TheShanMan's Defender restoration - New repro wiring harnesses!!!

[TheShanMan]

I finally have what will be a dedicated arcade game: Defender! Picked it up for $100, not working. It'll need some cosmetic attention, though it's not bad - artwork is relatively good for 28 yrs old, but the lower front panel, which is pressed wood, has water damage (thankfully the panels that have artwork are plywood!). I imagine that's easy enough to replace.

The big challenge for me is going to be getting it up and running, though thankfully we have some Williams experts like RetroACTIVE here (I'm counting on you guys! ). I haven't fired it up yet, but he said the screen comes on red, and no sound. I see one of the monitor boards is popped off - not sure if that happened during transport or if that may have been part of the problem. Also I see a part of the monitor is broken off of it's mounting point, but not sure if that's a significant issue.

I probably won't want to spend a lot of time working on this in the short term (I have enough stuff to do right now), but I would like to cover the basics and see if I can get it going without a lot of effort.

The guy actually thought the corroded high score batteries might be the problem!

Pictures to follow very soon.

[TheShanMan]

Here are the pics.

[TheShanMan]

And some more...

[SirPeale]

One of the monitor daughtercards isn't plugged in.  In one of those pictures it's to the left of the monitor.  Without it won't work.

[Level42]

All your board-set problems are (soon) solved:

http://forum.arcadecontrols.com/index.php?topic=83897.0

[SirPeale]

The guy actually thought the corroded high score batteries might be the problem!

They very well could be part of the issue!  The corrosion gets into the board and actually creeps along the traces.  Destroy enough traces, board stops working.

[Level42]

http://homearcade.org/BBBB/wmsbatt.html

[TheShanMan]

One of the monitor daughtercards isn't plugged in.  In one of those pictures it's to the left of the monitor.  Without it won't work.

Yeah, I mentioned that in my first post. It may have popped out during transport, or maybe it was like that before - dunno. On quick glance I couldn't tell which way it plugs in, and I don't want to plug it in the wrong way and fry something! I'll go out and have another look. Hopefully it can only plug in one way.

The guy actually thought the corroded high score batteries might be the problem!

They very well could be part of the issue!  The corrosion gets into the board and actually creeps along the traces.  Destroy enough traces, board stops working.

Ah. Good point. Though I know the guy wasn't thinking of that - he said he knows nothing about arcade games. I'll look closely at the area surrounding the batteries and see how it looks.

Thanks Level42 for the links. I ran across those last night when I was searching the boards here for anything relating to Defender restoration. The lithium battery idea sounds good. I haven't read that page yet, but if it's a simple/quick conversion then it's a no brainer. I don't want to go down the road of that multi-williams board at this point. I'd like to keep it as authentic as possible.

[TheShanMan]

I plugged in that monitor board (yeah, it only goes in one way). Fired up the machine. First I see a yellow hash pattern, and then after a while it goes red and then I start hearing a sound that alternates between 2 frequencies 2 or 3 times per second (kind of like a police siren, but much faster). Here are pictures showing each of the screen images, as well as a picture that focuses in on the battery area. It doesn't look to me like the corrosion is enough to make it stop working, but I'm no expert.

Oh, and after I giggled some wires, the 4 led's went red (they were off prior to that). I also checked the voltages at the PS - 5.00V, -4.96V, and 11.97V, so that seems fine. Although I hear a high pitched noise that seems quite a bit louder than I'd expect it to be, and I think it's coming from the PS.

Also, could an expert have a look at picture #4 (above) and tell me if that coil that's hanging is a problem as is? I can see where it's supposed to go, but it doesn't look to me like that would cause an electrical problem. And if you see picture #5, there's a red wire that goes off the bottom of the picture, which is just dangling there. I'm not sure where it goes exactly, but I'm guessing it goes on one of those terminals next to the yellow wire that's by itself. Can someone tell me where it goes?

