New Life Games Tech Forums

Trying to get this MPU board up and running but only get a 71. .000 on the display.

it is plugged into known good I/O board, reel decoder and reel readers.

Have swapped all socketed chips with known good ones off of our test board with no change in the display (including both RAM chips, all PAL chips, EPROM's,  and MPU chip).

The test button works, hopper test, input and output test but reset doesn't reset board even though there is a good reset pulse reaching the MPU chip, I get a 71. .006 when I press the reset.

Close the "door" and hold in the coin in switch and no tilt is seen.

Anyone have any ideas on fixing this problem?

the 71 is door opened - not an error code.   if the test button is working for all tests - then what happens when you play a coin?    run a 2 test - that will activate all the IO.

Ya but, the same EPROMS - put into our good test board gives me a 50 code for door open with the same I/O board.

The I/O board is a known good board - the chips currently installed onto the bad board are all known good chips taken out of our good test board.

Yes a 71 code is door open for a board with EPROM's that initiate that feature but the EPROM's I am using on this customer's board do not support a 71 for door open
they will display a 50 for door open, like they do on our known good test board.

Coin in doesn't work and test 5 gives me all zeros no matter where the reels are placed.

The two input chips near the ribbon cable from the I/O board are also known good chips.

Maybe the other input chip - connected to the DIP switch is defective? It is still soldered to the MPU board and not in a socket.

I'll try that tomorrow unless someone has a solution.

test 5 and all zeroes - reel reader or io board issue

 
 

No, the reel decoder is a known good one and was tested with our good test boards to verify it worked before connecting the customer's board, so it is not the reel decoder board, but whatever is wrong with the MPU board causes it to not read the decoder board information (as well as give a 71 code) so the two are related to the same problem with the MPU board?

what m1 m2 m3 proms are you using?  those eproms are not compatible between E1 and E2 boards. 

EPROM's are not the issue. The customer's E2 EPROM's and our known good E2 EPROM's give me the same 71 results.

the 50 and 71 door open are nevada vs nj game.  not sure what causes the code.   if you are getting all zeroes on the readers - bad connection to the reel mech - bad control board - bad IO board. 
take the reel mech out - and then do the 5 test - if you are still getting all zeroes then it is the io board (or connections to it).  if you get a 1444 or 1xxx - then the reel mech is not being read correctly.

Consternation turns to elucidation!

It WAS the IC that reads the DIP switch.

It was holding the BD0 line at 1 volt.

That lousy chip had one job - read the damn DIP switch and it couldn't even do that without failing.