Defender stuck in book keeping

jehuie

Well-known member

Donor 2011
Joined
Sep 8, 2007
Messages
10,947
Reaction score
1,672
Location
Martinez, California
So I bought another Defender so I'll have parts to swap into my other Defender project. But I need to get this one to play first. It has a very clean looking set of boards. Power supply is completely rebuilt. All new caps on everything. New interconnect cables.

The batteries are new and when I measure them at the board I get 4.6 volts. LED's flash when I power up and go back out as they should. But it always goes directly into book keeping. Following the directions in the manual won't ever let me get back into "Game over" mode...it just returns to book keeping instead.

Thoughts on where to start with this?

Thanks!
 
Replying to my own thread now...

I swapped this board into my old broken Defender and got a rug pattern. Swapped the rom board too and....it works. And does NOT go into book keeping.

So this means there's something in the other cab making it go into book keeping. What could that be? Hmmmmm.
 
Replying to my own thread now...

I swapped this board into my old broken Defender and got a rug pattern. Swapped the rom board too and....it works. And does NOT go into book keeping.

So this means there's something in the other cab making it go into book keeping. What could that be? Hmmmmm.
Bad ground?
 
Replying to my own thread now...

I swapped this board into my old broken Defender and got a rug pattern. Swapped the rom board too and....it works. And does NOT go into book keeping.

So this means there's something in the other cab making it go into book keeping. What could that be? Hmmmmm.

Swap them back and see if it works now. Could have been a loose connector.
 
Swap them back and see if it works now. Could have been a loose connector.

Could be. I'll check that. The guy who sold it to me told me the new board will reset once in a while and it just did it. :( In the middle of a game it just restarted. Rug self test and then started up again. Errrr.

Defender boards seem to be my nemesis. Who would be good to send both sets of boards off to for repairs? And how much should I expect something like that to cost if I go that route?

They both look clean but have issues.
 
Could be. I'll check that. The guy who sold it to me told me the new board will reset once in a while and it just did it. :( In the middle of a game it just restarted. Rug self test and then started up again. Errrr.

Defender boards seem to be my nemesis. Who would be good to send both sets of boards off to for repairs? And how much should I expect something like that to cost if I go that route?

They both look clean but have issues.

Resets could be anything, but the first things I would look at are:

1) Power Supply
2) Connectors on the Harness
3) RAM
4) Ribbon Cable between ROM board and CPU board.

You might as well finish learning how to fix them yourself if you plan on keeping Williams games :D

You might also consider mounting a FAN that blows air onto the PCB.

EDIT: Have you gone through the self tests? Those might give you a different result then just the normal boot tests.
 
Mine does that sometimes. Check the white door switch inside the coin door area. If that switch is bad or not reading right it goes into book keeping.
 
The batteries are new and when I measure them at the board I get 4.6 volts.

Don't bother measuring the voltage at the batteries, measure at the CMOS chip. Pin 22 for (+) and pin 8 for ground.

There are a number of reasons the voltage can be good at the batteries and low or non-existant at the CMOS chip.

Another common issue is the memory protect switch. Check the continuity between the memory protect connector (the 4 pin connector with 1 wire usually red that connects between the power and video connectors) and ground. You may have to get someone to help open & close the coin door while you hold the meter probes.

ken
 
Don't bother measuring the voltage at the batteries, measure at the CMOS chip. Pin 22 for (+) and pin 8 for ground.

There are a number of reasons the voltage can be good at the batteries and low or non-existant at the CMOS chip.

Another common issue is the memory protect switch. Check the continuity between the memory protect connector (the 4 pin connector with 1 wire usually red that connects between the power and video connectors) and ground. You may have to get someone to help open & close the coin door while you hold the meter probes.

ken

Ran home at lunch and took a look. Measuring at the battery holder I got 4.61 volts but measuring at pin 22 it dropped to 4.25. Is that acceptable? Also, I used the corner of the board for ground rather than pin 8...not sure if that makes a difference.

Then I went to check continuity at the memory protect switch and noticed that the red wire was disconnected so I soldered it back on. I played a game and it reset on me in the middle of the game again.

Didn't have time to go further though. :(
 
Ran home at lunch and took a look. Measuring at the battery holder I got 4.61 volts but measuring at pin 22 it dropped to 4.25. Is that acceptable? Also, I used the corner of the board for ground rather than pin 8...not sure if that makes a difference.

Then I went to check continuity at the memory protect switch and noticed that the red wire was disconnected so I soldered it back on. I played a game and it reset on me in the middle of the game again.

Didn't have time to go further though. :(

4.25 is way too low. It needs to be around 4.7 or higher.
 
4.25 is way too low. It needs to be around 4.7 or higher.

Interesting. Even at the battery holder it's low then. I would think that with 3 batteries at 1.5 volts each, 4.5 volts would be acceptable. I have a lithium battery kit so maybe I'll try throwing that on there to see if it makes a difference.

