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A plea for suggestions.... Machine reset.

JMP

JMP

Registered
10 Years
Joined
Aug 12, 2011
Messages
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Location
Lancashire
My infamous ToM has been resetting for a while now (almost since it arrived), sometimes occasionally, sometimes immediately at switch on and repeating it over and over... Myself and Luke have gone through virtually all the boards to try and pin down the problem to no avail, so far:

- Swapped power driver board out with a known good one from my WW and problem remains although less frequent (at moment). Voltage tests read fine with no spikes/drop outs. Have tried forcing reset with mad use of flippers etc. but makes no difference.
- Swapped out CPU board with a good one provided by Phil at PH and problem remained.
- Updated game ROM with latest V1.3 software, no difference.
- Disconnected other boards (DMD driver, sound and fliptronics) one at a time and still resets (this includes a brand new DMD driver board).
- Tried tapping connectors (many on board sides have already been replaced) and cannot force the reset this way either.

As there appears no trend/regularity to it, I'm now thinking the power supply to all the boards themselves; the wiring, the transformer?

Really struggling here now, any suggestions folks? Thanks.
 
If you've gone through all the boards then check the wiring back to the transformer, the transformer itself and then the wiring out to the plug, there's got to be something thats causing the voltage to drop out and make it reset.
 
ensure the pins of the main 5volt connector at the cpu board are ok,I know Andy has fixed a few due to that connector.I also once had a dmd dragging it down.Same on the connector for the 5volt on driver board

I know that is rare but try another dmd.

I assume your line voltage is ok - ie 230-240 volts
 
Thanks... We've had two CPU boards in it now, I can try replacing the connector at the end of the wires to that and the driver board though. It's had two different DMD driver boards and DMD's in it too. Currently has a brand new display driver board in it and it still resets when both disconnected. Thanks anyway.

As above from Ronsplooter, think priority for now is wires from the rear socket all the way through to transformer onwards... Doesn't appear I have a compatible transformer in my other games to swap out and try unfortunately.

Just wish this thing would reset constantly to help pin it down. When it plays for an hour or so we think we've cracked it...:mad:

As an after thought, think I'll try plugging into another socket in the house too.... House has been rewired 18 months ago but you never know....

Cheers for now.
 
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The only thing that can cause a reset is the watchdog isn't it? And the criteria for that is for the 5v line to be pulled low, could Luke put a scope on the 5V line and capture the output?
 
Try changing the flipper button pcb's/check the wiring/connector there too..!

I've known these reset games before now.
 
Carl Spiby said:
The only thing that can cause a reset is the watchdog isn't it? And the criteria for that is for the 5v line to be pulled low, could Luke put a scope on the 5V line and capture the output?
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First thing checked Carl. The voltage reads correct every time with no peaks or lows being registered....
 
Moonraker said:
Try changing the flipper button pcb's/check the wiring/connector there too..!

I've known these reset games before now.
Click to expand...

Thanks will give that a try. Open to anything at the moment to keep my sanity !
 
Carl Spiby said:
So the scope just shows a steady line even when the machine spontaneously resets? How odd :confused:
Click to expand...

Uses a multimeter that displays highs and lows of a voltage reading over time and each time shows nothing unusual.... You're right, it's really wierd.
 
I have no technical grounding to be suggesting this, but, maybe you need something with a higher sample rate because a meter might not catch the split second dip it takes for the watchdog to intervene?
 
JMP said:
Uses a multimeter that displays highs and lows of a voltage reading over time and each time shows nothing unusual.... You're right, it's really wierd.
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You're really going to need a scope to nail this. Something is pulling the 5v down.
Are you sure that the power driver board you put in was hunky dory ?
 
You could also try swapping the ribbon cables. Cause all sorts of problems those buggers.
 
Don't do anything else until you have replaced the connector at J114 on the power board, and ideally the pins. At the least you should clean the outer edge of the pins with fine emery paper. This cures 95% of reset problems, so if you haven't done this yet, you are working through the many things that make up the remaining 5% of reset problems.
 
pinballmania said:
Don't do anything else until you have replaced the connector at J114 on the power board, and ideally the pins. At the least you should clean the outer edge of the pins with fine emery paper. This cures 95% of reset problems, so if you haven't done this yet, you are working through the many things that make up the remaining 5% of reset problems.
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Thanks Andy, the board side pins of this connector have already been replaced on the original board (going to pick up tonight so will double check). As resets have occurred with two different power boards including this one, will change the wire end connector too (which is original) to make sure. We tried tapping J114 to force a reset but it didn't. Luke may have a 7-pin one but can I order a batch of connector sizes from you as currently out of these, thanks. I have the push-tool already.
 
