Tales from the Crypt
Data East, 1993Another game for me to help bring back to life. This time a TFTC. It's been on my short list for some time and a buddy of mine reached out randomly over the weekend and here we are 
What I know so far, non-booting, and at least 2 coils lock on. Leaking batteries were removed from the board but I didn't get a chance to see if it damaged anything.
I'll probably pull the board next to see if the leakage spread anywhere.
Any help along this journey would be appreciated!
Quoted from Crispy77:which coils are locking on?
From what I could tell, the kickback, launcher, and both slings. There could be more but I can only keep it on for so long. I will have to make a more comprehensive list when I look at it next.
Found a bit of corrosion on this microprocessor. When I removed it to try to clean it, it 'snapped' out of the socket. Noticed that a couple of the corroded legs were cracked out and when I went to clean it, one broke off clean. Hoping this is the culprit and that replacing it gets me back in business.
20230410_164924 (resized).jpg20230410_165831 (resized).jpg
Put in parts order for Cliffys, which probably won't arrive for some time, Titans, and a decent sized Pinball Life order.
Hoping to get the molded head from a fellow Pinsider and getting a proper door handle launcher. The previous owner went ham on this plain launch button.
20230410_202857 (resized).jpg
Well..installed a new 6802 last night and it still won't boot. Both 5V and PIA LEDS light up on the board and the kickback coil locks on, plus the VUK coil fires on startup (not sure if normal or not).
I know the kickback coil is a "special" coil and was going to try to sort that out, but I'm just thinking about sending the board in for repair since it seems like there are tools that I need that I don't have. I mean I could buy a logic probe, but it seems like an oscilloscope is probably the better tool.
Anyone with any experience that coild possibly walk me through repair?
I have the a new Chad code ROM coming in the mail. I'll probably wait to plug that in to try but doubt it would make a difference.
Quoted from FatPanda:Well..installed a new 6802 last night and it still won't boot.
Not all "new" 6802 processors are the same. Many of these are Hitachi processors in disguise. The Data East CPU board should have the issue that the Williams System 11 CPU board has when it comes to Hitachi processors used with an oscillator.
https://www.pinwiki.com/wiki/index.php/Williams_System_9_-_11#System_11_MPU_Jumpers
Quoted from FatPanda:I mean I could buy a logic probe, but it seems like an oscilloscope is probably the better tool.
You can use either a logic probe or an oscilloscope. The logic probe is the simpler tool and will allow you to diagnose most logic problems. It's a great way to answer "simple" questions as "are the address and data bus lines moving?". If you want to verify if you have a clock then you will need an oscilloscope.
Quoted from FatPanda:but I'm just thinking about sending the board in for repair since it seems like there are tools that I need that I don't have.
It's a lot of specialized knowledge to get these board working. Sometimes the problem is easy. Sometimes the problem is hard. There are a lot of things can be wrong to cause "no boot". Everything in the critical path must be correct to cause "valid boot". If the above bullet points are beyond your skillset then send the board out for repair.
Quoted from DumbAss:Not all "new" 6802 processors are the same. Many of these are Hitachi processors in disguise. The Data East CPU board should have the issue that the Williams System 11 CPU board has when it comes to Hitachi processors used with an oscillator.
https://www.pinwiki.com/wiki/index.php/Williams_System_9_-_11#System_11_MPU_JumpersYou can use either a logic probe or an oscilloscope. The logic probe is the simpler tool and will allow you to diagnose most logic problems. It's a great way to answer "simple" questions as "are the address and data bus lines moving?". If you want to verify if you have a clock then you will need an oscilloscope.
Start with swapping ICs installed in sockets with known good. A "new" IC does not mean "known good".
Verify address and data bus line connections. You can do this statically (no power applied by "buzzing" continuity between connection points as specified on the schematic). Concentrate on areas with obvious alkaline damage or previous repair work.
Use the Leon. If you cannot get the Leon working there is no way game code will work.It's a lot of specialized knowledge to get these board working. Sometimes the problem is easy. Sometimes the problem is hard. There are a lot of things can be wrong to cause "no boot". Everything in the critical path must be correct to cause "valid boot". If the above bullet points are beyond your skillset then send the board out for repair.
Thank you for your insight. It's a bit to fully digest so I'm going to read and re-read your post until I can fully understand.
