**Reel Slots** Gaming Machines => IGT S and S-plus Reel Games => Topic started by: Bob L on January 12, 2024, 01:15:30 PM
Title: S+ reels 'jumpy' on startup
Post by: Bob L on January 12, 2024, 01:15:30 PM
Hi, I've had an s+ double wild cherry slot for a long time and a month ago it wouldn't power up correctly. I fixed the power connector with trifurcon connectors, and now when I start the machine, the lights come on, the bill acceptor self checks, and then all three reels do a 'jumpy' spin (moving mostly forward, but jumping backward randomly). The reels continue this jumpy spin as long as it's powered on. I'm wondering if it has something to do with the stepper drivers. I've resoldered some of the power connections to make sure they're ok, and I checked the resistances on the reel resistors and they look ok (465-481 ohms). I did notice some 'browning' on the board near the three active reel resistors, and near one of the larger diodes (which I also resoldered just to be safe) I don't have a field service manual, and would like to get one but I haven't seen anything for my 'REV C' board. I've checked the fuses and they seem to be ok, and I'd like to check the voltages for the power, but I'm not totally sure how (I've read different things). I have a scope and other diagnostic equipment, but I'm unsure how to proceed. Any ideas would be greatly appreciated.
Title: Re: S+ reels 'jumpy' on startup
Post by: Stayouttadabunker on January 12, 2024, 02:09:23 PM
Be honest with yourself, did you at any point, take out or push in the MPU, while the power was on? Power surges cause flaky machine behavior, because IC components on the MPU can get zapped. Winter static electricity arcing across fingertps to IC components do damage as well.
I've seen "jumpy" reels, but not so bad where they've spun backwards. Only certain SP chips running with "Deluxe" Type games can make a reel spin backwards. Think of the SP chip as your "Windows 10" operating system, but to make a reel turn backwards , it needs to run with certain SS game chips. I can only think of the Haywire games doing exhibiting that behavior - during a bonus. Double Wild Cherry doesn't do this.
Follow this drawing below I made years ago to check the voltages going into the motherboard power Molex. Check by sticking your red multimeter probe (Set to vdc) into the top of the white Molex power housing, of course, with the machine's power switch ON. Your black multimeter probe just touching cabinet metal ground.
Click on photo below to enlarge if needed...>>>
Title: Re: S+ reels 'jumpy' on startup
Post by: Bob L on January 12, 2024, 02:44:09 PM
I've never unplugged the motherboard powered on. If you think the motherboard is the culprit, I could try to buy a matching one to replace. There's always a chance I inadvertently touched something, but I'm generally fairly careful. I did check all pins on the motherboard connectors and none were bent.
I checked the voltages - I don't get readings DC, but for AC pins come in at 0V, 0V, 7.8V, 8.9V, 12.6V, 12.6V. It's interesting that the two middle legs are a bit different.
The reels generally move forward, but occasionally will stutter backward for a step. It's not the fast spin I used to get on start up, it's a slow forward stepping with an occasional backward step.
I tried to post a video showing the behavior, but it didn't like a .mov file....
Title: Re: S+ reels 'jumpy' on startup
Post by: shortrackskater on January 12, 2024, 03:40:13 PM
To post videos, just put them on Youtube and post the link. :yes: Stayouttadabunker is talking about the MPU (or CPU) board, and not the motherboard. :propeller:
Title: Re: S+ reels 'jumpy' on startup
Post by: Jim on January 12, 2024, 04:14:25 PM
no. its correct, one voltage is 7vac, the other is 8vac, so they are good. sounds like you have ripple on the dc voltages on the cpu board. tough to get to see those voltages, only way would be to extent the test points via a wire. when the reels are locked in position, is it real easy to move them using one finger, if so then I an pretty sure you have some bad filter caps on the board, usually the large black caps.
Hope this helps
Jim
Title: Re: S+ reels 'jumpy' on startup
Post by: Bob L on January 12, 2024, 04:59:19 PM
Sorry, I meant to say I have never unplugged the MPU/CPU when powered on - I've never unplugged anything in the machine while it was powered up. Also, I meant to say that none of the pins on the CPU/MPU were bent.
I tried uploading the video of the reels to youtube, here's a link (first time doing this, so let me know if it doesn't work).
