(Topic ID: 214257)

Sttng switch matrix flickering issue I NEED HELP


By Okarcades

1 year ago



Topic Stats

  • 45 posts
  • 11 Pinsiders participating
  • Latest reply 1 year ago by Cycloneman
  • Topic is favorited by 1 Pinsider

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#1 1 year ago

So I picked up a Star Trek The Next Generation a few weeks back and finally got it up and running! I still can't get it to start a game yet. I rebuilt it he 12v section and it's giving me solid out put. 11.98 regulated and 13.95 under regulated.

All optos seem to work although the few in the video are acting strange and flickering.

When activating the another switch in another column or row the flicker also does goes to that switch.

Totally weird.

Any one have any insite?

#2 1 year ago

Your switch matrix may be on the way out, or your switch plugs/pins may be dirty. If this is an old game that wasn't working, is there battery leakage on the MPU?

#3 1 year ago

I would jumper from columns and rows and narrow down the problem to cpu or playfield.

http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Switch_Matrix_Problems

#4 1 year ago
Quoted from Okarcades:

So I picked up a Star Trek The Next Generation a few weeks back and finally got it up and running! I still can't get it to start a game yet. I rebuilt it he 12v section and it's giving me solid out put. 11.98 regulated and 13.95 under regulated.
All optos seem to work although the few in the video are acting strange and flickering.
When activating the another switch in another column or row the flicker also does goes to that switch.
Totally weird.
Any one have any insite?
» YouTube video

Battery leakage damage, almost certainly.

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com

#5 1 year ago

There is a new rottendog mpu so it can't be corrosion.

I do have another mpu I can try but it is also rottendog

#6 1 year ago

Find the opto board and check for cracked header solder joints.

#7 1 year ago
Quoted from Borygard:

Battery leakage damage, almost certainly.

Quoted from Okarcades:

There is a new rottendog mpu so it can't be corrosion.

Not true - listen to Borygard.
The corrosion could have spread to the contacts of the wire harness and/or the IDC connections of the connector at the wire.
This screams corrosion related contact issues.... or bad IDC connections.
While in test; wiggle the wire harness at the connection(s) (at CPU board) to see if they flickering changes. Examine the contacts of the IDC connector to make sure they are clean and shiny.

Quoted from GRUMPY:

Find the opto board and check for cracked header solder joints.

since this seems to be related to a specific row; I'd be more inclined to believe this is a connector or a power issue to the row.

#8 1 year ago

I have already reflowed the entire opto board and no change -

Quoted from Zitt:

Not true - listen to Borygard.
The corrosion could have spread to the contacts of the wire harness and/or the IDC connections of the connector at the wire.
This screams corrosion related contact issues.... or bad IDC connections.
While in test; wiggle the wire harness at the connection(s) (at CPU board) to see if they flickering changes. Examine the contacts of the IDC connector to make sure they are clean and shiny.

since this seems to be related to a specific row; I'd be more inclined to believe this is a connector or a power issue to the row.

I will check all connectors next. Good idea!

#9 1 year ago

Connectors on MPU looks great but I still cleaned them off with some isopropyl alchol and no change at all.

now what!

#10 1 year ago
Quoted from Okarcades:

Connectors on MPU looks great but I still cleaned them off with some isopropyl alchol and no change at all.
now what!

Swap CPUs with another WPC game to confirm/rule out the CPU as the problem.

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com

#11 1 year ago
Quoted from terryb:

I would jumper from columns and rows and narrow down the problem to cpu or playfield.
http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Switch_Matrix_Problems

Did you do this to isolate the issue?

#12 1 year ago
Quoted from BriPin:

Did you do this to isolate the issue?

I haven’t done that yet

Quoted from Borygard:

Swap CPUs with another WPC game to confirm/rule out the CPU as the problem.

I will do that first and then test the matrix second

#13 1 year ago

try replacing an opto and see if it stops flickering. It is fairly common to have a weak opto or two on an older game. However if they are all doing it i would suspect connector/corosion issues.

#14 1 year ago

Cleaned Connectors & Replaced MPU with another new Rottendog -

Now I will attempt to unplug the connectors and isolate the issue, I cannot seem to get any of the row 9 switches to show up on the switch test! Not sure if that is an issue or just doesn't show up because there are so many switches in this game.

