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TZ Clock is Broken or is it the PCB?

S

simonlindsay

Registered
Joined
Oct 16, 2020
Messages
15
Location
Derbyshire
Hello,

My TZ clock is not registering 2 o'clock, 3 o'clock, 4 o'clock 8 o'clock and 9 o'clock. I have taken the clock apart and cleaned the optos as best I can. The minute hand has always worked and still does but the hour hand seems to be at fault. I've tried using slow forward and checking the optos at the same time on the screen and at, for example 2 o'clock, one opto is still on when no optos should be showing.

My question is, could there be a fault with the wiring, pcb under the playfield or is the clock board faulty? Any help towards a better diagnosis would be very much appreciated. The CPU is brand new and a newer power board has been installed. I am looking to purchase a new Ingo board if the clock board is definitely faulty.

Many thanks in advance.

Simon
 
TZ clock is legendary for problems. The factory incandescent bulbs overheated it.

My game has a replacement board, NOS replacement gears and I installed extra washers on the gear spindles to remove play from the mechanism.

Many people buy a replacement board as the originals give nothing but trouble.

Your problem could be wiring, board, chips, warped hands, blown optos .......

Can you individually test the hour and minute hand optos in switch mode ? This might help you isolate the problem.

Opto boards run hot, this causes pins to tarnish. The chips are known to fail. Board tracks are known to fail.

One common solution is this....

https://www.german-pinball-modular.de/final-tz-clock-pcb-english.html
 
Hi DRD,

Many thanks for your very quick response. I have gone into test clock mode which shows the optos and the '9th column'. When the clock goes forward and passes 1:15, the hour does not change to 2 and as the hour hand goes back up to '12' the hour still shows '1' but the hands are at 2 o'clock. At this point the optos should be off on the switch matrix to denote 2 o'clock but there is still none showing. As the clock then progresses, the hour jumps to 6 o'clock after passing 3 o'clock then goes back to 5 as it eventually reaches 5 o'clock. It's all very confusing. The optos seem to sync with the switch table. Maybe I could upload a video to explain a bit better?

Thanks.

Simon
 
It is indeed a most unusual clock. (Which gave me no end of problems when I had a TZ :)
Think I drilled holes in the top of the case to help it cool.

I vaguely recall reading that the clocks illumination wasnt meant to be on the GI circuit. but they ran out of room on the lamp matrix so they had to make it GI.
 
When you run clock test there are 8 boxes. When the box is empty it means the opto is not triggered so it is open. When the box has a + sign in it it is triggered or closed. If you do a 12 hour cycle you can verify whether all optos are working as they should all either be "open" or "closed" at some stage of the 12h cycle.

Hopefully, just one opto is malfunctioning. This is enough to cause chaos with the clock. When you know which one it is you can investigate further. It might just be dirty. Optos are quite simple to replace if you are comfortable with a soldering iron.

Others will know better, but a sensible order ...

So is the opto dirty ?
Do the plastic shrouds on the hands physically interrupt that opto properly ?
Is pin/ socket tarnished ?
Check board under magnifier for broken tracks from that opto (use continuity on multi meter)
Replace opto
Replace comparator chip

Buy a new board
 
Hi,

Thanks for the replies. I have now uploaded a video to youtube -

I think the issue is with the 1 hour opto as the switch in column 9 (4th from the bottom) does not trigger or remains on. Hence why the 2nd hour does not show, or am I wrong?

The next thing is how to fix it? Where can I get a replacement opto if it cannot be cleaned?

Thanks again,

Simon
 
Update. It is definitely the 1 hour opto that is not working having checked the 12 hours completely through. Will attempt to clean again and use isopropyl alcohol instead of window/glass cleaner. If that doesn't work I'll check the wires and look for cold solder joints and check the traces but I don't know how to check the comparator chip that DRD mentions. I'll also give the pins a quick sanding in case they are tarnished.
I have found a replacement opto at Pinball Heaven (pinball.co.uk).

If all else fails, I'll get a new Ingo clock board from Germany (just awaiting a response from Ingo Kramer about availability).
 
I would just try and get the Ingo board if you can, got mine a year ago. There was an after market clock board fitted that was broken, nothing compares to Ingo’s board.
Heard that people were waiting quite a while though to here from him, mine took a while to arrive. Very happy with his board. One less problem.
 
UPDATE:

Yesterday I took the clock apart and tried cleaning the hour opto with isopropyl alcohol and a q tip. The bottle was new with a spray button which blasted stuff all over the board after a couple of squirts. So, I cleaned the residue away and put the clock back together. Went into test mode and the clock registered 0 o'clock with none of the hour optos registering, only the minutes.

Next I took the clock apart again and separated the front and back boards and gave it all a good wipe down with a microfibre cloth including the other three hour optos. I put it all back together and HEY PRESTO!!!, the clock works fully. I couldn't believe it, so I checked it again today and it is still still working exactly as it should - amazing! I've saved well over £100.
 
Delighted it is fixed. May have been dirty connectors or dirty optos - but at least you have narrowed this right down

This clock may well become part of your lifestyle. Needing maintenance twice a day like teeth or twice a year like the dentist. But make no mistake, that bloody clock is a new member of the family
 
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