I would really appreciate advice on how to proceed!

BTW, monitor pictures are a bit washed out, but in person it's quite yellow and quite red, trust me.

[TheShanMan]

Is there a defender manual available online?

[SirPeale]

The thing that's hanging down is the width coil.  As long as it's not totally broken or touching anything, it'll be fine.

Looks like you're getting rug pattern in that last picture.  That's a good thing. 

I'll bet you have at least one bad RAM.  You should switch it over to 4164 anyway.  More reliable.  I'll be offering a 4116 --> 4164 converter in the very near future.

Check the bottom of the cab, you might find some 4116 in there to see if it's running OK.  Stuff in bags = likely ok.  Stuff on the floor = blown ones that have already been replaced.

Feel the RAM with your fingers.  A dead giveaway that a RAM is bad is they get HOT!

I'd recap the power supply.  Heck, I'd recap all the boards.  The caps are almost 30 years old.  They're due.

[SirPeale]

Oh yes...I've seen worse corrosion.  You need to nip it in the bud, though.

Take out the board, and start LIGHTLY brushing the corrosion with a toothbrush dipped in vinegar.  Yes, vinegar.  It'll fizz. That's fine.  Wipe it with a damp paper towel and dry well.

[TheShanMan]

I couldn't see any chips labeled 4116. Which ones are they? I felt every chip on all the boards, and none felt hot. I am curious about a seemingly missing rom chip in picture 3. Is that normal?

I pressed that momentary switch on the sound board, and a couple of minutes later it started playing some music, followed by an explosion sound, and then repeating over and over. What does that mean?

I looked at that dangling red wire, and it connects to one of the terminals for that dangling coil. What am I supposed to hook it up to?

[Ummon]

Very nice condition. Quite worth it.

[Steve]

Is there a defender manual available online?

http://www.robotron-2084.co.uk/manualsdefender.html

Hope this helps 

[TheShanMan]

Thanks Ummon. Since I'm new to buying cabinets, I don't have a great feel for what is good condition or what I should pay for a certain condition, but Peale and RetroACTIVE were kind enough to offer advice to me based on the description I got yesterday. I also thought it was good condition for the money, but as a noob it's nice to get confirmation from others here.

Thanks to Peale for directing me to online manuals. And thanks to Steve as well (not sure if they're the same files yet, or if one set of files is better than the other). Looks like there's a lot that's defender related, and I have plenty of reading to do. So far this is pretty exciting stuff. Hopefully it continues to be exciting, rather than getting old and frustrating.

Oh, and can someone confirm for me that the PS isn't stock? Looks to me like the old one was scrapped and replaced.

[SirPeale]

I couldn't see any chips labeled 4116. Which ones are they? I felt every chip on all the boards, and none felt hot. I am curious about a seemingly missing rom chip in picture 3. Is that normal?

I pressed that momentary switch on the sound board, and a couple of minutes later it started playing some music, followed by an explosion sound, and then repeating over and over. What does that mean?

I looked at that dangling red wire, and it connects to one of the terminals for that dangling coil. What am I supposed to hook it up to?

The sound means your sound board appears to be working.  We'll get to that after we make sure everything else is working.  The sound board isn't necessary to gameplay, but we need to make sure everything else is working first.

I'm not seeing the dangling red wire.  I see the width coil, and the wires connected to it.

Let me say this: since it's currently working, DON'T SCREW WITH IT.  We can deal with other stuff in a bit.  Let's get the boards working.

The 4116 are the three banks of eight chips in the corner of the board.  Look closer, they should say 4116 on them, perhaps surrounded by other text.

[Level42]

I'll be following this thead closely as I'm also working on a Defender from a fellow collector here that's completely dead. Don't get any picture and all the 4 LED's on the rom board are on. PSU is replaced with a switcher and supplies are OK.

Just for the sake of it, try the reset button on the soundboard. When I did that, i dot the "Defender" sound constantly repeating until I powered it off.