Thanks, Bob
Title: Re: S+ reels 'jumpy' on startup
Post by: Bob L on January 12, 2024, 05:18:03 PM
Jim, when I power the machine on, the reels 'snap to attention' pretty quickly and become firm. None of the reels is easy to move (like they are when powered off). I do have a storage oscilloscope up here, so I could look for ripple if I know the points to probe.
FYI, I'm including a pic of the MPU board I have....
Sorry the pic is lower resolution, but when I look at the higher resolution picture, one of the 1N 5401 diodes looks a little different, and I think it's the same one that the solder looked a bit different on (I resoldered all of them). I'm wondering if that diode has a problem. I don't have a schematic of the CPU board so I'm not sure what it's for....
Bob
Title: Re: S+ reels 'jumpy' on startup
Post by: Stayouttadabunker on January 12, 2024, 05:27:27 PM
Oh wow! Great video Bob! I have NEVER seen reels start up like that. They are all screwed up. Are you sure there's no bent pins touching each other? I'm going to bet the reel prom got corrupted or something zapped the reel drivers on the MPU. Is the reel prom in the socket in the right direction?
The reel drivers are the four chips with heat sinks that look like butterflies (Just right of the transformer) You'll see the empty socket for a fifth driver. They were for some rare five reel S+ machines a long time ago.
Title: Re: S+ reels 'jumpy' on startup
Post by: Bob L on January 12, 2024, 06:10:39 PM
I looked at the pins (both sets on the edge of the MPU board) with a magnifying glass and they all looked very straight to me. I haven't removed any chips since it was working perfectly (for years), so the chips should all be plugged in correctly.
I do see one interesting thing when I zoom in on the MPU photo - it looks like there could be some slight discoloration of the board near the butterflies of one of the chips. It also looks like one of the 'butterflies' is near (but not touching) another solder point on the board.
I will post a zoomed photo in a bit (Waiting for photo software to update....)
Title: Re: S+ reels 'jumpy' on startup
Post by: twinfire on January 12, 2024, 06:35:05 PM
Wow, looking at your video that thing is possessed!
After Jim’s comment about the Caps I looked at your board picture. Although the pics aren’t all that clear, two of the Caps kind of look questionable? Are the tops of the ones indicated by the yellow arrows raised at all? They should be completely flat on top.
Title: Re: S+ reels 'jumpy' on startup
Post by: Bob L on January 12, 2024, 06:39:46 PM
I'm attaching a zoomed in pic of the reel chips with the discoloration.
Is there a schematic for the REV C board version? I'd like to see if the interesting diode has some connection as well before I order a replacement.
Is it possible to get replacement reel chips alone, and is there any info on how to test the reel chips? If I had some schematics, I might be able to probe at the reel plug to see how things look. I could debug some of this stuff if I could get some documentation, but I haven't been 'reel' successful at finding any.
Bob
Title: Re: S+ reels 'jumpy' on startup
Post by: Bob L on January 12, 2024, 06:56:04 PM
Hey Twinfire, the caps seem pretty flat on top when I place a straight edge across them. Is the CR2 diode in the reel circuit? I think that one might be questionable.
Title: Re: S+ reels 'jumpy' on startup
Post by: Tilt on January 12, 2024, 07:01:26 PM
You're a contributing member, you can find some schematics here:
What's your zip code? Maybe I could run your MPU & reel chip on my test machine if you're not too far away?
I think he's a little far from you Mark. :propeller:
Title: Re: S+ reels 'jumpy' on startup
Post by: Bob L on January 16, 2024, 09:17:53 AM
I've been doing some homework on the power supply and reel circuits. It's challenging because I can't access the board while its powered up.
I did probe L1 and L2 of the middle reel with the scope (at the reel connector), and the square waves aren't great, but I think that might be expected because it looks like the 1042 chips are being driven in half step mode, and the outputs become high impedance at times in that mode. I've attached a picture that shows the waveforms, and it looks like they're running at 10.8 and 11.0V peak to peak, which looks like it's within the required range for the motors to be driven (i.e. the 11.5V +- 1.5V ). I didn't check out L3 and L4, but I will check them later.
I'm wondering if the problem is somewhere else, i.e. maybe with Vb, but I haven't been able to probe it (I did see that the solder points at CR2 looked a bit sketchy, but it looks like the diode tests ok). I also noticed that R97 looks a bit 'crispy', but surprisingly the resistance tests ok. I may try to solder on some test points (I can't find any test clips that are small enough). Does anyone have any recommendations on better way to access the voltages short of having a test machine (I don't think Mark will meet me in the middle to use his test machine :-)
Has anyone ever tried partially powering the CPU board to very the function of portions of the power supply at a time? I'm not at the location of the machine for a bit, but I do have the mpu board with me. I'm looking for cheap ways to be able to diagnose things outside of the machine...