Is it normal to have that much of a drop in voltage between the holder and the chip though?
 
Interesting. Even at the battery holder it's low then. I would think that with 3 batteries at 1.5 volts each, 4.5 volts would be acceptable. I have a lithium battery kit so maybe I'll try throwing that on there to see if it makes a difference.

Is it normal to have that much of a drop in voltage between the holder and the chip though?

Oh! I was thinking you were measuring with the power ON, not from the battery. Ignore what I said :eek: Sorry.
 
Ok so here's the current status:

I checked the interlock switch and the red wire for continuity and to be sure the switch is operating correctly. It's fine.

I swapped out the batteries and put the lithium battery in their place.

The guy who had it before me claimed that he swapped out all the ribbon cables to try to fix this problem before. They look newish but it's hard to tell for sure.

I played about 5 games in a row and just as I walked away it reset and went back to book keeping.....again. Argh. I'm tired of Defender boards.
 
I need to keep an eye on this thread. Mine did the same thing, and hopefully never does again. Brien fixed it. Brien is awesome.
 
I need to keep an eye on this thread. Mine did the same thing, and hopefully never does again. Brien fixed it. Brien is awesome.

Brien who? And can he fix mine? Did he tell you what kind of voodoo he did?

Edit: Oh, you mean Brien King don't you? Duh.
 
Last edited:
Ok so here's the current status:

I checked the interlock switch and the red wire for continuity and to be sure the switch is operating correctly. It's fine.

I swapped out the batteries and put the lithium battery in their place.

The guy who had it before me claimed that he swapped out all the ribbon cables to try to fix this problem before. They look newish but it's hard to tell for sure.

I played about 5 games in a row and just as I walked away it reset and went back to book keeping.....again. Argh. I'm tired of Defender boards.


I think the Book Keeping issue might be a red herring. I would try to figure out why it's resetting first.

When it resets, it goes into book keeping. If you let it sit for awhile, then power it back on, does it still do that, or do you need to cycle through the settings first? (or can you even get out of book keeping?)

If it works fine after letting it sit for awhile, then it could be heat related. If it is, you can start to feel around for really hot chips (you'll know it when you feel it), and use a can of Freeze Spray to cool down suspect chips to see if the game stops resetting.
 
I agree about it not having to do with the book keeping so much. Normally it resets back into play mode but this time it went to book keeping. It doesn't seem to be heat related. Sometimes it will reset within a couple minutes of turning it on for the first time. Other times it will play for an hour with no problems. Someone suggested I try to make it reset by wiggling some cables. I'll give that a shot in the morning.
 
The other thing to try is to (carefully) measure the voltage at the four corners of one of the RAM chips, they should be +5V, -5V, +12V and ground. The voltages should be
Pin 1 = -5V,
Pin 8 = +12V
Pin 9 = +5V
Pin 16 = Ground
The pins are numbered starting in the upper left corner (the side with the notch), going counter clockwise. If any of them are low or are fluctuating more than 0.1 V you need to check your power supply.

ken
 
The other thing to try is to (carefully) measure the voltage at the four corners of one of the RAM chips, they should be +5V, -5V, +12V and ground. The voltages should be
Pin 1 = -5V,
Pin 8 = +12V
Pin 9 = +5V
Pin 16 = Ground
The pins are numbered starting in the upper left corner (the side with the notch), going counter clockwise. If any of them are low or are fluctuating more than 0.1 V you need to check your power supply.

ken

Thanks. I would try that except that I screwed something up. I officially am the worlds most suckiest board repair person. If there was a way to give myself negative reputation I would.

Someone mentioned that I should try wiggling the cables to see if I could get it to reset...which would indicate cold solder joints on the header pins. So I did that but couldn't get it to reset. Well, I thought why not just go ahead and redo the solder on those pins just in case. So I pulled the board, removed the solder and put new solder on each of the pins. Checked it all over closely and it looked good.....

Plugged the board in and fired it up and now all I get is jail bars and no sound at all. I killed it. How the heck did I kill it from just touching up some solder? Ugh. I went back and looked it all over cloely with a magnifier but I don't see any solder bridges or anything like that.
 
Plugged the board in and fired it up and now all I get is jail bars and no sound at all. I killed it. How the heck did I kill it from just touching up some solder? Ugh. I went back and looked it all over cloely with a magnifier but I don't see any solder bridges or anything like that.

It's not dead, it's just resting.

Check the Continuity between pins, don't trust your eyes. Redoing the pins, you might have created a new cold solder joint, so check your soldering for consistency. Post a picture of what you did as well.

Check for excess solder that might have fallen on to a different part of the board.

The connector itself could be bad. Are the pins on the header clean?

What are the voltages now? Did they change?
 
Back
Top Bottom