(Topic ID: 161261)

No Fear / WPC resetting woes.


By Frax

3 years ago



Topic Stats

  • 66 posts
  • 20 Pinsiders participating
  • Latest reply 3 years ago by Frax
  • Topic is favorited by 8 Pinsiders

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There are 66 posts in this topic. You are on page 2 of 2.
#51 3 years ago

What is the voltage measuring across C31 on the MPU?

#52 3 years ago
Quoted from PinballManiac40:

What is the voltage measuring across C31 on the MPU?

I looked at that before I pulled the board. Not sure I measured it right, honestly. One side of the cap (red lead to black lead in ground braid) read .03 volts lower than the test point on the driver board...the other side read 0 volts? I'm not real up on my theory of electronics here, but obviously that's not an accurate reading.

#53 3 years ago

I knew you'd get it! 4 days later, and bam, all is looking good for you!

#54 3 years ago
Quoted from Frax:

I looked at that before I pulled the board. Not sure I measured it right, honestly. One side of the cap (red lead to black lead in ground braid) read .03 volts lower than the test point on the driver board...the other side read 0 volts? I'm not real up on my theory of electronics here, but obviously that's not an accurate reading.

VDC shown as V== on most multimeters.
With power on
To measure across C31, you can just put the black lead on the C31 - (which is ground) and the red lead on C31 + side.

I hope that is not confusing.

Just was hoping to see after you had the driver and MPU boards back in to see if all the work you did do that you now have a higher voltage at C31 on the MPU. If you're at 4.95volts or higher, I would not expect any more resets.

#55 3 years ago

Jesus christ, it never ends. Stayed up for an hour or so, survived a few games, no resets....then it reset, and never came back on. No idea why. Finally said "F IT!" and pulled the WCS board. Since the game wasn't even booting past the blanking circuit, I pulled the 68B09 CPU from WCS..... now the game is working just fine again and played another 20 minute game.

Guess I'm going to be ordering a CPU chip now. SMH...

#56 3 years ago
Quoted from Frax:

Jesus christ, it never ends. Stayed up for an hour or so, survived a few games, no resets....then it reset, and never came back on. No idea why. Finally said "F IT!" and pulled the WCS board. Since the game wasn't even booting past the blanking circuit, I pulled the 68B09 CPU from WCS..... now the game is working just fine again and played another 20 minute game.
Guess I'm going to be ordering a CPU chip now. SMH...

Though, still need to know if the problem is related to voltage or not. What do you measure across C31 when the game resets?

Ribbon cables can also cause a MPU not to boot up.
Normally if a game does not boot, but has 4.9 volts or better on C31 of the MPU, unplug the ribbon cable from the MPU board. If the board then boots, reseat the ribbon cables at all the connections.

#57 3 years ago
Quoted from PinballManiac40:

Though, still need to know if the problem is related to voltage or not. What do you measure across C31 when the game resets?
Ribbon cables can also cause a MPU not to boot up.
Normally if a game does not boot, but has 4.9 volts or better on C31 of the MPU, unplug the ribbon cable from the MPU board. If the board then boots, reseat the ribbon cables at all the connections.

It's 4.88 with the WCS board in there across the cap. Everything was unplugged when it wasn't booting aside from the power connector to the CPU board. For whatever reason, that CPU chip apparently just decided to up and die....guessing it was on it's last leg already and finally gave out. It's not that the other things weren't (aren't?) contributing, but just swapping the 68B09 got it to boot up perfectly again.

Going to let it sit for a bit, then put the No Fear driver board back in, which had higher 5v line on it anyways.

#58 3 years ago

If you still have 5.02 or so volts on TP2 of the driver board then it is still looking like your voltage is too low at the C31 on the MPU and causing the resets. I mentioned early on in the thread that if the voltage gets down between 4.7 to 4.75 volts, the game will never boot. You're in the gray area with 4.88 volts so you're seeing intermittent boot up.

To bad you don't have another game to test the MPU in to prove it is good.