One last question - I'm a bit perplexed at how the power supply gives the 11.5V at Vs given the higher incoming voltage (24V AC). Is the 5810 doing some kind of 'poor man's PWM' to keep the voltage lower?
Title: Re: S+ reels 'jumpy' on startup
Post by: Badbaud on January 16, 2024, 09:37:41 AM
The TIP125 power transistor starts the reel power with close to 24 volts. After the reels start spinning at 24 volts there is a 2N3904 transistor that powers the base of the TIP125 and drops the reel motor voltage (via theTIP125) to around 15 Volts to maintain the spinning. The 24 Volts give the reel motors a boost to get them going, then that voltage is dropped down and maintains the spinning.
Title: Re: S+ reels 'jumpy' on startup
Post by: Stayouttadabunker on January 16, 2024, 09:42:01 AM
...Is there a schematic for the REV C board version? Is it possible to get replacement reel chips alone...
Bob, Have you looked in the NLG File System? There are MPU board schematic diagrams in there in the IGT Games, subcategory area.
I've tried changing the butterfly reel drivers...I've had some luck, some didn't work. A lot of these IC components are obselete now but different places sell chips...you just have to search around. Personally, I get a lot of stuff straight from China, but I search first at places like Mouser.com, Digi-Key, FutureLec, oh there's so many places. China takes long so I look in the States first. Often I just order parts, forget about it, and when it comes in, it comes in. You would get China parts faster than me because you're on the west coast.
Title: Re: S+ reels 'jumpy' on startup
Post by: Jim on January 16, 2024, 10:05:59 AM
that's what I said earlier in my post, you would have to extend wires from certain test points in order to measure them.
you can test +vb at the digital display board, it is present across the large electrolytic cap.C-4--15microf at 25 vdc, the + vb should be around 10vdc.
Hope this helps
Jim
Title: Re: S+ reels 'jumpy' on startup
Post by: Bob L on January 16, 2024, 10:59:21 AM
I didn't realize the file system was there - thanks for pointing it out! I have some things that tilt gave me a link to above, but I'll dig around in the file system some more.
I think I might be able to verify the function of the other reel chips by just probing at the reel's themselves (although they're unplugged when I'm doing that).
Based on BadBaud's post, I'm concerned that the reel voltages aren't high enough. The power supply diagram says 11.5 +- 1.5 volts when high, and that's what I see (10.8V to 11V), but BadBaud says it should be more like ~24V and ~15V. A low voltage could explain the motors 'missing' a bit. Still, the fact that the reels spin forever makes me wonder about Vb. It also could explain the reels trying to spin forever on startup (if the reel sensors aren't working) Thanks for the info on where to probe Vb Jim. I'll also be able to look at that and for ripple on the 5V once I get the probes I ordered. I'm hoping it'll just be caps or diodes and not the reel drivers, but I did see some used stepper drivers for sale if needed...
Thanks for all the info!!! The more I learn, the more I want to get another machine :-)
Bob
Title: Re: S+ reels 'jumpy' on startup
Post by: twinfire on January 16, 2024, 05:46:38 PM
Hi, I've had an s+ double wild cherry slot for a long time and a month ago it wouldn't power up correctly. I fixed the power connector with trifurcon connectors, and now when I start the machine, the lights come on, the bill acceptor self checks, and then all three reels do a 'jumpy' spin (moving mostly forward, but jumping backward randomly). The reels continue this jumpy spin as long as it's powered on.
Just curious Bob, How was it acting prior to rewiring in a new replacement connector?
Title: Re: S+ reels 'jumpy' on startup
Post by: Stayouttadabunker on January 16, 2024, 11:40:16 PM
Here's how I repaired a S reel driver more than once...lol...>>>
Title: Re: S+ reels 'jumpy' on startup
Post by: Badbaud on January 17, 2024, 06:51:24 AM
Are you watching the 24V with a scope probe on the metal tab of the TIP125 transistor? Look for excessive AC voltage waveform. The main filter cap does go bad and need to be replaced to remove the excessive motor humping.
