Is it safe to reconnect a presumably broken PROM connector pin?

Question

I am trying to understand (and fix) a soda machine that doesn't seem to accept 1€ and 2€ coins while all stickers (inside and outside) seem to imply that they should work (5ct to 50ct do work).

I noticed that the coin validator (class "MS 1000" by Mars Electronics International) has a broken pin (see the picture below). According to the PROM's datasheet, that's the A7 pin, but that doesn't tell me anything (I haven't found any documentation on the MS 1000).
I have not yet removed the board from the case because it sits very tight and I don't want to break it, so I don't know whether the pin is connected on the board.

Is that necessarily a problem or is it possible that this is intentional?
Is it advisable to reconnect it?

It pretty much looks intentional, you might want to consult the datasheet what that pin is about, and look where the trace goes that would connect to it — PlasmaHH, Nov 08 '17 at 12:34
That's the A7 pin. I'm pretty sure the other half of the PROM contains a different set of data, e.g. a factory test routine. — Janka, Nov 08 '17 at 12:44
TTL inputs default to high, so it may still not be a problem regardless. — Ignacio Vazquez-Abrams, Nov 08 '17 at 12:56
Is the trace that would be connected to that pin connected to anything else? — ratchet freak, Nov 08 '17 at 13:08
maybe you can enable some sort of secret special debug mode that includes a full version of doom for testing... but probably not — BeB00, Nov 08 '17 at 13:52

score 1 · Accepted Answer · answered Nov 12 '17 at 08:48

1

This is only a partial answer - I don't know if it is safe, but I do know that it is not a problem.
The issue with the coins was that there was too little change available and the warning lamp was broken. The soda machine works perfectly with the pin disconnected.

answered Nov 12 '17 at 08:48

Imanuel

161
4

If this solved the problem then please accept your own answer to make it clear that it is solved. – Transistor Nov 12 '17 at 09:46

Is it safe to reconnect a presumably broken PROM connector pin?

1 Answers1