Moving on to Solonoid Driver Board

[deep six]

Thanks Boots

Just a thought, I bought a 3 amp circuit breaker from Jaycar the other day, this machine specifies a 1 amp slo blow under playfield but would the 3 amp circuit breaker soldered on to an old fuse be OK to trouble shoot the mystery coil.
Oh, and good idea on the power board thing, that will make it a lot easier.

Cheers

[Boots]

Hmm not sure
I have only ever done it with a 2a slo

[deep six]

Having fun and games this time around. The RCD unit on our meter box is very touchy and keeps tripping every time I start up Galaxy.
managed to boot the game up and watch as a coil stuck on. Clipped off the power wires to that one and tried again, starting to run out of fuses so tried my 3 amp circuit breaker, booted up machine again and tripped the RCD once more.
Family is starting to get the shits with me as I keep interrupting their tv program.
Thought I would sit back and contemplate for a while. What has got me thinking is why is the coil locking on when it tests out at 11 ohms, must be something in the driver board but the thing is I tested all the transistors and they are within specs. Is there something else I'm missing here??
Maybe I should just go ahead and change the transistors since I have a bag of them here anyway.
Another thing that is weird is the small individual coils on the drop target set test out at around 150 ohms, I know that under 3 ohms is bad but what does it mean when they measure over 150ohms???

Cheers again for all your input

[Boots]

Hmmm
Is the RCD tripping or the circuit breaker?
The RCD shouldn't trip when you turn the machine on, check your earthing on the machine using your multimeter with the power off.
You should find the earth leak before going any further.
You haven't got some wires pinched against the ground plane in the headbox have you?

[Skybeaux]

If the transistors test good but the coil's still locking on then one of the ca3081 pre-driver's may be stuffed.

[Strangeways]

I'd take a step back and start with the basics. Remove J1 and J3 from the Rectifier board. Switch the game on and check each voltage at the test points.

Then add J3 - The game should not be tripping the safety switch

If you have got this far without tripping the RCD, then it will be a coil or something on the Solenoid Driver board. Install J1, and it will trip.

I would remove the connector to the relay mounted on the transformer board. This eliminates one problematic output from the SD board.

You could try to isolate the coil / transistor / CA3081 (as Ken suggested) by removing connectors from the SD board and switching the game on. With all connectors fitted, this is the breakdown of the Transistor outputs by connector on the SD board;

J1

 Lower Right thumper

J2

Left Flipper Button
Right Flipper Button
Coin Lockout
Left Sling
Right Sling
Tp Thumper
DR Target reset
Knocker
Ball Kicker

J5

Saucer
DT Red
DT Blue
Outhole
Lower Left Tumper
DT Yellow
DT Black
GI Illumination Relay


Switch the game off. Remove all connectors (J1, J2 and J5) - switch on. Nothing should happen. Switch off. Add one connector at a time  until it blows the fuse. Then you have isolated the problem to one connector with the culprit being one of the coils or CA3081.

I'd suggest one of the small coils in the drop target assembly is shorted against something or the DT reset coil is the problem. But the GI relay can also cause issues.

[deep six]

Back and forwards this weekend, spent most of today tracing a shorted wire in my Suzuki Vitara, didn't find the short but unplugging the loom and fixed it that way, got transmission fluid all over my nice white T short after crawling under wifes Trans Am trying to fix an oil leak, I think these cars come with factory oil leaks.

Now back to galaxy, put a new fuse in the under playfield holder, didn't trip the RCD this time, pretty sure there is something wrong with the RCD in our fuse box, it seems to trip indiscriminately. no real trigger, the other day it went out when I was half way through a print job which is somewhat annoying.

Anyway, back to galaxy, put a new fuse in, plugged it into mains, carefully watched under playfield to see whats up, it almost seems as if every coil is trying to fire at once, its hard to say as the fuse blows pretty quick but there is definetely multiple coils fireing, and I have already clipped the power wire to two coils.

Might be what Ken said about the CA3081, but at this stage I don't know what that means, quick trip to Pin wiki might be enlightening,

Looking at what Nino says, just trying to get my head around this, isn't the relay on the transformer board just to power the lighting during diagnostics??

Will pull the connectors off at J1, J2 and J5, see if I can find another fuse and work back from there.