[SirPeale]

Oh, and can someone confirm for me that the PS isn't stock? Looks to me like the old one was scrapped and replaced.

You're correct.  Someone took out the linear PS and replaced it with a switcher.

[TheShanMan]

Cleaned up the cpu/video board with vinegar and a toothbrush. Here's an after pic.

Only 4 of the ram chips have 4116 on them. The rest are something else. None of them get hot though.

I'm a little reluctant to pull the roms and re-seat them simply because they're kind of stuck in there. They will pop free with a little bit of effort but since they're 28 years old I don't know how worried I should be about breaking one. Am I being overly concerned?

What's the next step? Do I just need to buy a cap kit and start with that? Or are there any steps I can take now, before having to go down the road of replacing things (not that I wouldn't do the caps, but if I can get it running sooner than later I'd be happy!).

[SirPeale]

How are you removing the ROMs?  DO NOT use a chip puller.  Use a jewelers screwdriver.  Pry up on one end, then the other, walking the chips slowly up.

But I don't think you're having ROM issues.

Have you fired Defender up in Mame yet?  Check the startup sequence.  How does it compare to what you have?

[TheShanMan]

Actually I WAS using a screwdriver, but I was thinking "I wonder where my chip puller is", so I'm glad you said that before I found it.

I don't think I'm having a ROM issue (yet) either. There is NO startup sequence. It just turns on to that yellow hash screen and that is all it does.

[Kevin Mullins]

Clean and re-seat any socketed chips. (my $.02 on that part)

"dangling red wire"

Horizontal position jumper.
Connect to any of those three pins, whichever suits your needs.... Left , Center , Right.

[SirPeale]

Oh, THAT wire.  Sorry, didn't see it.  Yes, follow Kevin's advice.

I'd like to see some video of what happens when you turn it on, if that's possible.

In this picture:



it looks like you're getting rug pattern.

[TheShanMan]

Regarding the wire, I'll hook it up, but how would one decide which one to hook it to. It's not an arbitrary choice, is it?

Here's a better pic. I could try making a video but not sure what that would accomplish. All it would show is the screen showing this as soon as the monitor warms up. Let me know if this pic isn't adequate though.

And to bring attention to an old question again: is there no such thing as "rom 5"? I have 11 roms, numbered 1-12, with a hole at #5.

[SirPeale]

Just pick one of them for now.  It's a horizontal centering pin.  When you get a stable working picture you can adjust it to best fit.  When you recap the monitor likely you'd have to move it again anyway.

Oh yeah...as for the RAM, good that none of it is hot.  And as for the different numbers, sometimes manufacturers will have different numbers for compatible parts.  Not sure about 4116 RAM.  But you should trade the 4116 for 4164 anyway.  I'll be offering RAM and an adapter in my store soon.

[TheShanMan]

Are you suggesting that the ram may be part of my problem? Or just that it's a good thing to do, and in my case more preventative maintenance than anything else? And the caps - is a cap kit just "good to do" but nothing to do with my problem? I'm fully willing to spend the money to do it right, but just wondering if these are things that might be factoring into my problem or more of a "while you're at it, might as well do the caps and rams"?

Also note that I edited my last post with a better pic as you requested.

[Kevin Mullins]

And to bring attention to an old question again: is there no such thing as "rom 5"? I have 11 roms, numbered 1-12, with a hole at #5.

http://www.crazykong.com/pcbs/A%20-%20F/Defender.pcb.html

[SirPeale]

4116 RAMs on Williams boards are problematic.  They're a high-fail item.  If there aren't any bad RAMs on that board I'll be surprised.  It's because they take multiple voltages - +5V, -5V and +12V.  Conversely, 4164’s only need +5v and runs much cooler.

Recapping the monitor makes sense because the originals are 30 years old.  They're not getting any better.  But since your monitor is currently working, I'd concentrate on getting the boards working first.

