Picked one up today, great PF, fairly good BG, appears to be all new plastics, as they are in perfect shape.  It turns on, but doesn't enter into attract mode, or start new game.  Found diode leads touching center light tracking, and some broken wires/diodes already.

Displays are showing strange sequences, should be interesting...

Aaron

Sounds like it's coming up in audit mode. Audit mode on a Firepower will show 1497 2 (or something similar) on the displays. Change your batteries and see what happens (assuming they're not horribly corroded.... in which case you've got bigger problems).

From http://www.pinrepair.com/sys37/index1.htm#battery....

Booting into Audit Mode Explained.
On system4 to system7 pinballs all the game's options and audits are stored in CMOS memory (system3 is a bit different, and is explained below). If the batteries are dead, or the battery holder is damaged, or the blocking diode D17 has failed, or there's a bad IC19 RAM 5101 chip, or battery corrosion has damaged the CPU board, the game will power up into "audit mode". Audit mode is shown in the picture above, and is saying that the game has lost its CMOS memory, and there's a problem. It's a big red flag when the game is turned on, since the game goes into audit mode instead of attract mode (game over mode). Operator assistance required!

Quoted from cooke

Sounds like it's coming up in audit mode. Audit mode on a Firepower will show 1497 2 (or something similar) on the displays. Change your batteries and see what happens (assuming they're not horribly corroded.... in which case you've got bigger problems).

From http://www.pinrepair.com/sys37/index1.htm#battery....

Booting into Audit Mode Explained.
On system4 to system7 pinballs all the game's options and audits are stored in CMOS memory (system3 is a bit different, and is explained below). If the batteries are dead, or the battery holder is damaged, or the blocking diode D17 has failed, or there's a bad IC19 RAM 5101 chip, or battery corrosion has damaged the CPU board, the game will power up into "audit mode". Audit mode is shown in the picture above, and is saying that the game has lost its CMOS memory, and there's a problem. It's a big red flag when the game is turned on, since the game goes into audit mode instead of attract mode (game over mode). Operator assistance required!

Same problem for me on Gorgar. Changed the battery holder, (corroded), and new batteries too. All good now! Good luck!

Pete

I recall the display having numbers similar to that, so that is a good sign then.  

They original battery holder was removed off the board, and they have added a satellite holder, however it is just tucked under some cables high on the backboard haha, unfastened.  The batteries were not corroded though.

The previous owner stated he was told by a friend who “knew pinball” that it needed two coils as well.  He said the ball feeder coil would get really hot and start to smell.  When I looked at it, there is black burn lines around this coil, where the wires wrap around the coil just under its cover.

From the little I know, coils don't usually go.  Could this one be indicating another problem?  It wasn't activiated at the time, but I guess that could be due to audit mode.

I’ll try replacing the batteries first, and see what this does, and maybe post some pics after.  There are clearly other problems, as there were at least two broken diodes, and many more that I had to straighten out from touching other leads.  

...would almost suck if that was the only problem though, as this was going to be my tester for bigger problems.  I'll have to let me puppy run wild inside for a while, and then start again =)

Aaron

Read this section carefully, too:
http://www.pinrepair.com/sys37/index3.htm#trans2

I've had a Wms Flash with burning coil problems, and it eventually turned out to be teh 7408/7402 chip behind the PIA for coils.  Good luck!
Daniel

Quoted from Atomicboy

I recall the display having numbers similar to that, so that is a good sign then.  

They original battery holder was removed off the board, and they have added a satellite holder, however it is just tucked under some cables high on the backboard haha, unfastened.  The batteries were not corroded though.

The previous owner stated he was told by a friend who “knew pinball” that it needed two coils as well.  He said the ball feeder coil would get really hot and start to smell.  When I looked at it, there is black burn lines around this coil, where the wires wrap around the coil just under its cover.

From the little I know, coils don't usually go.  Could this one be indicating another problem?  It wasn't activiated at the time, but I guess that could be due to audit mode.

I’ll try replacing the batteries first, and see what this does, and maybe post some pics after.  There are clearly other problems, as there were at least two broken diodes, and many more that I had to straighten out from touching other leads.  

...would almost suck if that was the only problem though, as this was going to be my tester for bigger problems.  I'll have to let me puppy run wild inside for a while, and then start again =)

Aaron

I replaced the batteries, no go.  The batteries that were in there looked new, so I checked these, and they are new.  Someone has tried the simple things in getting this to work already it appears.

I then started testing for voltage from the batteries to the IC19.  Nothing – so I figured out that the battery pack was the issue.  On closer examination the + contact was corroded, so I cleaned this, and power flowed as it should from this, through the blocking diode, and everything checked out on pin 22 as well.

At this point, still audit, however the display numbers are not just displaying the message, they are flickering, and some of the “1497” will go in and out (this was the case prior to these fixes as well”.  I tried the power off/on test, and this then got it through audit (and has been out of this ever since).  At this point, the ball release coil was continuously on.  This is the coil that the previous owner was told they needed to replace.  This is also the coil that shows burn marks.  It heated up rather fast.

Clearly the coil works fine.  At this point, I assume there is one (or more) shorted transistors.  I didn’t have time to go through the whole driver board, however I tested about half, and found one small 2N4401 at Q20 that appears to be no good. This is a start, as this is the left hole kicker, which the previous owner stated never worked, and they put tape over to stop it from sitting in there

I am wondering now if this is the IC1 7408 chip, as McMean stated, as the ball release (permanently on) and the left kicker (not working at all, bad 2n4401) are both on this chip.  The only other two solenoids on this chip, Q17 and Q19, are both unused.