Thanks guys, must be frustrating trying to educate me, I really appreciate your efforts.

Cheers

[deep six]

OK

Maybe getting somewhere,  just following Ninos advice, disconnected J1 J2 and J5, found a new fuse for under playfield.
Started machine up and pretty much as I expected, no blown fuse this time.
Powered off, plugged J1 back in, picked this one as it is only controlling one coil.
Checked fuse still OK, powered machine back, up, fuse didn't blow but noticed humming noise and discovered lower right thumper is locked on.

powered off, disconnected J1 from solonoid d board, connected J2,

Powered up, noted several coils firing at once, then the fuse blew.

So I think it is pretty safe to say there is  something amiss in the driver board, where to go from here though??

[Homepin]

Maybe it's time to get someone to look at trhe driver board for you as it seems it will require work that maybe you need help with at this early stage.

[Boots]

Powered up, noted several coils firing at once, then the fuse blew.

So I think it is pretty safe to say there is  something amiss in the driver board, where to go from here though??

Remove the driver board from the machine and follow the Pinball guides on how to check each of your driver board transistors with your multimeter.
You can check the IC's too with your multimeter.

[Strangeways]

Powered up, noted several coils firing at once, then the fuse blew.

So I think it is pretty safe to say there is  something amiss in the driver board, where to go from here though??

Remove the driver board from the machine and follow the Pinball guides on how to check each of your driver board transistors with your multimeter.
You can check the IC's too with your multimeter.

+1

If you are not confident in repairing the board, just send it off the Ken or Andrew to look at.

[deep six]

Just did some tests on the board, the transistors seem OK but possibly some a bit iffy, seem the get a slightly different reading each time I check them but could be just me not holding the probes steady enough.
The diodes are out of the specified range, test about .80 in one direction and .55 in another, all pretty much the same so not sure whats up there.
The U1 chip doesn't look too happy, pin 12 reads .484 and according to my specs should be .1 to .2, pin 13 reads 1.50 and should be .7 to .8
So looks like the chip, (or chips) are bad, no big deal really as the solonoid driver board kit I got comes with new U1, U2, U3 and U4 chips and new sockets.
However would be nice to get someone else to look at this to make sure I'm on the right track and there is no other underlying problem.

[deep six]

OK update time.
Figured this driver board needed some professional help so I contacted Ken (Skybeaux) and arranged to call over at his place so he could chuck the board on his test machine.
Once I arrived with a bundle of parts and a board under one arm we proceeded to hook the board up to kens tester.
Ken was concerned my board might blow his test jig but not half as concerned as I was.

So after quickly flipping the power on and off on the test jig we observed that several coils were firing at once.
Didn't take Ken long to discover that the U1 chip was toasted. Quick as you like Ken fired up the de-soldering station, whips out the old chip, solders in the new socket I brought along, plugs in the new U1 chip and bobs yer uncle.

Run the board on the test jig again and everything is working as the pinball gods intended.

Now right here I have to give Ken a big thumbs up. He welcomed me into his workshop, fixed my problem and didn't even want to charge me for his time.
And to top all this off later in the week when I discovered I had been shortchanged in my HV rebuild kit to the tune of one trim pot, Ken kindly posted me up a new one which I have now fitted.
So what I am trying to get across is that if you are in the Newcastle area and looking for someone honest and reliable to work on your pinny you could definetely put Ken on your list of preffered tech's.

So the galaxy is almost ready to fire up once again. I spent most of saturday re-pinning the Solonoid Driver Board and for good measure I re-pinned the MPU board too.
I repaired the MPU board acid damage and tinned the tracks as per Kens advice.
I fitted a new capacitor battery so I never have to worry about leaking batteries again.
I then set about the task of renewing the connector terminals, this takes a long time and you need a lot of patience and a good crimping tool.
The tool I'm using is a low end Jaycar number, it seems to work OK, I just hope I have done the job right as there are a lot of connections and it would be a real pain to try and track one down should it become loose.

I noted the ribbon cables that go to the MPU board are less than pristine so I am researching where I can get replacements, they look like computer IDE cables but not sure on that. One of the ribbon cables has a jumper wire soldered in so that doesn't pass the (no hack) test.