The RAM may very well be part of the problem.  Check the ROM board, there are four LEDs.  What do they do when the machine is booting?  You can open the coin door and look inside to see what it's doing after hitting the power switch.

[SirPeale]

And yes...there's supposed to be an empty hole there.

Another thing to consider is the damage from the battery.  It looks like the traces may be eaten away, you may have to run some jumper wires.

[TheShanMan]

The RAM may very well be part of the problem.  Check the ROM board, there are four LEDs.  What do they do when the machine is booting?  You can open the coin door and look inside to see what it's doing after hitting the power switch.

The LED's come on and stay on. If the ram may be part of the problem (even though none are hot), how soon will you have them available? I'd like to keep this ball rolling as much as possible so I can get it up and running at the soonest possible time, so I would love to order them from you but I hope I won't have to wait long.

Another thing to consider is the damage from the battery.  It looks like the traces may be eaten away, you may have to run some jumper wires.

I'll try some continuity tests to see how it is.

Did that new monitor pic tell you anything?

[Level42]

... I'd like to keep this ball rolling as much as possible so I can get it up and running at the soonest possible time, so I would love to order them from you but I hope I won't have to wait long.

You'll need to be a bit more patient my friend, this sounds like a problem on the mainboard to me. You'll have to check if the watchdog is constantly tripping the reset of the CPU. From there, you may find lot of problems that you'll have to be experienced in finding in board errors for.
There's no "magical solution" to a problem like this. I doubt it's the RAM because the board doesn't even come up right now. I have the same problem with a Defender I'm working on here right now.

If you're really in a hurry, I'd reconsider the new multi-williams by JROK. Although I can understand why you want to try to repair the original hardware first.

[TheShanMan]

I understand. I just mean that I hope to avoid unnecessary delays. It's not like I'm sticking this in the corner to deal with at some later time. That's all.

If you're having the same problem then I hope you'll be posting your findings.

I'll look into the watchdog circuitry. I saw some info on that in the manuals, so hopefully it's enough to help me do some checks. I don't have an o-scope so unfortunately I'm limited for any tests that need one.

I appreciate all the hand-holding. I've already learned a lot!

BTW, I checked for continuity of the ground at the batteries and various other parts of the board, and it doesn't appear that corrosion has broken any of the circuits.

[RetroACTIVE]

+ It appears that your system isn't even properly initializing... this looks more like a voltage/connector issue at the moment.  Or your switcher's rise time is way too slow...
+ If it were a RAM problem... you would at least get a rug pattern...
+ Check voltage on each of your boards... (not at the power supply)...
+ Looks as if this unit has had some moisture issues... you need to check the ribbon cable that connects the ROM board... pull it out... clean the pins and put it back on...
+ Your batteries may not even be working since it appears as if the holder is way corroded.  They are most likely not the cause of this issue you are having.  The batteries are there to provide back up voltage to the CMOS RAM.

 

[SirPeale]

+ If it were a RAM problem... you would at least get a rug pattern...

The rug pattern is part of the RAM test.  If the RAM is bad, you won't get proper rug pattern.

I had one bad RAM in my Defender, and got yellow bars but not a bit of rug pattern.  Replaced that RAM and finally was able to go into onboard test.

*DEFINITELY* check your voltage on the board.  I'm sure your power supply needs recapping.  Remember...30 year old caps aren't your friends.

*DEFINITELY* clean any socketed chip legs.  If you don't have a fibreglass pencil, get one.  BE GENTLE.  Clean both sides of the legs.

*DEFINITELY* check solder joints on the PCBs as well as connectors.  Williams connectors are known to be problematic.

[TheShanMan]

Guys, this gives me some good stuff to try. From a quick search it looks like I can get a fiberglass pencil at an auto parts store? I'll go there and get one - never heard of them before.

