Working(?) VFD but NO DISP Shown on LED Display

[jtwine]

So I have been searching through both the main site and the archives and have not do not think I have stumbled upon this exact problem.  For no apparent reason, my S2000 has started showing NO DISP on the LED display and is otherwise unresponsive. 

History: my first S2000, purchased recently.  Battery corrosion arrested (hopefully), Varta battery removed, coin cell replaced with a CR2032 holder and replaceable battery.  Bought a BettorSlots TITO unit and installed it successfully, but the system seems to reject tickets.  Removed BV and cleaned heads and sensors, replaced.  Then the trouble started.

Symptoms: The VFD display appears to start up correctly and passes its self test, but then sits there for a little bit and never goes to the memory test content.  Instead, it eventually goes blank after about 20-30 seconds (it does NOT display a NETPLEX error), the BV cycles, the reels spin to the last game's positions, and then nothing except NO DISP on the LEDs, cycling between that and the number of credits last played.  BV can be heard "twitching" every few seconds.  No button deck lights.  Seems unresponsive to both the test button and the attendant key (I tried navigating the menus blind to get to auto-configuring the NETPLEX devices, but nothing seemed to happen because the BV did not cycle again.


What I have tried (which made no difference):

• Reseating the BV
• Removing the BV entirely
• Reseating the Bill Box (figured, why not?)
• Removing the Bill Box entirely
• Reseating the Power Supply
• Reseating the Printer
• Removing the Printer entirely
• Reseating the cables related to the VFD
• Reseating the MPU board (while it is disconnected the VFD will show a NETPLEX error after the self test)
• Tightened screws at the BV's connector because they were loose
• Opening and closing the main door (and latching it) multiple times before and after each item above

Also note that there is no hopper in this machine.

I am going to try disconnecting the BV's connector from the harness when I get back to the machine later today, JIC something is wonky with the connector itself.

I am reluctant to try a clear key because with no display it will be difficult for me to navigate the menus.  I am also reluctant to pull the battery because if it is really not responding to the attendant key, I could be stuck at the RAM ERROR tilt and now have two problems.  I am currently looking for a replacement MPU just in case, but would appreciate any other ideas if anyone has any.

Nothing appears smoked on the MPU board, but I am going to print out some schematics and start working through the NETPLEX-related components if no other ideas come up.

Anyone got something I might have missed?

Thanks!

Peace!

-=- James.

[RB]

Any fault in the netplex circuit can cause the no disp on the 7 segment LCD. A faulty BV, or printer or installing one with the wrong firmware or protocol commonly causes it. How about the VFD itself and/or the controller? Try swapping those if you have any.

[jtwine]

Any fault in the netplex circuit can cause the no disp on the 7 segment LCD. A faulty BV, or printer or installing one with the wrong firmware or protocol commonly causes it. How about the VFD itself and/or the controller? Try swapping those if you have any.

I might not have been clear enough in my post, but everything was working correctly (read: the game ran and played, the BV accepted bills, credited appropriately, and I could cash out via ticket) prior to my cleaning the BV because it was not accepting tickets.  No components were swapped and no firmware changes were made.  I do not have any spares to swap with (yet), but I am working on that.


If any fault could could cause the NO DISP issue, what are some examples that would not have been caught in the steps I already tried?


Thanks!


Peace!


-=- James.

[Retro tech repair]

Depending on your sg chips No disp will not shut down the game. As stated start checking all netplex devices. Un plug printer disconnect the bill acceptor. You can try replacing the vfd or its driver if you have a 2 piece vfd. Also check the wires running to it and accost the door hinge. Just because it sees the signal from the mpu and can display data doesn’t mean its transmitting back to the mpu. If the display is saying netplex link down then the display is faulty or the harness is damaged. Netplex link down is not a machine error its a display error. That error is will show even if the display is powered up not connected to the machine.

[jtwine]

... As stated start checking all netplex devices. Un plug printer disconnect the bill acceptor.  ...  Also check the wires running to it and accost the door hinge.

From the original post:

What I have tried (which made no difference):

• Reseating the BV
• Removing the BV entirely
• Reseating the Bill Box (figured, why not?)
• Removing the Bill Box entirely
• Reseating the Power Supply
• Reseating the Printer
• Removing the Printer entirely
• Reseating the cables related to the VFD
• [/l][/l]

If the display is saying netplex link down then the display is faulty or the harness is damaged. Netplex link down is not a machine error its a display error. That error is will show even if the display is powered up not connected to the machine.

From the original post:

... Instead, it eventually goes blank after about 20-30 seconds (it does NOT display a NETPLEX error) ... Reseating the MPU board (while it is disconnected the VFD will show a NETPLEX error after the self test)

You can try replacing the vfd or its driver if you have a 2 piece vfd.

I am looking into what spares to get, thanks.

Peace!

-=- James.
[/list]

[Tilt]

A bad MPU board can also cause a NO DISP error.

[jtwine]

A bad MPU board can also cause a NO DISP error.

Thanks.  A replacement board is one of the things I am looking into, maybe even moving to an enhanced with a matching backplane if possible.


Peace!


-=- James.

[Stayouttadabunker]

This clue you pointed out...>>>"BV can be heard "twitching" every few seconds" makes me think something is wrong with the MPU board as well.


But there's no getting around that you will have to learn how to fully navigate the settings to get your machine up and running again when you replace the board and swap the chips....make sure you get a clear and key chips to help get it going.

[jtwine]

This clue you pointed out...>>>"BV can be heard "twitching" every few seconds" makes me think something is wrong with the MPU board as well.
But there's no getting around that you will have to learn how to fully navigate the settings to get your machine up and running again when you replace the board and swap the chips....make sure you get a clear and key chips to help get it going.

Thanks for that.  Makes me feel better about going after a replacement board. 
I have a full set of Key and Clear/IVC chips and have used both before on this machine.  I am pretty sure I can find a document somewhere that would allow me to blindly navigate the menus/process for what I need to do to recover from an RAM ERROR tilt, just in case the replacement board does not automagically detect the display on its own.


Peace!


-=- James.

[Retro tech repair]

This clue you pointed out...>>>"BV can be heard "twitching" every few seconds" makes me think something is wrong with the MPU board as well.


But there's no getting around that you will have to learn how to fully navigate the settings to get your machine up and running again when you replace the board and swap the chips....make sure you get a clear and key chips to help get it going.

clear and key should not be needed after board swap. processor board id miss match is cleared the same as ram error after changing a battery.