S2000 super board problem

[Badbaud]

The machine was totally dead so I swapped out the power supply and it powered up with a "displays netplex down" so I replaced the low RAM battery and the dead Varta battery.
I got the same error message so I re-seated both I/O boards and all of the connectors on the display section plus the back plane connectors.
I still get the same error message.

Any suggestions on what is causing this stubborn message?
Could a key 17 be used to clear the board? Would that help?

See attached image of the board.

[cowboygames]

That enhanced MPU requires a key 45 and clear 224. And unless you have a reason not to, remove the varta battery and cut the legs on transistor U16.

[Ken]

Do as Cowboy mentions about removing the varta and U16 on all 1270 boards for home use.

To the best of my memory and after the varta and U16 is removed --

When the netplex link is down message displayed in the VFD.

Red LED on board and Message in VFD both flash = Board Issue - Replace Board

Solid Message in VFD = Replace Power Supply

[cowboygames]

That's part of why I said ditch the varta. A low voltage or faulty circuit on that throws a netplex error on 1270 boards

[Badbaud]

Thanks for the advise. I hope it is a bad Varta circuit and not the power supply - the display is on solid and no blinking lights - BUT just in case it is a power supply issue what causes this problem with the power supply?
I have caps and some chips for the power supplies and am not scared about stripping it down to the board and replacing suspects.

[Ken]

Caps are the most likely cause with those power supplies for IGTs. I think Happ might have a kit on their site but doubt they are going to tell which caps are in the repair kit.

[Retro tech repair]

this seems to be a common subject so maybe i will make a thread dedicated to it at some time. so im going to explain the "displays netplex down" error. this error is not an error that is related to the mpu or power supply at all. that's not to say it cant point to a problem with either but it can be misleading to assume that because a always b. the "displays netplex down" is the vfd telling you that it cant communicate to the mpu. over the past 6 years and well over 100 s2000s worked on i have seen a lot of different causes of this problem so i will list the most common below.

blinking error with all light on mpu solid but red blinking - i have only ever seen this on 1270 boards. the red light flashing means that the board is being held in reset. the most common causes of this is a fault in the varta circuitry or a problem with one of the spartan chips.

solid error with "no disp" shown on the credit display - this i have seen with both type board and is almost never a fault with the mpu. the fact that you are getting "no disp" on the credit display means that the mpu has fully loaded and cant see the vfd. this means that it is some kind of communication problem between the vfd and mpu. common causes of this is bad vfd controller, harnes damage - wire unplugged, another device on netplex with a short accost one of the data lines this would be the bill validator or printer, in very rare cases a fault on the motherboard or mpu.

solid error with nothing on the credit display - with this form of the error it normally means the mpu is not booting. the most common cause of this is a faulty power supply, but i have also seen it caused by bad mpu or motherboard, and any other part that may have a direct short between one of the voltage lines to ground.

[Badbaud]

Doing the Varta mod didn't help.
Maybe there is a clue on the board's LED lamps.
This is what I get on the lamps from top to bottom.
green on
green on
nothing on
nothing on
yellow on
yellow on
green on
nothing on

[Retro tech repair]

Does the bill validator or printer try to cycle. Also check the fuses on the motherboard.

[Ken]

Now that the mod is done.

LEDs are normal for initial power on. If the machine could boot up then the lower 3 will go off after netplex check and be ready. Currently it can't get that far in the boot up process.

Did you try a different power supply or replace the caps on the current power supply?

[Badbaud]

I am going to tackle the power supply on Monday.
The BV does cycle.

The machine came in totally dead so I pulled a unknown, but same model, power supply off the shelf.
That one allowed power up but got me stuck at this point.

[Badbaud]

The power supply, the original dead one was a mess inside, I found a botched attempt at replacing caps with cold solder joints and open traces.
Great board work "somebody" out there in repair land.
But that is my personal white whale - and belief that some people should not get within 10 feet of a hot soldering iron.

Anyways, I took a power supply out of a working machine that had a super board in it also, but had no glass, no coin acceptor, and no BV harness, and the "display neplex down" went away and the game is now in perfect working order.
Thanks for everybody's help.

[Ken]

Awesome ..