Title: Re: S+ reels 'jumpy' on startup
Post by: Bob L on January 17, 2024, 07:26:43 AM
Twinfire, I believe the reels weren't turning at all. The displays were blank. The first searches I did found the info about the burned plug and I saw the discoloration, so I fixed that. After that, the reels became jumpy. I didn't do a lot of analysis before fixing the plug because that looked like an obvious problem to fix.
Bunker, thanks for the video reference. I'm still holding out hope my reel drivers are ok because the couple outputs I looked at looked reasonable.
BadBaud, I should get new test leads today so I can check voltages while the board is plugged in. Unfortunately, I won't be able to test in in the machine for a bit, as it's in a different location. I'm hoping to get up there in a couple weeks. I thought about moving the machine temporarily, but it's pretty heavy :-) I've ordered some replacement diodes, and I may buy some extra caps just in case. I will test the 24V at the butterfly when I get to the machine.
By the way, one thing I noticed when looking at the board is that all 4 large caps are 6,800 uF's (two are 25 V, two are 16V). The schematic shows C23 as a 10,000 uF, but it's a 6,800 on mine. I'm not sure if it was replaced or it's just different on my rev of the board. I may just buy some replacement caps, and I'm wondering if I should get a 10,000 uF one for that.
Title: Re: S+ reels 'jumpy' on startup
Post by: Stayouttadabunker on January 17, 2024, 08:12:22 AM
Some of the older boards had those much larger caps I noticed they went to smaller ones, in the later revisions. I'd stay with the same size as the ones on the board presently.
Title: Re: S+ reels 'jumpy' on startup
Post by: Bob L on January 17, 2024, 03:51:29 PM
I decided to do a little more debugging on this at my brother's house (he's an EE) and I think we may have found the culprit.
We decided to partially energize the board just before the LM317 (i.e. from the output of CR3/4 to the isolated ground with ~11V DC) to see how the voltage regulator was doing. When we did this, we only got about 3V instead of the expected 5V, and we saw about 2.6 Amps were being drawn. The voltage regulator was getting really hot (as expected as it's a 1.5A regulator).
This seemed to imply that there was a short somewhere on the board so we tried to look for it by finding something 'hot' on the board. We couldn't find any thing hot initially except near the LM317. Thinking that maybe the LM317 was bad, we decided to desolder CR12 to disconnect the regulator from the downstream 5V, and it then stabilized right around 5V as expected. This implied that the LM317 was still working, although with no load, and that the short was coming from downstream somewhere. We decided to bypass the LM317 to be sure, and supplied 5V directly the 5V test point, and again we saw high current and the voltage was being dragged down to ~3V.
We looked for a hotspot on the board again, and the only area that was getting hot was right near the LM317 - it looked like the ESD protection at D3 was getting hot. We cut out one end of it, and then reapplied the 5V and everything looked good voltage wise on the isolated 5V circuit and the current was dramatically lower (I forget the exact reading).
This says D3 was definitely blown (I measure about 2 ohms across it both ways). It looks like the LM317 still works, and we're hoping nothing downstream was fried. I could in theory plug in the board like this to check, but I'm going to wait until I find a suitable replacement for D3 and put it in (Mouser has a 1N5908 that has specs close to the original/obsolete ICTE 5 on the board) . This may not fix everything that is wrong, but I'm actually optimistic it will. Undervoltage on the 5V could cause all kinds of strange things to happen.
My theory is that when the plug went out, maybe it caused an arc or something that blew D3. Hopefully D3 did what it was supposed to and protected everything else. I'll order the part, install it, and see what happens next (fingers crossed). It might take me a couple weeks to see if it works.
If anyone has recommendations for better matched replacement, let me know.
Just want to say thanks again to all of you for the continued help. I'll post again when I have the results :-)
Title: Re: S+ reels 'jumpy' on startup
Post by: Stayouttadabunker on January 17, 2024, 04:33:16 PM
I can't wait to see your results. I love the way you guys troubleshooted. :yes: You have to completely understand schematic diagrams to poke around like that.
BTW did you use a temperature gun to seek out heated IC components?
Title: Re: S+ reels 'jumpy' on startup
Post by: Bob L on January 17, 2024, 05:22:44 PM
My brother is a pretty smart guy and he’s done this a lot.
We didn’t have a thermal camera, so we used an infrared thermometer to find the area that was heating up. Then we checked with our finger. Pretty high-tech :-)