Defender needs help booting up

Malice95

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So I picked up a defender today. Initial board tests are okay
when I press the reset buttom on the main board I get 4 LEDs.

Problem is it never fully boots and I cant get it into test mode.

I tried reading the toubleshooting guide. but
http://www.arcade-museum.com/manuals-videogames/D/Defender-Later-Series-Setup-Booklet.pdf

I cant figure out what the heck they are talking about when they
say "From game over, Press ADVANCE in manual down" ? Their are
3 button in the coin door area that arent labeled. but no matter what
I press I cant get into test mode.

Here is what is going on the screen as it boots. It just cycles over and over.

http://www.youtube.com/watch?v=qijJoWpmuqI

Any suggestions?

Thanks,
Malice95
 
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So I picked up a defender today. Initial board tests are okay
when I press the reset buttom on the main board I get 4 LEDs.

Problem is it never fully boots and I cant get it into test mode.

I tried reading the toubleshooting guide. but
http://www.arcade-museum.com/manuals-videogames/D/Defender-Later-Series-Setup-Booklet.pdf

I cant figure out what the heck they are talking about when they
say "From game over, Press ADVANCE in manual down" ? Their are
3 button in the coin door area that arent labeled. but no matter what
I press I cant get into test mode.

Here is what is going on the screen as it boots. It just cycles over and over.

http://www.youtube.com/watch?v=qijJoWpmuqI

Any suggestions?

Thanks,
Malice95

this is the label you are missing on your coin door switches bracket. it will help you with the purpose of each button.
http://cgi.ebay.com/Williams-System...912?pt=LH_DefaultDomain_0&hash=item43a10a1f08
one of the other arcade parts selleers also had these - maybe mikesarcade IIRC ?

the middle button is the Auto/Manual button. it is a push button toggle. when pushed and it is down, it means MANUAL (DOWN) when it is pushed and it is up, it means AUTO (UP).. the point is, when they say From game over, Press ADVANCE in manual down, pres the Auto/Man (middle) button DOWN, then press ADVANCE. took me a few goes when i first got defender to work out the sequence, the ADVANCE button is on the ...

i'm trying to find a better pic i had to show the orientation of the buttons/label.
 
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ADVANCE is typically the furthest button from you when the door is open.
 

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Well gave it a shot.. nada. Now matter what combinations of advace and up/down I
do when. The game totally ignore the input.

Any suggestions on what RAM might be bad? The reason I ask is I have another
board set (unknown if it works) and I already tried swapping the ram board only
and it got worse.. I didnt even get the rug pattern. So narrowing it down to
a couple chips would be ideal.

Does the game REQUIRE batteries to function? Someone removed that battery
clips on the board.

Malice95
 
You're not getting far enough in the boot sequence to get into diags, so don't worry yet about advance up/manual down. You have a continuous rug pattern, which can be caused by a number of different things either on the CPU board or ROM board. Start by carefully checking the voltages at all four corners of one of the RAM chips on the CPU board. The game will run without batteries, but will boot up in audit mode.
 
and I already tried swapping the ram board only
and it got worse..

The RAM is on the main CPU board..... not the smaller ROM board which has the ribbon cable going to it.

The problem you have could be many number of things.
Bad voltages.
Bad ribbon cables.
Bad RAM.
Bad ROM.
Bad CPU board.

I generally start by checking all voltages, re-seating/re-crimping all ribbon cables, re-seating all socketed chips.

EDIT: I see AMG mentioned some of this stuff already.
 
The seller gave me an early model board set with the game. The board set in the
game is a later set. I switched all the 4116 ram from the early board to the late
board and it changed at least. The pattern changed from RUG-RUG-blue/pink strip- repeat
to RUG-RUG-solid blue-repeat.

The power is good +5.2, -5.0, +12.4. its a modern switcher. I suppose
I should suspect the 7474 chips as well. They are in sockets so easy to
replace.

Are the ROM chips compitable from early to late system boards?

Thank you fior the source for 4116 chips. How about 7474 chips?

Malice95
 
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WoHO Its Alive!

I used the other rom board I had and methodically swaped each
rom chip looking for a difference. Of course as it was the very last
chip I swaped.. and the game came up. I ran through all the
tests using the test buttons and everything tested okay.

I played it for a couple seconds and noticed a couple things.

The leaf switch buttons are really soft. I assume its just a matter
of rebending the leaf switches for better button return. So a little
bending and they feel better.

The game doesnt register down. I have one wire on the control
panel harness that isnt connected to the input board connector.
I checked out the schematic and hooked it up..

100% functional now!

Couple questions since I havent played this game in ~25 years.

The joystick feels really soft. Should it have springs in it to
return it to center (dont have any) or is it just the leaf springs
to do this?

When the game is running I notice a small band of multi colors
at the top edge of the monitor. Is this normal? I seem to remember
this from the game but my memory could be faulty.

I set freeplay in the settings but I guess it doesnt maintain those
without batteries between power cycles?

I dont have a batter holder on the board so I will need to solder one
in. Is it just a matter of wiring in 3x 1.5 v batteries into the + and -
leads on the board? Or do I need a diaode or resistor? I guess I
could install D batteries.

Malice95
 
I'll try to cover some of the questions:

1) Should it have springs in it to
return it to center

No. What it has are two spring steel strips that are between the pivot rod and the leaf switches. If that is missing a common operator hack (since nobody I have found stocks those steel strips) is to cut a hacksaw blade to length and drill the mounting hole so that it mounts in place of the spring steel.

2) When the game is running I notice a small band of multi colors
at the top edge of the monitor. Is this normal?

Yes. The video RAM is just a band of RAM in the CPU's address space. If the timing is slightly off (which it usually is) you get that coleor changin strip. That is just some non-video memory being displayed as if it was video memory. Just adjust the vertical height and/or vertical centering of your monitor to push it off screen.

3) I set freeplay in the settings but I guess it doesnt maintain those
without batteries between power cycles?

Correct. You need batteries to hold the values in the CMOS RAM. Defender used an older CMOS RAM and people who have done the lithium battery mod (link) have reported mixed results. On Defenders, I usually go to Radio Shack and get the plastic 4 AA battery holder and rewire it for 3 batteries.

Lithium "button" battery holder (link) RS#270-009
4 AA Battery holder (link) RS#270-391

There is also some site that is selling 3 AA sealed battery holders, so that if the batteries explode they don't contaminate the boards, but unless you are buying other stuff, shipping will be 3x to 4x the price of the holder.

One note, on most battery holders they are designed to have the batteries flip from end to end. On the Williams battery holders that all face the same direction and the traces on the board connect the + ends to the - ends. With the RS battery holder, you only need to connect the + lead to the first + contact and the - lead to the last - contact (that one connects to the wide ground trace that circles the board).

ken
 
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