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View topic - Disabling timer of a SMS Display Unit / Kiosk

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Disabling timer of a SMS Display Unit / Kiosk
Post Posted: Tue Mar 10, 2009 3:40 am
Received this in the mail, thanks Ken!

Greetings,

I would like to inform everyone that it is indeed possible to disable the timer reset chip and in fact 1 unit out there already has an added switch on the back for disabling the chip.

Lets go back to 1987….

I was working at Montgomery Wards (In santa maria, Ca) and purchased one of  these units (For $1.00 complete with cartridges) that the company was going to throw away. I took it home and in fact figured out how to disable the reset timer. I hooked it to a switch I installed on the back or side don’t remember where exactly these days.

I loaned the unit to my brother so that his kids would have something to do while visiting him for the summer.

Unfortunately I never got the unit back as my brother sold it….Just one of many, many reasons I do not talk to him anymore. I would love to get my unit back if anyone comes across it or perhaps buy one that someone has up for sale.

The way I disabled the chip (which was very near the back end of the mainboard if I remember right) was I found the actual hardware reset (All master systems have one) and traced it back to the right chip (Possibly a 555 timer chip, but again it was along time ago) using multimeter to watch for the reset signal.

Once I had located the chip and pin that was sending the reset signal I cut the run and soldered a switch so that I could put it back into demo mode whenever I wanted to.

Thanks,
KJ

KJ Holm
Senior Designer
NAMCO NETWORKS AMERICA INC
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Post Posted: Tue Mar 10, 2009 9:03 am
I guess people are looking for a non-destructive way to disable it...
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viletim!
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Post Posted: Tue Mar 10, 2009 10:37 am
You don't have to be very destructive to paralyse a 555 timer. Connecting the trigger input to ground (with a crocodile clip if you like) should do the trick.
 
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Post Posted: Tue Mar 10, 2009 11:04 am
Isn't that the same as shorting whatever's triggering it?
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viletim!
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Post Posted: Tue Mar 10, 2009 11:32 am
Threshold, that's the one, not trigger. The one with the comparitor which measures the charging cap's voltage.
 
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Post Posted: Tue Mar 10, 2009 12:58 pm
Your slipping old man... :P
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Post Posted: Tue Mar 10, 2009 8:58 pm
If somebody could post up a picture of the kiosk board and outline exactly what I need to do that would be great (you wouldnt think I did a BTEC in Electronics and Electrical Engineering!).
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