OK, since everyone was so helpful with my Getaway and several people expressed interest in helping me fix my T2, I figured I'd create this thread now before my replacement fuses arrive.

First, some background on my machine. Feel free to skip this section if you just want to hear about the current problems, but there is some potentially relevant info here about prior issues that led up to the major one I have now.

Background:

This T2 is in fairly rough shape. It was in a building that caught fire, and while the machine was untouched, there is a lot of soot on parts of it. Honestly, the machine isn't worth fixing from a financial point of view (the cabinet is rough, the playfield is cracked by the shooter lane), but its the first game I ever played more than a few times so it has some sentimental value. I was also able to acquire it for next to nothing, so other than some money in parts I haven't put too much into it yet.

Despite the overall condition, the game actually played fairly well with no major issues up until a few months ago. The first problem I had was that the game suddenly started failing to boot. It just emitted a periodic clicking noise from the speaker, and the D19 LED on the MPU board never went out. I discovered that if I unplugged the top ribbon cable from the DMD control board, the game would boot up fine (but obviously, the DMD would be dark). I tried replacing the ribbon cables, then replaced the DMD control board, and finally swapped out the entire MPU board.

Swapping the MPU board 'fixed' the problem, and after that the game ran fine again. However, a few weeks later I removed the MPU board and tried swapping the game ROM for a different ROM set, and when I returned the MPU board to the game and hooked everything back up again the boot problem returned . The issue returned in the exact same way: the game wouldn't boot unless the upper left ribbon was removed from the DMD control board.

After the problem returned, I first re-seated the ribbon cables, then tried replacing them with a new set of cables. However, the problem persisted. I then checked the voltages on the power driver board, and I found that the +5v was a bit low (4.875). I decided to try to swap in a new power driver board to see if the problem went away if I cleaned up the power issues. I then swapped in a rottendog power driver board from my getaway (see previous thread for that story). I tested the voltages, and they were all spot on with the new board. However, this did not correct the boot issue, which remained and occurred in exactly the same manner.

If I allowed the game to boot by unplugging the upper left ribbon on the DMD board, the game would immediately reset and start clicking if I plugged the ribbon in while the game was powered on. It would then boot up again properly if I unplugged the ribbon cable again. So, something about plugging the ribbon cable into the DMD board brings the machine down. Also, I tried unplugging the sound board and just connecting the MPU and DMD boards, but the same problem happened.

Current issue:

OK, on to the main event. In an attempt to figure out the issue described above, I began fiddling with the ribbon cables. I removed them, examined them again, and then put them back into the machine. This time, I left the DMD control board disconnected entirely (both the left side ribbons were left unplugged). This is when the 'incident' occurred...

When I turned the power back on, I immediately heard a loud pop from the speakers (I think). I immediately turned the machine back off again (my finger never came off the switch, this happened instantly). I unplugged the machine right away and took a look to see what happened. I discovered the following:

-The F105 fuse on the power driver board blew
-The main 8A line filter fuse blew

I did not observe any further damage, but I also don't know what I'm looking for, so all I can say for sure is that none of the other fuses blew.

Current state of the machine:

Right now, I have the power driver board out of the machine. I haven't replaced the main line filter fuse yet (replacement fuse set coming soon). I have no idea if the machine was damaged beyond the two fuses that I mentioned that blew. Right now my question is, how should I proceed from here? Obviously the fuses that blew need to be replaced, but beyond that, is there anything I should do before I attempt to power this thing back up again?

Also, do you think it is wise to attempt to use the power driver board that was in the machine when the fuses blew, or is it likely that it was damaged in a way that could cause further problems in the machine? I will post some pictures of the original power driver board and the rotten dog that was in the machine when the incident occurred.

PinballManiac40 mentioned in my getaway thread that this sort of thing can happen if the ribbon cables are plugged in shifted over by a row. This makes total sense, since I was fiddling with them just prior to this. What sort of additional damage to the machine is something like this likely to cause?

Thanks in advance!

P.S. On the advice of Haggy38, I have ordered a head lamp so that I won't have any further issues seeing the cabling in the backbox. I will be much more careful with the ribbon cables in the future.