Have you changed out any of the J210 and J114 male connectors and the female wired connectors? I think I may have overlooked the answer to this.

#59 3 years ago

I think you're overlooking what I'm saying, not a solution. 5.02 volts was with the NF driver board. The WCS board, which is what is in the game and I've been trying to get the game stable with, has lower voltages coming from the 5v section.

The game is stable now. Voltages be damned. The voltages, even when it refused to boot, was NEVER as low as 4.75 volts. I checked. The resets were being caused by the cracked ASIC socket and apparently a dying CPU. There's no amount of connector work that's going to magically make the driver board generate more volts than what is at the 5v test point on the driver board. I was only losing .03 volts from the test point to the cap on the CPU. WCS has never, ever, reset in the way that No Fear has been, so 4.88 might be borderline, but with the power supply in my condo...not a dealbreaking issue.

THAT SAID... J210 header and connector have been repinned. J114 has not. The WCS driver board works fine in WCS, and I'm not going to do unnecessary work to a functioning board. The voltages on the No Fear driver board are higher, and losing .03 volts is totally negligible there.

#60 3 years ago
Quoted from Frax:

The voltages, even when it refused to boot, was NEVER as low as 4.75 volts.

I was only commenting that 4.75 at that MPU it too low of a voltage for the game to boot. Experience working on these games is where I learned this.

Quoted from Frax:

The resets were being caused by the cracked ASIC socket and apparently a dying CPU.

Did you test this CPU chip in the other MPU board? Same result? I don't think CPU chip failures are very common.

Quoted from Frax:

The WCS board, which is what is in the game and I've been trying to get the game stable with, has lower voltages coming from the 5v section.

Now that is very clear. I'll leave this with others to help from here.

#61 3 years ago
Quoted from PinballManiac40:

Did you test this CPU chip in the other MPU board? Same result? I don't think CPU chip failures are very common.

I second this...if you're hoping a new cpu chip is the ticket you may be disappointed. This is most probably a power issue. Also power could be good at TP yet something will make it momentarily drop (ex: hitting both flippers at the same time) which then triggers the reset by the watchdog circuit.
Here's some light reading:

https://pinside.com/pinball/forum/topic/wpc-reset-my-voltage-is-55v

#62 3 years ago
Quoted from PinballManiac40:

Now that is very clear. I'll leave this with others to help from here.

Alright, thanks.

#63 3 years ago
Quoted from kvan99:

I second this...if you're hoping a new cpu chip is the ticket you may be disappointed. This is most probably a power issue. Also power could be good at TP yet something will make it momentarily drop (ex: hitting both flippers at the same time) which then triggers the reset by the watchdog circuit.

I guess we'll see, won't we. I just played a 7 billion game, got to the wizard mode, and had six other multiballs and sliding the machine around on my floor like crazy....no issues at all.

Think it's funny you guys are all so obsessed on the power issue that you're completely ignoring what I'm telling you. For all any of us know, I'm walking around in my socks, touched something when sitting down to examine the board and chips, and popped the microprocessor via static. Facts are facts though, and the game seems pretty damn solid right now. When I have a party after cleaning this thing up and I start getting resets on WCS (since the voltages will be lower on there) and 4 games running off the same outlet, then yeah, I'm probably going to have to do something about the "borderline" voltages on this driver board.

Game has been running for an hour and a half now, no resets...but it's probably the power supply keeping it from booting...other than it's booted and playing now and nothing changed aside from the microprocessor. -_-

#64 3 years ago

Well..if it is then this thread will be a good troubleshooting tip for others in the future...good luck, I hope this is the last time you have to deal with this.

#65 3 years ago

Me too...game's still up...time to try putting the original board back in there.

*edit* Original driver board back in the game now. Solid 5V *exactly* at the cap. 5.03v on the TP2 on driver board.

#66 3 years ago

Game was up for several hours last night with no issues... I'm marking this thread resolved unless something else comes back up.

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