SG-112B stopped working, help please

[ricand]

This machine has been working great for years and it just stopped.   It powers up, goes through the self test and this screen comes up, normal top part but no cards.    Bills go in without any credits, coins drop right through.   Buttons are all off.   I printed out the manual i found for the S112 Plus.   I can't get into the main menu.   I've tried the reset key, red test button on front then reset and red button on front plus reset.   It doesn't seem to do anything.   Anyone have any ideas on troubleshooting?   I'm decent with electronics and have a good meter.  Thanks in advance for any assistance.

[KirkLasVegas]

Inspect all chips that plug into the board. CAREFULLY remove one at a time,clean pins with a blade and reinsert them
Pins should be bright and shiny..if looking dull they dont make good contact.


Kirk

[ricand]

Inspect all chips that plug into the board. CAREFULLY remove one at a time,clean pins with a blade and reinsert them
Pins should be bright and shiny..if looking dull they dont make good contact.
Kirk

Thanks Kirk for your response.   I will give that a try and report back. 

[KirkLasVegas]

Yes..please do!
Especially look at the RAM chips.....as this is where failures have happened before....

Kirk

[ricand]

Well sadly removing the chips and cleaning off the oxide on the pins didn't help.  I did all of them that were in sockets.    It looks as if they've been removed and reinstalled poorly sometime before I got the machine around 2001, but the integrity is still there. 

It goes through the 'self test' fine.  It's also displaying the fixed graphics ok, so something is feeding the monitor a decent signal.   It's hanging somehow right before it 'deals' the cards.  It seems to ignore the signal to add credits as well, since the bill changer accepts dollars but doesn't register them.    It does register the door opening with the alarm signal and the V-M-Door on the display.  The correct way to try to get into the main menu is to press the red button under the monitor (the middle that says TEST, not the one on the monitor chassis) and then the reset key on the top right side outside the unit, right?   It seems that should work as well, but doesn't.    Should I try to find a rom set and replace it?   I just don't know where to go from here.   The only other thing I would know to do would be to check the supply voltages.  Im thinking it would have a problem with the self test if the supply voltages were off though.   Thanks again for any help.

Edit:   I noticed there is a battery on the board.   I've never replaced it, could that be a problem?

[Amachanic]

Edit:   I noticed there is a battery on the board.   I've never replaced it, could that be a problem?

It's very possible that is you problem. Have you check it for voltage? For a couple of dollars I'd give it a try.

Gary

[LeisureTimeSlots]

Ck battery voltage  3.6 and perform a ram clear.

[ricand]

Ck battery voltage  3.6 and perform a ram clear.

How do I perform a ram clear on this machine?   I can't get into the service menu.   Is there a physical chip like slots have?  Sorry I'm such a noob.