Peale, remember that my power supply was replaced with a switcher, so caps wouldn't be an issue on it I assume. I am getting proper voltages at the supply, but I haven't checked rise time or voltages at various points on the board.

Thanks for the suggestions!

[SirPeale]

Guys, this gives me some good stuff to try. From a quick search it looks like I can get a fiberglass pencil at an auto parts store? I'll go there and get one - never heard of them before.

That's correct.  Excellent for cleaning corrosion off...well, pretty much anything.  Works great for electronics.  Be careful when cleaning the dust, they're glass fibres!  They will get in your skin.  I have one in my thumb for a few days now, it's particularly annoying. 

Peale, remember that my power supply was replaced with a switcher, so caps wouldn't be an issue on it I assume. I am getting proper voltages at the supply, but I haven't checked rise time or voltages at various points on the board.

I did forget that.  They could be an issue if it's running like crap.  Peer in the vents and see if they're domed.   If they are replace them, or replace the PS.

Definitely check the voltages on the board. 

As to when I'll start carrying 4164 and the adapters, I'm working out a deal right now for the RAM, but I need to raise the capital for the initial purchase.  Hopefully not long.

[TheShanMan]

The microprocessor has 4.96V at pin 7, but I noticed that the reset pin, 37, is at 0.14V, so that would indicate a reset or watchdog problem, right? I want to try to figure out what's going on with those circuits, but while the manual has circuit diagrams, it's hard to follow the circuit on the board itself. I don't see anything that connects the dots from the circuit diagrams to the board.

[SirPeale]

Getting down to this level is beyond my scope at the moment.  You may want to ask about that on RGVAC.

[Level42]

The microprocessor has 4.96V at pin 7, but I noticed that the reset pin, 37, is at 0.14V, so that would indicate a reset or watchdog problem, right? I want to try to figure out what's going on with those circuits, but while the manual has circuit diagrams, it's hard to follow the circuit on the board itself. I don't see anything that connects the dots from the circuit diagrams to the board.

Use the pin numbers and follow the diagram lines to see where they go then check out the pin number there again. Now you can measure between those points.

About the reset: Is there a way to disable the watchdog ? I know Atari boards have that feature. You have to short a certain "test" point to GND to disable the watchdog.

For me, even that didn't work on my Centipede board.
(Check out my Centipede thread for the full story). The Centipede had a completely frozen screen full of garbage. Most people pointed me to either RAM or ROM problems. However, Mark Spaeth gave me the right clue. He said that it wasn't a RAM problem, because the board didn't even come to executing the first steps from the program in the ROM. Which makes sense. When a CPU starts, (almost) the first thing that it does is adress the first ROM adress and execute the code stored there. He told me my board didn't even reach that stage. So I had to look elsewhere. After trying the watchdog disable (which didn't help), I shorted a +5V point on the board (test-point) to the reset pin of the CPU. First I did it very momentarily, but it was already enough to get a frozen (but complete play field. Next I held it shorted a little longer, and the board was running (as long as I shorted the +5V to the reset pin, as soon as I released it it naturally froze again because of the reset becoming active again) ! I'm not sure if this is a safe method, but it did point me in the right direction, there was a problem within the watchdog/reset circuit itself !
Now, it takes quite a bit of time for a Williams board to start the game/program, but if you'd get (part of) a rug pattern that _could_ point into the right direction.

The thing is: when the watchdog is resetting, the problem can be almost anywhere, because the CPU crashes at some point. There could be a problem in the databus or adressbus and since those busses basically are "everywhere" on the PCB(s) (incl. the CPU itself) there's no telling what may be wrong. It takes quite some experience (and dedicated testing equipment !) to find the (if not more !) problem.

Your best bet is following the suggestions for what other people have experienced as causes for the same sort of problems.

That's why that new multi-board is such a great option. For the cost of a repair, you get a brand new board with modern technology PLUS extra games without loosing originality in game play. It's a serious "back-up" option.