Can anyone shed any light on this for me?

#15 1 year ago

A) Double check and make sure the connector is not one pin off.
B) Repin your connectors. They seem to be causing trouble. It's time consuming, but not difficult, and then you'll know for a fact you have good connectors.

#16 1 year ago

- Repinned the connectors. Nothing changes.

- Unplugged the row connector off the mpu and through a diode in. When plugged into the offending row (green/white) and I touch any of the pins on the mpu the 3 optos do the same thing (flash) on a different row. If I put the diode into a different plug on connector then the problem goes away on all rows! Which leads me to belive it is not an mpu issue and it has something to do with playfield wiring.

- I replaced every diode on every switch on the green/white row.

- I unplugged the green and white from the through board. The other 2 optos still flash.

- I plugged the connector with green/white off the 16 opto board and the opto flash on the trough.

- I checked ever plug and reseated. With that color

- I figured the optos could have gotten a power surge and blown them out so I swapped some optos on the trough and still no change!

What the heck else can I check?!?!?

#17 1 year ago
Quoted from BriPin:

Did you do this to isolate the issue?

It has to be playfield after the list above

#18 1 year ago
Quoted from Okarcades:

Cleaned Connectors & Replaced MPU with another new Rottendog -
Now I will attempt to unplug the connectors and isolate the issue, I cannot seem to get any of the row 9 switches to show up on the switch test! Not sure if that is an issue or just doesn't show up because there are so many switches in this game.
Can anyone shed any light on this for me?

You mean column 9, and it's run through the Aux 8 board in this game, not the CPU.

Ignore column 9 for your issue.

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com

#19 1 year ago
Quoted from Borygard:

You mean column 9, and it's run through the Aux 8 board in this game, not the CPU.

Ignore column 9 for your issue.

I figured that out! It's under gun settings

#20 1 year ago
Quoted from Okarcades:

...
- Unplugged the row connector off the mpu and through a diode in. When plugged into the offending row (green/white) and I touch any of the pins on the mpu the 3 optos do the same thing (flash) on a different row. If I put the diode into a different plug on connector then the problem goes away on all rows! Which leads me to belive it is not an mpu issue and it has something to do with playfield wiring. ...

You need to remove ALL switch matrix connectors from the MPU. Otherwise you're not isolating the CPU, the playfield switches will still influence any testing.

Put the game into switch edges test, then remove ALL of the 0.100 connectors from the bottom of the CPU. THEN do the test with the jumper.

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com

#21 1 year ago
Quoted from Okarcades:

Cleaned Connectors & Replaced MPU with another new Rottendog...

So what result did you get? Same as the previous board?

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com

#22 1 year ago
Quoted from Borygard:

so what result did you get? Same as the previous board?

Yes same results

#23 1 year ago
Quoted from Borygard:

You need to remove ALL switch matrix connectors from the MPU. Otherwise you're not isolating the CPU, the playfield switches will still influence any testing.

Put the game into switch edges test, then remove ALL of the 0.100 connectors from the bottom of the CPU. THEN do the test with the jumper.

--

Ok I get it now! I'll do that and report back

#24 1 year ago
Quoted from Okarcades:

Ok I get it now! I'll do that and report back

No need. You put in a different CPU and got the exact same issue. Unless both boards are bad with EXACTLY the same problem (very, VERY, unlikely) it's not the CPU.

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com

#25 1 year ago

So what would you suggest I do next

#26 1 year ago

Also,It's very possible the previous owner may have done some work under the playfield such as replacing a switch,diode,ect. Replacing a switch and rewiring it in the wrong order or putting a diode in the wrong way can cause these types of problems.It can be a real pain in the ass to track down,Since you ruled out the CPU the next best thing to do is look into the switches and diodes,check wiring/color of the wires placed on the switches in the right order,test diodes on the switches for faulty/bad/shorted diodes.The switch matrix in the manual is your best friend in these type of problems.Work your way up the daiseychain of wiring in the column and row of the chart.

#27 1 year ago

I check out a few more things. Before I start I still haven’t had a chance to test the board anymore thoroughly but this lead me to my first idea.....

1. The ASIC chip was slightly damaged upon removal from a switch to board to board. One of the legs on the corner was bent so I just bent it back. Maybe that loose leg is causing intermittent issues. Not sure so I ordered a new one.

