Magical Drop II - Sound Glitches - Need Advice

I got my hands on a copy of MDII with some sound glitch problems (all over the place, and fairly loud too). It's legit, tried pink erasering the contacts really quick, but no change there. So I've popped the boards out and I see some flecks of... something on them. Figure I'll give the whole board a good clean down and I notice that they're both tacky to the touch. Qtip and alcohol gets the sticky off, but it's Rough goin. I have no idea what's on here, but it's pretty gnarly. You can't see it, but it's almost like there's a film over the /entire/ board (once you clean a spot with the q-tip you can see a clear outline in the coating.

Any ideas what the heck this could be and perhaps a faster way to get it all off other than q-tip swirlies?

For a point of reference on /how/ tacky I'm talking, if I press my fingertips into it on the back of the board, I can pick the board up by it. Eww.

Remove all (if any) socketed ICs and run the boards through the dishwasher. No heated dry, and no cleaner, just straight water.

68k said:

Remove all (if any) socketed ICs and run the boards through the dishwasher. No heated dry, and no cleaner, just straight water.

Click to expand...

. . . seriously? You can wash a PCB in hot water?

I would not use hot water, but you can wash a PCB in a dishwasher if all socketed ICs have been removed, and all batteries have been removed.

You'll want to dry the boards as much as you can after washing, and wait at least 24 hours before testing them.

Well, no socketed ICs, just the standard soldered on chips youd find in a reguar ol MVS cart.

Well, turns out we had a fairly large bottle of alcohol here at work, and a few bins, so I was able to to an alcohol bath on the boards. Cleaned up pretty damn nicely. Compressed air dried 'em off, pink erasered the contacts one more time. Still sound glitchy. Sounds more like it affect sound effects than it does music. The solder joints look okay to me, but that doesn't necessarily mean anything. I did notice that two of the ICs appear to have been pushed a bit.

What I mean is that instead of having the same clearance underneath that the others on the board to, with nice straight legs, then appear, instead of have been pressed down, and all the legs are slightly bent. Is it possible that this is the cause of the sound errors?

I'm going to assume that the only way to fix that would be to de-solder the chips, /carefully/ straighten the legs back out, and resolder them?

Any advice on doing that? I don't think I've ever seated anything much more complicated than ye olde 555 timer ICs, and even that's been /years/. Thanks!

Have you tried cleaning your cart slot -- if as much nasty stuff was on the cart as you were talking about then it was probably all over the contacts and probably in the mobo cart slot now.

Have you tried inserting the cart and pulling it back out slightly?

Have you tried slightly moving the cart back and forth while the glitches are happening?

And last, have you tried clearing out the back up ram (that can cause all kinds of wonky problems)?


As cheap/available as MD2 MVS carts are, I would personally replace the cart if none of the above works. Of course that's just me and I don't have much free time available.

And yes, you can wash PCBs without batteries. Just no detergent and do not use the hot water option or heat drying. I have found that the hot water option on my diswasher leaves mad white deposits all over the PCB and it's a pain to get it off. Make sure PCB is 100% dry before power is applied (I know...goes without saying...)

Ah, detailed answers. See? This is why I love this forum.

Yeah. I cleaned out the slots on the mobo. First thing I did when I saw the crud on the cart. Only other game I have that has any sound glitches is a bootie SSVS, which I knew about before I picked it up.

I'll try shimmying the cart around to see if that helps any. As silly as it sounds, I also know how persnickety the system/carts can be (I've got an MSlug that I have to prop apart from the other cart in my 2-slot or it just wont play).

I'll also try the backup ram thing. Couldn't hurt.

And yeah, I know they're cheap. I actually just sold another copy of it, hehe. Picked this one up on the cheap, with the intention of probably turning around and selling it too. I've always prefered Mag Drop III over II.

Worst case scenario Ive got a project for a SLOOOOW day at work or a space cart shell (repro label anyway) and some boards to sell off for parts.

This is now a purely academic pursuit (Learning is fun!).

Cleared the backup ram, seemed to clear really quick (went into test mode, hardware test, 1P button to clear screen, hit A B C together, let go, went straight to Time screen). Not sure if that means anything or not.

Any rate, no change. Tried doin the cart shimmy. Pulling it back a little, moving while sound glitches, etc. It's definitely something to do with the sound effects, not the music. At one point the glitch didn't go away inasmuch as just get quieter, while the music was fine. At one point, all sound stopped altogether (game still played fine though).

Hit test button, then exit, screen came up "Z80 Error". Power cycle, and back to glitchy we go.


This is the first board, the bent chip is the left-most chip.


This is the second board. The bent chip is the upper-right-most chip.

Thoughts?

The V1 chip is the sound rom, if that's the bent one make sure all the solder joints are good. I would just reflow the solder to all the joints on that chip.

Xian, you rock!

I popped on a loop to look at the connections on V1, and sure enough a few (where it's bend the worst) looked dodgy. Reflowed them all (looked up on youtube, it really is SIMPLE to do). I also touched up any other connections that looked less than great.

Works great now! Thanks!

Thanks also to anyone else who dropped advice in here.

I wonder if bad joints all that's wrong with the super strange SSVS bootie I've got. . .

Congrats on getting the cart to work!

Missed the part about the bent legs...guess I need to laern how to read.

Your advice was still good, and frankly, doesn't hurt to do before breaking out the soldering iron.

Cool, but you should get MD3 instead. It's better.

Yeah, hehe, I've got a copy of MDIII.

I gotta admit, I haven't played 2 yet but love 3. A few games in the collection I won't get rid of and that's one of them.

Thought about getting 2 just to check it out but with all my other arcade projects going on I always find something else to spend 20 or 30 on instead.