Here are a few photos so you can see the two power driver boards I have available. The first is the rottendog board that was in the machine during the incident. All the fuses in here test OK, other than F105 which blew. I'm not sure if the board is any good now, since I don't know if there was damage done to it when the fuse blew.

The second is the original T2 board. All the fuses test OK here, and the game did work with this board. However, as you can see it's very dirty, and the components are all original. The voltages this thing puts out are a bit out of spec, to the point where I'm not sure I want to use this again unless I have to.

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Hi,

I agree the problem was never fixed. What you say makes sense. I have however tried 2 different ribbon cable sets, 2 different MPU boards, and 2 different DMD controller boards. Therefore, I believe the problem isn't a loose connector on any of these boards (unless you suspect otherwise). Does it make sense that a bad connection elsewhere in the machine could cause this issue?

Regardless, I will double check every connector prior to attempting to power this back on.

OK, so I have swapped all of the following components:

-Replaced DMD control board with new rottendog dmd control board
-Replaced ribbon cables
-Replaced MPU board with working MPU board from getaway (purchased new MPU board for getaway)
-Replaced power driver board with rottendog power driver board

I did these replacements one at a time, leaving the replacement component in the machine afterward (for example, after swapping DMD boards, I didn't put the old one back before replacing ribbons). The same boot issue happened after each replacement (exactly identical symptoms).

In my mind, this rules out each of these components, but perhaps I'm overlooking something?

I also forgot to mention one little detail, if it matters (I'll update the original post to include this):

If I allowed the game to boot by unplugging the upper left ribbon on the DMD board, the game would immediately reset and start clicking if I plugged the ribbon in while the game was powered on. It would then boot up again properly if I unplugged the ribbon cable again. So, something about plugging the ribbon cable into the DMD board brings the machine down. Also, I tried unplugging the sound board and just connecting the MPU and DMD boards, but the same problem happened.

Understood, I won't try it again.

I am currently using ribbon cable sets from marco. I'll try ordering a set from the site you linked, in case that helps.

Right now the power driver board is out of the machine. Once I decide which of the two I have I want to try using and replace the fuses, I'll hook everything back up and post some photos before attempting to power the machine up.

Do you have any advice regarding the power driver boards?

Thanks.

What you are saying about a bad connection makes total sense to me.

The reason I'm a little skeptical that it is a loose connector one one of the boards is because I have swapped out every board in the backbox (other than sound, which I did try bypassing), and the problem persisted with the replacement boards. It seems unlikely that I would see the same problem after swapping every board if the problem was a loose connector on one of the boards, but it's always possible there is a similar issue the original and replacement boards I suppose.

That being said, and I will definitely do the test you suggest on every connector on every board in the backbox later tonight. I'll let you know if I discover any that have any play on them at all. I won't be able to test anything with the machine powered on for at least a few days until my new fuses arrive though.

Thanks for the tips!

No problem, I should have been more clear on this from the start. I've tinkered with this machine so much I forgot to mention several things initially.

Regardless, what you say makes sense. I will double check the connectors anyway. At this point, it feels like I've ruled out so many things that I must have incorrectly ruled something out, so it will be good to backtrack and re-eliminate all the boards

I got sidetracked for a few days with other projects, now it's time to get back to the T2.

My fuses arrived, and I replaced the burnt ones. I also replaced the other fuses on the old power driver board since they looked corroded, and I wanted to make sure the ratings were all correct.

Right now, here is my plan for this machine. Please let me know if you see any problems with this:

-Replace blown fuses, including line fuse (already done)
-Reinstall original power driver board (not the one that was in the machine when the fuses blew)
-Disconnect sound board, dmd, and dmd control board entirely (I want to try booting with as little connected as possible)
-Attempt to power on again

Does this sound reasonable/safe? Am I correct in assuming that its safe to power on the machine with the sound, dmd, and dmd board disconnected from everything? I want to reduce the number of things connected and make sure the machine isn't blowing fuses before I attempt to reconnect anything I don't have to.

Thanks.