Tech Help: Scared Stiff Spider Wheel (FIXED)

Problem:
Scared Stiff spider wheel not spinning.

Observations:
Opto checks OK
LED1 on D-12046 stepper motor board is ON
Motor shaft resistant to spin when powerd ON but will spin easily when powered OFF.
All connections/wires appear to be OK
All solder points/headers on board appear good
All fuses check and are OK
Update: Checked +12V coming into controller board and it is good
Update: Replaced Lm339 comparator. Did not resolve issue
Update: Unplugged J110 and grounded ylw/wht and grn/wht. Each condition yielded a motor response (twitch). Replace U3 next?

Options:
Coincidentally, Who Dunnit is next to Scared Stiff. Can easily swap stepper motors (to rule out problem with motor)
Update: Swapped out stepper motor. Did not resolve issue. Stepper motor acted the same (motor shaft resistant to spin when powerd ON but will spin easily when powered OFF)

Best Guess:
GUESSING the LM339 is bad. Again, just a guess.
Update: Replaced but did not resolve issue
Update: Potential issue with U3 chip. Next step is to replace the chip.

Helpful Links:
http://www.ufopinball.com/pub/D-12046.gif
https://pinside.com/pinball/forum/topic/scared-stiff-spider-wheel-problem

Anyone have ideas, please let me know. Also, go enjoy your 4th of July instead of scanning the Pinside threads.

Post last edited 7 years ago.

#2 7 years ago

QRK

Deez

Pinside+ Frequent

12y 139K 6,785 13

I've fixed a bunch of these. It's usually the LM339.

#3 7 years ago

SID

xfassa

Pinside+ Pro!

Actually found an LM339 in the drawer. Crossing my fingers....

#4 7 years ago

SID

xfassa

Pinside+ Pro!

Hmmmm.....replaced LM339......same issue. Ideas???

#5 7 years ago

ZAZ

zaza

Pinside+ Frequent

OP
Quoted from xfassa:
Ideas???

U3 (uln2803) on the powerdriverboard and the transistors on the steppermotorboard are next to check.

Little test:
-machine 'ON'
-unplug J110 from PDB and use a wire to 'ground' Yellow-White. Does the steppermotor make one step ?
- repeat with Green-White, does it make the motor move one step ?

If there is no response at all, the steppermotorboard is the one to check.
If there is response, it would likely be the driver U3 on the powerdriverboard.

Super exclusive ad from the Pinside Marketplace!

Machine - For Sale

Scared Stiff New ad! Featured

Used - shows wear but 100% working and clean - “Very nice scared stiff with powered coated metal and topper”

9 hours ago

Reno, NV

Jecco74

10,000 (Firm)

#6 7 years ago

SID

xfassa

Pinside+ Pro!

Quoted from zaza:
If there is no response at all, the steppermotorboard is the one to check.
If there is response, it would likely be the driver U3 on the powerdriverboard.

I got a response (spinner twitched) with both the ylw/wht and grn/wht. So....I need to replace U3? Thanks.

#7 7 years ago

ZAZ

zaza

Pinside+ Frequent

Not yet, to be sure you need to measure inputs and outputs on PDB-U3, or if you have another WPC95 powerdriverboard you could try if it works.
Also you need to know that all other outputs driven by U4 are working, that is flasher #25-28 and sol.#37+38. (sol. #39+40 are spiderwheel).

If the flashers #25-28 and sol#37+38 did work in testmenu, and the spider didn't twitch at all in the spider-wheel test T.16, it is very likely U3 on the PDB.

#8 7 years ago

SID

xfassa

Pinside+ Pro!

Quoted from zaza:
Not yet, to be sure you need to measure inputs and outputs on PDB-U3, or if you have another WPC95 powerdriverboard you could try if it works.
Also you need to know that all other outputs driven by U4 are working, that is flasher #25-28 and sol.#37+38. (sol. #39+40 are spiderwheel).
If the flashers #25-28 and sol#37+38 did work in testmenu, and the spider didn't twitch at all in the spider-wheel test T.16, it is very likely U3 on the PDB.

Flasher #25-28 do not work in test menu. Solenoid #37+38 do not show up in test menu. Replaced U3, same problem. Swapped in known good WPC95 board, same problem. Not sure where to look next.....

Ideas? Anyone?

#9 7 years ago

ZAZ

zaza

Pinside+ Frequent

If flashers #25-28 and all outputs of PDB-U3 don't work, the cause has to be found in the U4-enable.
Now that the driverboard has swapped, the CPU-board is the one to check.

Re-seat ribbon cable on CPU J211 and push ASIC U9 gentle in it's socket.

#10 7 years ago

SID

xfassa

Pinside+ Pro!

Quoted from zaza:
Re-seat ribbon cable on CPU J211 and push ASIC U9 gentle in it's socket.

Reseated ASIC and J211. Success!!!! THANK YOU.

I feel kind of dumb now for replacing chips unnecessarily. Oh well, they are socketed now to make future chip swaps easy.

#11 7 years ago

ZAZ

zaza

Pinside+ Frequent