2. After reading Pinwiki they state that sometimes the c2 capacitor goes out on the driver board and causes and issue with the lm339 chip. I then noticed that there are lm339 chips on every opto board so I ordered a pile of those too so I can replace them and all the opto boards and driver board. I doubt it will fix the problem but it’s worth a shot. I have a pretty awesome desoldering gun so I know I can do the repairs safely.

Anyone else have any ideas or theories?

#28 1 year ago

I would seriously consider verifying the harness assembly for that row.

#29 1 year ago
Quoted from Zitt:

I would seriously consider verifying the harness assembly for that row.

I've traced the whole thing! The only thing I can't figure out is the green/white ends at the 16 opto board. And on the matrix it is only half way through. Although it branches off earlier.

I've check ever switch, check every plug, Traced every inch of wire and replace every diode. What else is there.

#30 1 year ago
Quoted from Okarcades:

I've traced the whole thing! The only thing I can't figure out is the green/white ends at the 16 opto board. And on the matrix it is only half way through. Although it branches off earlier.
I've check ever switch, check every plug, Traced every inch of wire and replace every diode. What else is there.

Is the game still doing the same thing or did more problems pop up

#31 1 year ago

Same thing no more no less

#32 1 year ago
Quoted from Okarcades:

Same thing no more no less

Man,Not a lot options left..

#33 1 year ago
Quoted from Okarcades:

The only thing I can't figure out is the green/white ends at the 16 opto board. And on the matrix it is only half way through.

The switch matrix only shows electrical connections, it in no way represents the wiring sequence for the switches.

#34 1 year ago
Quoted from Pin_Guy:

The switch matrix only shows electrical connections, it in no way represents the wiring sequence for the switches.

Well dang! I'm lost then!

#35 1 year ago

You wouldn't happen to have a logic probe, or better yet, an oscilloscope would you?

#36 1 year ago

I have a logic probe but my knowledge is very limited on how to use it

#37 1 year ago
Quoted from Okarcades:

I have a logic probe but my knowledge is very limited on how to use it

https://pinside.com/pinball/forum/topic/terrybs-guide-to-logic-probes

#38 1 year ago

WOW. terryb This is the first time I looked at your guide to logic probes and what a great guide it is; I'm a couple years late, but thanks for taking the time to creating this guide for folks to use.

1 week later
#39 1 year ago

I replaced the lm339 chip and the capacitor before it. I'm convinced it is not a board issue now. We are going to rip the entire playfield down and shop it and see if we can find something else hidden.

I will report back after that!

#40 1 year ago

I replaced the capacitor on the 16 opto board and I think I have it fixed! I have the whole top of the game torn off to shop it but I believe it’s fix now.

Under the capacitor was leaking and I had to clean the heck out of it before solder would stick. I think it’s good to go but I will report back as soon as I am sure. Thanks for all the help.

#41 1 year ago
Quoted from Okarcades:

I replaced the capacitor on the 16 opto board

So this was a bad cap on the powersupply on the Opto Board?
That's interesting... Good learning if true.

#42 1 year ago
Quoted from Zitt:

So this was a bad cap on the powersupply on the Opto Board?
That's interesting... Good learning if true.

Yes! Totally weird

#43 1 year ago
Quoted from Zitt:

So this was a bad cap on the powersupply on the Opto Board?
That's interesting... Good learning if true.

how could you really be sure its working since you have the whole playfield stripped apart?Im just curious not that i dont believe you

#44 1 year ago
Quoted from Cycloneman:

how could you really be sure its working since you have the whole playfield stripped apart?Im just curious not that i dont believe you

He showed during his video above that a whole row of optos was randomly flickering while in switch test.
While it's not conclusive proof yet; I suspect he's probably right as an unfiltered opto rail would appear to the cpu as pulsating like the video showed.
I'm sure he'll confirm it's fixed for sure once he has the machine back together.

#45 1 year ago
Quoted from Zitt:

He showed during his video above that a whole row of optos was randomly flickering while in switch test.
While it's not conclusive proof yet; I suspect he's probably right as an unfiltered opto rail would appear to the cpu as pulsating like the video showed.
I'm sure he'll confirm it's fixed for sure once he has the machine back together.

oh now i see what your saying i watched the video again.i'm glad he found the problem

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