In regards to the 6802, I bought the one from Pinball Life
https://www.pinballlife.com/mc6802p-40-pin-mpu-chip.html
How do I know if its a Hitachi chip? I didn't see any Hitachi markings on it.
I have other Bally SS games, that are not set up. I presume they have 6802s that I could swap from them?
There was not a lot of corrosion damage on the board. None of the traces were hit, it only seems to have fallen on the 40-pin socket and chip. I cleaned it with toilet bowl cleaner with a toothbrush and rinsed generously with 91% isopropyl and allowed to dry for a day. It looks very clean.
Thanks again for your help!
Quoted from FatPanda:Thank you for your insight. It's a bit to fully digest so I'm going to read and re-read your post until I can fully understand.
In regards to the 6802, I bought the one from Pinball Life
https://www.pinballlife.com/mc6802p-40-pin-mpu-chip.html
How do I know if its a Hitachi chip? I didn't see any Hitachi markings on it.
I have other Bally SS games, that are not set up. I presume they have 6802s that I could swap from them?
There was not a lot of corrosion damage on the board. None of the traces were hit, it only seems to have fallen on the 40-pin socket and chip. I cleaned it with toilet bowl cleaner with a toothbrush and rinsed generously with 91% isopropyl and allowed to dry for a day. It looks very clean.
Thanks again for your help!
The Hitachi brand chip has a 'HD' prefix (e.g. HDxx6802xx)
Quoted from FatPanda:How do I know if its a Hitachi chip? I didn't see any Hitachi markings on it.
https://pinside.com/pinball/forum/topic/suspected-rebranded-6808-validate-my-theory
Power supply Voltage:
+5V TP sees 4.97
+12V TP sees 10.94
-12V TP sees -15.27
MPU +5V sees 4.92
Do these numbers look out of whack?
Sent the MPU off to get repaired yesterday. Hopefully that sorts the locked coils, no boot, and anything else that might have been wrong.
Until then, topside teardown and shop job.
Well, got the MPU back and no go. Still the same issues. The tech reported that the MPU worked and booted on his test rig, so going to check the PPB next and then the PSU. Anyone have any thoughts on what I can do to narrow down the problem?
Recapped the power supply and the game boots! The tombstone VUK locks on and the display is garbled but it's progress!
Hoping the display fix is easy. Going to see what transistor is associated with the locked on VUK and hoping that's an easy fix too.
Quoted from CrisCrow:that's good to hear! I was just thinking about this thread as I'm going to start getting into my TFTC soon now that I've freed up a bit of space.
Is yours having trouble too?
yeah I have the same thing going on and had tried swapping boards but that didn't help I ended up with a bunch of other projects and that game is my personal game so I left it for awhile while I tackled more important things. but now I'm going to try and start getting into it
Quoted from CrisCrow:yeah I have the same thing going on and had tried swapping boards but that didn't help I ended up with a bunch of other projects and that game is my personal game so I left it for awhile while I tackled more important things. but now I'm going to try and start getting into it
Well, I would try recapping the the power supply first! 
If you reference my test point numbers above, it'll give you an idea of was happening with mine.
Things to look into. Locked laserkick, locked tombstone VUK, upper flipper not working, garbled DMD.
I tracked down the coils to Q3 and Q4 I believe, but will likely just replace all 4 since I'll have extras.
Will check the EOS switch for the upper flipper.
For the DMD, I've seen to check/replace the ribbon cable. I'm going to order a new one(s) and see if that works. 26 pin and 14 pin ribbon cables.
Replaced all the affected TIP 36C transistors and it addressed the locking coils. also used a spare DMD I had and it works but flickers. Getting a colorDMD this week that will hopefully resolve the problem. I did replace the ribbon cables but it was still the same.
Checking the EOS got my upper flipper working again.
It's finally up and playing again after a month of work! Just needs a few odds and ends to get it perfect but it's a choppin' good time!
20230514_114435 (resized).jpg20230514_120834 (resized).jpgWanna join the discussion? Please sign in to reply to this topic.
Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!
This page was printed from https://pinside.com/pinball/forum/topic/tales-from-the-crypt-troubleshooting-thread and we tried optimising it for printing. Some page elements may have been deliberately hidden.
Scan the QR code on the left to jump to the URL this document was printed from.
Windsor, ON
Wiener Neustadt
Lake Elsinore, CA