Star Trek: The Next Generation
Williams, 1993When I got it it had a chip that had a sticker on it that said 'Whitewater', so I ordered a STTNG chip and replaced the whitewater with it.
It also didn't have a display, but I popped an old one in there.
It powers on, but no lights come on and the DMD is a jumble:
Powered on - The chip I replaced is there - No leds lit on this board?
There are like a million bits of information you will need to help troubleshoot.
I would start with pinwiki. Try a few things. Get back to us.
Quoted from coz6:Every time I have seen a screen like that I had a ribbon cable off a location.
Same; check your ribbon cables against photos of a working game. I just had this happen on the AFM that I am finishing a restore on.
Yup always make sure your ribbon cables all have the red line going to pin 1 and also that they are properly seated. also make sure you pull all your fuses and test them with a meter . I've tested fuses before without pulling them and they tested good but when I pulled them they were bad . Just a thought
I pulled all ribbon cable connectors, made sure the red line is at number 1, and replaced them back - no change.
None of the CPU Board's 3 LEDs are lighting, I'll look for a test point on the CPU board (is there one, or should I check at the cable coming onto the board?)
Ok, I checked all the fuses on all the backbox boards - there was a 3A 250V fuse blown on the power board, it is in F115 but I have yet to track down more info on that fuse.
I checked the CPU board's incoming voltage on the incoming power cable, and it reads 0.55. (I used 20 DCV setting on my meter, I hope that's right)
What's interesting is that before I replaced that fuse, I also checked the incoming 12V power to the CPU board and it read ~2V, after I replaced the fuse it read ~12V.
It looks like the GI to Backbox and GI to playfeild cables from the power board are not attached, I believe I missed them because they have weird connectors on them, and it looks like at one point there were cables directly soldered to the board connectors for the playfeild GI. Heres a picture of the previously soldered board connector and the 'weird' connecter that the wires which are supposed to connect to it have:
NOT stock connector... Need a new Connector I guess
Aside from those connectors, it looks like my 5V is having issues. I checked Test Point 2 on my power board and it read 0.28.
Beyond this, I'm unsure where to go... I guess my board needs repair. Questions:
-Are there any further diagnostics I can do or at this point should I start working on my power board?
-What should I look at replacing on my Power Board?
-Would the 5V issue be possibly causing the scrambled DMD?
A missing 5 volts will guarantee a non booting CPU / game. Start their - the pinwiki manual will walk you through on how fix this. For me I had to replace the following item shown I did not have a way to test it but $2 part and the most common to fail. Great Plains sells them FYI
Looks like a voltage regulator.
http://www.pinwiki.com/wiki/index.php?title=Sega/Stern_White_Star_Repair#Low_.2B5VDC_and_Game_Resets
Well, I always hated soldering... I never have any luck doing it.
I just reheated some connectors and reflowed some solder on a few points and now I get nothing at all from my 5V... I guess I'll order one of those LM323k voltage regulators, but I'm not holding my breath on my ability to fix the board myself.
I'm guessing I'll need a new one or send mine in for repair.
It did look like someone with even worse skills than mine had tried to repair the board previously, so that can't be helping things along either.
Don't just blindly replace parts. You're just throwing money away.
Step 1. Game unplugged. Pull every fuse, verify it is good with a meter - not just visually! Check the value against the manual. Replace any blown fuses, or fuses of the wrong value, with good fuses of the correct value.
Step 2. Unplug everything from the driver board but J101, J102 and J112. Check the test points on the driver board. All of them. Post the readings here.
Step 3 - someone will help! If you need your boards repaired, I can do it.
Thanks John... I was discouraged last night, just had a bad day overall - I appreciate your post, it made me lift my chin.
I tested all the fuses with a multimeter, they're all good now.
I did as you suggested and unplugged all from the driver board, except J101, J102 and J112. And tested all the Test Points I could find:
TP1 - 15.19
TP2 - 0.00
TP3 - 12.09
TP4 - 0.00
TP6 - 72.00
TP7 - 21.00
TP8 - 17.70
It really looks like my 5v is the issue, does that sound right?
You'll get there! Have no fear.
Looking at the numbers you're getting, everything is good but TP2. Your +5 is totally gone. Not too low, gone.
Did F113 blow again while you were testing it? Are you sure? Test it again 
If it's blown, BR2 may be shorted.
