Row of Switches out on WhiteWater

Currently trying to trouble shoot my row of switches that are out on my whitewater. (18,28,38,48,58,68,78,88) WHT -GRY

I have tested continuity from the board to each switch affected and it showed continuity there on my multimeter.

Did the jumper test and when I connect the affected pin on J209 to any pin on J207 nothing happened. I tested all other pins on J209 with J207 and all appropriate switches fired.

Next I tested continuity from the affected pin on J209 to U19. My multimeter didn't make a sound but the multimeter went from the reading of 1 to 1944. Does this mean there is a solid connection there or is this my problem?

Also I'm being told the next step is to purchase a Logic probe. Not sure how complicated the next step in troubleshooting is. Am I better off just buying a new rottendog WPC98 MPU?

Any advice is appreciated.

Thanks,

Pete

#2 8 years ago

ZAZ

zaza

Pinside+ Frequent

The input goes from J209-9/ J208-9 through D10, through R65 (1K) to U19-7 so you won't find a solid connection between those points.
Measure from component to component seperate.

If U19 if the problem, replace it or let it replace by a tech.
J209-_to_U19_(resized).png

#3 8 years ago

PMM

Pmaino

Pinside+ Frequent

Ok I checked continuity for each section. All tests are good. What would you test next?

#4 8 years ago

PMM

Pmaino

Pinside+ Frequent

I tested continuity from the 8 pin on the U19 to the R34 and didn't get a connection. Should I be getting a connection?

#5 8 years ago

ZAZ

zaza

Pinside+ Frequent

OP
Quoted from Pmaino:
I tested continuity from the 8 pin on the U19 to the R34 and didn't get a connection. Should I be getting a connection?

No, R34 is connected with the exit of U19

You don't need a logic probe to test U19, I will give a step by step guide:

-machine 'ON' and go into test menu T.1
-unplug J206,207,208,209 on CPU board
- DMM in DCvolt and measure :
BLK pen on GND, RED pen on U19-7 , should be 12Volt
BLK pen on GND, RED pen on U19-1 , should be 5Volt

Put a jumper from GND to J209-9 and measure again,
BLK pen on GND, RED pen on U19-7 , should be 0.7Volt
BLK pen on GND, RED pen on U19-1 , should be 0.1Volt

see picture
test_U19_1-2-3_(resized).png

#6 8 years ago

PMM

Pmaino

Pinside+ Frequent

Ok here are the readings I got.

1. U19-07 11.87V
2. U19-01 4.87V
3. U19-07(jumper) .72V
4. U19-01(jumper) .02V

Would you consider these normal readings?

If so what else would you check?

#7 8 years ago

ZAZ

zaza

Pinside+ Frequent

Yes, that is what the voltages should be.
When you put a jumper from ground to J209-9, gave it a "row short" in DMD ?
If not, the problem is deeper into CPU-board and next to check are trace to/and U13.
Can you measure continuity from U19-1 to U13-8 (black line in picture)
Crossing battery-pack so battery damage maybe ?)
U19_-_U13_row8_(resized).png

#8 8 years ago

PMM

Pmaino

Pinside+ Frequent

When I grounded J209-9 I did not get a "row short" in the DMD.

Continuity from U19-1 to U13-8 was good.

Here are a few pictures of the board. Maybe battery/board damage?

image_(resized).jpeg

#9 8 years ago

ZAZ

zaza

Pinside+ Frequent

OP
Quoted from Pmaino:
Maybe battery/board damage?

Yes, that could be one of the causes. maybe bad connection in socket U13

do you have continuity between U13-12 and U14-13 (D7) ? (red line)
U13_-_U14_D7_(resized).png

#10 8 years ago

PMM

Pmaino

Pinside+ Frequent

Yes there is continuity from U13-12 to U14-13.

#11 8 years ago

ZAZ

zaza

Pinside+ Frequent

Well, you could do the same as U19 with puttin a GND to J209-9 but now measure U13.
U13-8 should toggle between 0.1 and 5.0 Volt with and without GND

U13-12 (D7) is different because here starts the hi-freq data signal so you need other equipment.
With standard multimeter it would read between 3.7 and 0.1 Volt.

You could try another 74LS240 since it is already on a socket

#12 8 years ago

PMM

Pmaino

Pinside+ Frequent

I'm starting to think I might need to buy a new Rottendog MPU board. Let me test the U13 and see what I get but I'm thinking the issue lies deeper on the board and I don't have the equipment to test.

#13 8 years ago

PMM

Pmaino

Pinside+ Frequent

Ok voltage is good on U13-8 with and without the jumper.

Something strange/good happened when I was doing this test. When I grounded the J209-9, I saw a "row short" on the row that hasn't been working. I went back in and tried to jump from J209-9 to all the pins for J207. They all work!

I don't understand what fixed this. Curious if this issue will come back to haunt me and if I still should buy a spare MPU board for when this issue comes back?

#14 8 years ago

AAA

pintechev

Inactive member

11y 91,300 4,437

I would send the board out for repair. There some sketchy soldering and what looks like some
corrosion.

#15 8 years ago

ZAZ

zaza

Pinside+ Frequent

OP
Quoted from Pmaino:
I don't understand what fixed this.

Quoted from zaza:
maybe bad connection in socket U13

#16 8 years ago

ZAZ

zaza

Pinside+ Frequent

Quoted from pintechev:
I would send the board out for repair.

I think a professional tech wouldn't take the risk to repair this one. A lot of thin traces are oxidized and there is still alkali on board.

#17 8 years ago

PMM

Pmaino

Pinside+ Frequent

Just ordered a new board. Figured this would be a reoccurring issue if I kept this board.

Zaza - thank you for the help. I have learned a ton from all your advice.

#18 8 years ago

ZAZ

zaza

Pinside+ Frequent

Glad I could help.
To bad the board has serious wear. It can be saved but it will take time

#19 8 years ago

PMM

Pmaino

Pinside+ Frequent