Williams System 11c CPU LEDs - all 3 are out????

[judgeboz]

Got a Swords of Fury pin that has a CPU issue somewhere. Ive noticed that the 3 LEDs on CPU are not on or flashing at all - I would have expected at least one would work and not all 3 out Also the 1 and 2 player displays are showing all segments on for all digits - 3 and 4 players are off.

Also, I noticed when I press each of the buttons on the LHS on the CPU board - 1 tests the sounds (yep got some sounds) and other the CPU - when pressed I got nothing (eg again nothing from all 3 LEDs).

Here's what I have done/checked to date:

1. checked all fuses

2. CPU
2.1 unplugged all plugs on the CPU except for J17
2.2 tested J17 pins 4,5 and 6 - got +5v
2.3 tested J17 pin 8 - got -12v
2.4 tested J17 pin 9 - got +12v
2.5 TP2  - got +5v
2.6. tested for +5v on the following chips - all got +5v:
2.6.1 U15 pin 8
2.6.2 U26 & U27 pin 28
2.6.3 U10, U38, U41, U42, U51, U54 pin 20 

So that this point, Im thinking its maybe one of the chips but which one? Who sells these chips for System 11c games - eg CPU (6802 or 6808), RAM (2k by 8 CMOS static 24 pin)?

cheers
John

[Caveoftreasures]

Boz, when Beaky (Andrew) discovers this post, he shld have an answer for u. Andrew has a excellent Swords of Fury. I am also sure he can organise the parts u need as well. His machine is working fine, and since he is a fully qualified pinball tech (there aint nothing he cant do), he shld have it running for ya in no time, via a email n few suggestions.

Just PM Beaky. He loves PM's. He will see this post when he logs on, sunday arvo. 

[beaky]

had a quick look at a sys 11 cpu and noticed that pin 20 on U51 and U54 are on the same track as the 5vdc led. (these are the closest chips on the 5 volt rail that you have tested to the 5vdc led)
if you are getting 5vdc at these points your 5vdc led should light.(but as you have said all leds are out)

have you tested that the cpu is grounded properly?

to do this check that you have 0 ohms from the the braided ground strap to TP1 (GND) (machine turned off)
then put your multimeter across TP1 and TP2 and check if you have 5vdc (machine turned on)

we will first try and get the 5vdc led going.

let me know how you go and we will go from there

[Marty Machine]

Howdy,

I have a 'swords of fury' too, if we need to compare anything between pins?

MM

[beaky]

Howdy,

I have a 'swords of fury' too, if we need to compare anything between pins?

MM

well well well, its THE machine (no i am not calling you the bride of pinbot)
Hi MM. good to hear from you budy. 
us SOF owners have to stick together, there aint many of us around. lol

[Marty Machine]

Yep, the machine is here.....

Funny how another SOF has turned up, i thought we had the only 2 in the coutnry hehehe.

MM.

[beaky]

if i am not mistaken this one was sold for $600

it would be nice to see some pics of it.

[Caveoftreasures]

Beaky, what if it were as silly as the 3 x LED's being blown, how does boz test the 3 x LED lights.
or should i just shut up since i have no idea of what i am talking about.

you guys look for complex reasons, i look for the simple ones. if that makes sense. 3 x blown leds ?  wishful thinking. 

[Marty Machine]

Assuming the 3 leds are dead (for whatever reason) does the machine have any life?


Forgot to add.....when you measure the voltages on the chips etc, do you have the negative lead on a common ground point somewhere on the board?

It's preferable to measure the volts (and ground) on the chip pins to prove 5v/0v is actually arriving at the chip.
There can always been a broken ground-track between the common board ground and the chip-pin....

May be go re-measure your chips?

MM.

[beaky]

Assuming the 3 leds are dead (for whatever reason) does the machine have any life?


Forgot to add.....when you measure the voltages on the chips etc, do you have the negative lead on a common ground point somewhere on the board?

It's preferable to measure the volts (and ground) on the chip pins to prove 5v/0v is actually arriving at the chip.
There can always been a broken ground-track between the common board ground and the chip-pin....

May be go re-measure your chips?

MM.

correct MM
that is why i have asked him to check the resistance from the ground strap to TP1 and then voltage from TP1 to TP2.
after he confirms that there is a ground to tp1 then i was going to ask him to check the voltage on pin 1 to pin 20 on U10, U38, U41, U42, U51, U54

you are right on track MM 

[Marty Machine]

Not a fan of test-points, they only indicate a voltage/signal is getting to the test-point, and not to the chip(s). 

[judgeboz]

Thanks guys for getting onboard to help me out.

Ive done as requested here:
1. braided ground strap to TP1 (with the game off) - got 0 ohms
2. multimeter across TP1 (black lead) and TP2 (red lead) with the game on - got 5v.
3. retested the chips for 5v using TP1 for ground and a little different now:
3.1 U15 - got 5v
3.2 U26 and U27 - got 5v
3.3 U10, U38 - got 5v
3.4 but U41, U42, U51 and U54 the results varied from 2v to 5v. I forgot to mention I replaced the battery holder as the batteries were corroded and it looks like its on the legs of these chips too. It doesnt look to bad - do I use 50% vinegar and warm water mix to clean it up?

[Marty Machine]

I'd say 2v or anything less than 4.75v (when it should be 5v) will definately be a problem.

What chips are U41, U42, U51, U54 ? are they 74xx, 68xx etc? (1 dont have a fury/sys11 manual handy at the moment).

MM

[beaky]

yep give it a clean up.

if you can take a few pics of both sides of the pcb in the acid damaged areas.
you may have several tracks that need to be repaired.

also you will need to remove all the corrosion and clean the board in that area so the copper tracks are nice and shiny, then you will have to check that all the tracks in that area are not corroded threw.

then after you have repaired the damaged tracks you will need to seal the pcb with some clear pcb laquer.

dont do any thing yet. i will see if i can find some posts on this subject and post the links here.

[beaky]

the process of repairing a acid damaged pcb is here http://aussiepinball.com/index.php?topic=2343.0
its not for sys 11 but it should help