I’m thinking there was a problem that initiated with the left kicker 2N4401 tran, causing the kicker to not function, eventually causing the 7408 to fail, which in turn is now causing the other solenoids on this chip, only being the ball release to not function properly.

Let me know what you think.  Also, I’m not entirely sure how to test the 7408?

Cooke – can I buy all this stuff at Aplus?

Aaron

Great progress... sounds like 7408 could very well be the culprit.  If you can't get it at APlus, then use Great Plains Electronics - really great service and very reasonable shipping.  
You can test the 7408 with a logic probe... I believe it's in the pinrepair guide somewhere but I can't access it right now to find it.

Daniel

Quoted from Atomicboy

I replaced the batteries, no go.  The batteries that were in there looked new, so I checked these, and they are new.  Someone has tried the simple things in getting this to work already it appears.

I then started testing for voltage from the batteries to the IC19.  Nothing – so I figured out that the battery pack was the issue.  On closer examination the + contact was corroded, so I cleaned this, and power flowed as it should from this, through the blocking diode, and everything checked out on pin 22 as well.

At this point, still audit, however the display numbers are not just displaying the message, they are flickering, and some of the “1497” will go in and out (this was the case prior to these fixes as well”.  I tried the power off/on test, and this then got it through audit (and has been out of this ever since).  At this point, the ball release coil was continuously on.  This is the coil that the previous owner was told they needed to replace.  This is also the coil that shows burn marks.  It heated up rather fast.

Clearly the coil works fine.  At this point, I assume there is one (or more) shorted transistors.  I didn’t have time to go through the whole driver board, however I tested about half, and found one small 2N4401 at Q20 that appears to be no good. This is a start, as this is the left hole kicker, which the previous owner stated never worked, and they put tape over to stop it from sitting in there

I am wondering now if this is the IC1 7408 chip, as McMean stated, as the ball release (permanently on) and the left kicker (not working at all, bad 2n4401) are both on this chip.  The only other two solenoids on this chip, Q17 and Q19, are both unused.

I’m thinking there was a problem that initiated with the left kicker 2N4401 tran, causing the kicker to not function, eventually causing the 7408 to fail, which in turn is now causing the other solenoids on this chip, only being the ball release to not function properly.

Let me know what you think.  Also, I’m not entirely sure how to test the 7408?

Cooke – can I buy all this stuff at Aplus?

Aaron

hmm used the diode tester on my mm, 7408 appears to be good.  Could the small transistor on the left hole kicker be the issue causing overvoltage in the chip, causing the ball release coil to be permanently on?  I wouldn’t think that would be the cause...

I checked, and there a bunch of header pins that are cracked and could use new solder.  Again, I wouldn’t think this would be the immediate cause either, as a non-connecting pin would not cause the coil to be “on” would it?  That would cut the circuit, where the bad transistor would short it, right?

Unless the diode setting test for chips is not foolproof, it would appear the only issue found is the small 2N4401 at Q20.  It is still suspect though that the only two issues known at the present (left hole kicker, ball release) are both on the same chip...

I guess from here my only options are to replace the Q20, re-flow the header pins, and see from there, oui oui?

Aaron

I'm no expert, but I believe testing a 7408 with a DMM diode tester wouldn't be an accurate way to test... I believe you need a logic probe to test that chip.  
Someone smarter than me please chime in.
Daniel

Quoted from Atomicboy

hmm used the diode tester on my mm, 7408 appears to be good.  Could the small transistor on the left hole kicker be the issue causing overvoltage in the chip, causing the ball release coil to be permanently on?  I wouldn’t think that would be the cause...

I checked, and there a bunch of header pins that are cracked and could use new solder.  Again, I wouldn’t think this would be the immediate cause either, as a non-connecting pin would not cause the coil to be “on” would it?  That would cut the circuit, where the bad transistor would short it, right?

Unless the diode setting test for chips is not foolproof, it would appear the only issue found is the small 2N4401 at Q20.  It is still suspect though that the only two issues known at the present (left hole kicker, ball release) are both on the same chip...

I guess from here my only options are to replace the Q20, re-flow the header pins, and see from there, oui oui?

Aaron

Hey, if "you're no expert", than I'd be the town idiot, comparatively speaking

I just went by:

Quoted Text

Testing Chips.
The DMM's diode test mode can also be used to check most logic chips. It's best to test chips out of circuit, but frankly this just isn't possible most of the time.

To test chips, the ground leg of the chip in question will need to be known (that's why we went through the "short course on logic chips" above). Then put the RED lead of the DMM on this ground leg. Yes I know, it sounds weird. "Why the RED lead on the ground leg? Isn't that backwards?" Backwards or not, that's how to do it. With the red lead on the ground pin, check all the other pins (except for VCC, which is the chip power pin) with the black lead of the DMM. Again .4 to .6 volts should be seen for each leg. If a different value is seen, chances are the chip is bad. The biggest indicator of a bad chip would be a value less than .2 (probably a short).

In those Williams machines, it is almost worthless to attempt any troubleshooting
prior to having replaced and/or reflowed the 40-pin MPU-driver connector header/pins.

Also, those darn IC sockets (incl. for EPROMs) are often flaky and intermittent,
causing all kinds of intermittent freeze and coil activation/fuse blowing.

I usually replace those using single-line machined pin sockets prior to going further.

Good luck !
- Sylvain.

I read about that too, do you only replace the female side, and re-flow any male pins that are broken, or replace female and male?