www.electronic-search.de/cgi-bin ... rtikel.txt

[Nick H]

31,699 VFD display in stock! :lol: Even if it is the newer version.
Amazing what you can find when you know what it's called!

As long as the dimensions are the same. I guess you could get the board made
to suit from that site I found. As they have all the existing tech to drive a VFD
display. Looks like their into "retro" stuff bet they love to say they did a DeLorean Clock :wink: . Check out the custom one they did for a Mini Cooper on the site.

Nick

[Nick H]

Hi all,
I contacted Konstantin @ Kosbo.Com. Regards remanufacturing the clock. As for some reason I am finding this quiet interesting :lol: .


Here's his reply:-

Hi Nick,

Are you back from the future? ;-)

It's very interesting and I did not know that this car has VFD display in
it.
Yes we can make new clock, no problem.
How many clocks do you think your club would need, just one?
Or this clock is headache for lots of cars and it's better to replace it...
I ask about it, as it's not cheap to design/make new clock just for 1-2
replacements
If we can get about 10-20 orders, then I would not charge you for design and
clock would cost about 40-50GBP
You will get 1 year warranty and a few more features we can implement into
the new clock too.

Could you also give me dimensions of display and clock board, so I can start
to think/work on initial design...


Let me know what do you think about it


Best regards, Konstantin
http://www.kosbo.com

Rissy do you think you could give Konstantin the dimensions as you have the clock out?
This sounds quiet good to me. I'd order one for £40-50 quid to have as a spare as they are not available.
Plus this would be a proper VFD display not a modern replacement.

How about a show of hands of those who want a new clock?

Regards
Nick

[Guinney1971]

all interesting stuff, my clock is more random then a DMCH fuel sender lol

Mine briefly flashes up the (wrong) time, then goes off again.

I guess its on the 'to do' list......

[Rissy]

Nick H Wrote:Hi all,
I contacted Konstantin @ Kosbo.Com. Regards remanufacturing the clock. As for some reason I am finding this quiet interesting :lol: .


Here's his reply:-

Hi Nick,

Are you back from the future? ;-)

It's very interesting and I did not know that this car has VFD display in
it.
Yes we can make new clock, no problem.
How many clocks do you think your club would need, just one?
Or this clock is headache for lots of cars and it's better to replace it...
I ask about it, as it's not cheap to design/make new clock just for 1-2
replacements
If we can get about 10-20 orders, then I would not charge you for design and
clock would cost about 40-50GBP
You will get 1 year warranty and a few more features we can implement into
the new clock too.

Could you also give me dimensions of display and clock board, so I can start
to think/work on initial design...


Let me know what do you think about it


Best regards, Konstantin
http://www.kosbo.com

Rissy do you think you could give Konstantin the dimensions as you have the clock out?
This sounds quiet good to me. I'd order one for £40-50 quid to have as a spare as they are not available.
Plus this would be a proper VFD display not a modern replacement.

How about a show of hands of those who want a new clock?

Regards
Nick

Nick,

This is a very positive response indeed. The chap definitely sounds quite keen.

Just another another side note, the chap at http://www.wellgainelectronics.com/futaba4-bt-05.aspx has confirmed that they only have the 4-BT-05 and 4-BT-07's. No 4-BT-02 in stock there)

For the other link posted above: http://www.electronic-search.de/cgi-bin ... rtikel.txt

I have gotten in contact with these people also, just to confirm that it is indeed our display they have (unknown) quantities of. I've attached a photograph of both sides of my own on my email, to confirm that it is indeed the exact same part. I've asked for confirmation of the part, and also an estimate of cost per unit or in multiple quantities, if indeed the same unit type.

As for your investigations (I know what you mean about finding this quite an interesting topic lol!)

I've taken some measurements, but I think it is a little more complicated than this if we are to get as close an alternative as possible to fit our existing enclosures, and with the same functionality as we have now (constant supply after ignition turned off, as well as ignition sensing and headlight sensing for the auto illumination and dimming respectively, with the existing 4-wire connection we have in our cars.
Not to say this is impossible, but i think the chap might have to backwards engineer our circuit, and understand what each of the connections is (maybe someone here more familiar with the car wiring fixtures could help us identify what each of the 4 wires are. I'm presuming 12V supply, 0V line, and then two inputs, one for ignition input and the other for headlight input....? But I don't know which way round right now....?
Also, for the purist, I'm sure we would want the new clock, if we pursue this, to both fit into the existing enclosure AND work in harmony with the green lens, meaning the HRS and MINS increment buttons would have to be positioned under where the holes are for sticking in your wooden tooth pic or whatever other implement people have adopted for adjusting the time on the clock (when they work!)

I think, since you have opened communications Nick, it is best for you to continue. Of course, I will help out wherever possible. I'd definitely buy one for the price quoted!

Anyway, here's some dimensions, and photos which might be of some additional help to you with talking to this guy. I will of course update on the answer I get back from my latest endeavor too.

Circuit Board:

Through-hole, single side tracking

Width: 54mm
Height: 39mm

HRS and MINS increment button centres should be placed at 3mm from bottom edge of circuit board, and starting from the bottom left corner, the HRS increment button centre is placed 11.5mm to the right and again from the bottom left corner, the MINS increment button centre is placed at 39mm to the right.

The height of the completed assembly should be no more than 16mm from the stubs of the soldered components on the underside of the circuit board to the front face of the VFD display in order to fit in the existing enclosure. This will ensure it fits under the green fascia cap which we are all familiar with being the thing we see as the clock from the cockpit of the car.

The actual inside measurement of the enclosure the circuit fits into is 62mm by 46mm.

I hope this helps. Below, some more pics. If there are any others you need before I put all my stuff back together again late this week hopefully, then let me know.

[Rissy]

...Keeping options open, I've had more word back from Dakota Digital regarding their modern update equivalent.

The guy I'm talking to, has to still talk to the guy who makes them.

I've mentioned to him that there are potential alternatives in the pipeline, and have as a result, aired the subject of potential price haggling. (I AM a Scotsman after all :wink: )

I've also suggested to him that there could indeed be a proper market out there for his clock. As we all know, there are literally hundreds if not thousands of potentially malfunctioning clocks out there just begging for a replacement if they cannot be repaired.

Anyway, I'll keep you all posted.

Looks right now though, that with the communications Nick and I have started with companies, there may be more than one viable option open to us owners. 8)

Now all we need, is more interest from people in order not to lose theirs.