There are a number of likely culprits, but many of them would likely give you a low +5 vs no +5.
Meter on AC Volts. 1 lead on J101-1, the other lead on J101-2. You should get ~9 VAC. If you've got that, or pretty close to that, your transformer is good.
Most likely culprit, IMO, is BR2. Test BR2 using your DMM on diode test.
Instructions:
http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Failed_Bridge_Rectifier
While your board is out, it's a good time to do a good visual check of BR2. I find a good flashlight helps me figure out a LOT of problems! Look around the 4 leads of BR2. Do any of the leads look like they've been butchered? It is pretty common on WPC driver boards at this point, so don't rule it out til you check it.
If the bridge is good, and you've got good voltage coming in, get your schematic out, and test the connections to/from BR2 and C5. These are often compromised when replacing these components.
I tested the fuse again to be sure, it's the right one and it's good.
The AC Volts test on J101-1/J101-2 cane out with 9.4, so that seems OK, right?
I tested BR2 following your posted link's instruction, I got around 550 for the neighboring points, but read a 1200 or so from the adjacent point, like so:
Try not be jealous of my amazing art skills.
I think that means the BR2 is bad... can you confirm?
I'm not sure what you mean by butchered... but does this qualify? It's not my doing, before you ask:
The back side of the LM323 is typical. They get hot. Nothing unexpected. Should not be causing an issue.
I think you did the bridge test incorrectly. You should have 2 different sets of values relating to the A/C leads. There should be no reading related to the - lead - meaning the 1200 reading is erroneous
Go back, and run the test again please.
Hopefully, a carefully placed jumper wire between the red circles will restore your +5.
That cpu has significant corrosion damage. Best bet is to replace it, or send it out to a pro for evaluation. Corrosion spreads and is labor intensive to neutralize / repair.
Beat you to it! I looked carfully and it seemed to be those points were supposed to be connected, so I added a jumper and voila, it lit my 5v LED! Now some solenoids fire when I start my game. Still a scrambled DMD though... likely an issue with the CPU board? I'm not sure.
Yea, I had a feeling about the CPU board. If I grab a rotten dog one, do I need the (with ASIC installed) version or will the (bare) version work?
http://www.bigdaddy-enterprises.com/ProductPages/RotDogBoards.html - about 3/5 the way down the page...
Personally, in this case, I'd go with the 'ASIC installed' version, and also get the 6809 as well.
Why?
Sometimes, project games get a bunch of bad boards dumped in them. I've had corroded CPUs come in for repair with bad ASICs, wrong processors, all sorts of things. They sometimes sit in a box under somebody's bench, and they rob parts off them to fix other games.
I'd suggest starting with something that you *know* is good. If you had another WPC-89 game that was 100% working, you might be able to get by with a bare board. Granted, you could test your ASIC in your WPC-S games, but it's possible to damage the ASIC if you're not super careful removing/installing it, and best case scenario, you'll end up with a spare this way.
Alright, finally received the board. I installed the STTNG chip onto the board and installed the board in the machine.
I also replaced a couple connectors on the power board, J120 and J121.
However, the game still won't boot. The GI and play field lighting now light up and stay solid, but there's still a scrambled DMD. If I press the test buttons inside the door I can randomly enter test mode where the play field lights flash and the cannons rotate.
Can you offer some ideas for my next things to check.
I went through the PinWiki and found the section on the 'Power-On LEDs and Sound Tones (Bongs)' and the LEDs on the new CPU board seem to be happy. The top LED turns off, the second one blinks and the third one stays solid.
I also only hear a single tone when I power on the game which I believe is a good sign, since the PinWiki states "After a successful boot, the game should make a single "bong" sound." - there are no additional bongs so I think this is good too.
When the game is powered up, the playfeild & GI lights turn on but stay solid. Usually in attract mode (in my other games) they turn on and off / flicker / etc. But they don't. Can someone confirm if they should flicker when you power on STTNG?
New CPU Board
Playfield lights now function, but stay solidly lit
DMD is still 'scrambled'
The LEDs all light and seem to be proper
Thanks Doc for checking that for me.
Yea, my inserts don't illuminate unless I get into the test mode by randomly mashing the buttons inside the door. Once I do though, they flicker like I would think they would in attract mode.
It's tough to troubleshoot with the DMD not functioning. I guess I'll check the DMD voltages when I get home from work today. Still trying to dig up what else I can look into...
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