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Andrew Stockdale said:
You're really going to need a scope to nail this. Something is pulling the 5v down.
Are you sure that the power driver board you put in was hunky dory ?
Click to expand...

I'm told the time logging multi-meter works the same...!? Yeah, the second power driver board is from my WW which has been working fine for months. Going to replace the wire end of connector J114 now too anyway to be sure.

You could also try swapping the ribbon cables. Cause all sorts of problems those buggers.
Click to expand...

Already got brand new ones fitted, thanks anyway.
 
Hi everyone, I'll just throw in some information on what we have done.

1) The first thing I tried was connecting a data-logging 80,000 count true RMS meter onto a chip on the CPU board. It was reading 4.936vdc solid with no fluctuation. The RMS AC ripple is between 5-20 milliamps, which is far lower than the board "should" be able to handle. I am confident in this meters ability to capture glitches as I have successfully used it to do so many many many times before. 9 times out of 10 when I see this problem, the dcv fluctuation and / or high AC ripple is significantly out of spec and the probably can be quickly tracked down to drvier board regulation.

2) I aggressively prodded and wiggled power related cables inside the backbox with absolutely no affect on the voltage read at the CPU board. Again usually a bad connection is easily detectable here.

3) Rapidly firing both flippers has absolutely no affect on the voltage read at the CPU board, not even 1 millivolt! Coil current draw dropping the 5v line is a clear indicator of power issues further upstream, but this is not the case. Yet again, 9 times out of 10 this is easy to spot.

4) I poked the ASIC and the CPU board went a bit mental, so I repaced the ASIC socket and cleaned the ASIC legs. The CPU board no longer has a problem with the ASIC being poked, so that problem has been isolated and removed.

5) I already replaced the power related pin headers on the driver and CPU board at a very early stage when I was repairing this machine.

6) CPU board was swapped and the reset continued

7) All other boards were disconnected and the reset continued

8) Driver board was swapped and the reset continued.


It's really looking at being issues with the internal cables at this stage. I've not tried monitoring the power with the White Water driver board yet, so maybe I should do that first just in case that is a factor since swapping it.

I'm really wondering if it could be data cables as although I am not saying I can't be proven wrong, but I could not be more confident that the ToM driver board is putting out solid 5v without any doubt. I have the driver board here now and it is rock solid on the bench scope even when applying a variable frequency load.


Remember folks .... this is the BEST Theatre of Magic Tobin has ever seen!
 
Carl Spiby said:
Does ambient temperature have anything to do with how much it resets, i.e. is it worse when its cold?
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It seems not.

I've seen it start resetting immediately from cold power on, or it can play for an hour then start resetting, then it can go back to working for an hour.

Absolute nightmare to track things like this down when it appears not to be affected in any sensible way by time/temperature/load/vibration
 
FYI I am going to re-pin the power connectors on the backbox wireharness, and I also suggest that John might want to try swapping the ribbons (despite them being new) just to test

(Also don't let Mr Foster plug your data cables in upsidedown :) :) )
 
Thanks for the updates. Always good to hear what has been tried to cure faults. It all goes in the mental fault log.
 
OK, so tonight's developments.... Haven't got wire connector for J114 yet so just pushed home all the wires with insertion tool. Worked for half an hour then reset again (I'm still going to replace this when have the connector). Disconnected and re-seated all big connectors to/from transformer and fuse box and then it wouldn't boot other than a few dots showing on the display.... A-ha ! Disconnected and re-seated these connectors again and made sure all connectors pushed home on boards in backbox and it booted again, worked for 20 minutes and then reset.

So... anyone know where to buy new made up connectors/wiring or maybe just the connectors? Will email Andy....
 
Carl Spiby said:
What the difference in measured voltage between the 5V test point and the pin 2 of the game ROM?
Click to expand...

Sorry Carl, was waiting for Luke to answer you but appears he's back in Pinball Info hibernation. ;)

Amazingly, tonight I cleaned the connector pins and re-seated wires in connectors J101, J102 & J104 on power driver board and appear to have solved it.... can't quite believe it after weeks of going round in circles. :confused: Thanks all for the help.
 
Well I ain't convinced yet, but an hour and a half of play with no reset is promising so far... Either way, something else is sure to come along soon, always does with this machine. :rolleyes:
 
As an aside, it is certainly possible to have a dip on the +5v momentary enough to reset or halt a microprocessor that you would never see on a multimeter. You would need a digital storage oscilloscope with at least 20MHz sampling.

Anyway, hope you've fixed it now.
 
It is !! Can't quite believe down to one of three 'other' connectors after all this time.... Deja-vous to the fuse experience !! :confused:
 
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