solenoid board woes....help needed

[Sinbad79]

Ok guys, Sat morning update...

With respect to the SDB, i have replaced the resistors and diodes corresponding to the bad transistors. The old diodes and resistors all checked out ok...replaced them anyway.

This morning i pulled out (desoldered) all the coils from the playfield, removed diodes, checked coil resistance and diode test, all parts check out OK. Replaced the diodes anyway. Knocked coil was fine, i wonder if the coils have been replaced, they look half decent....???

So this now leaves two possible options
1. Bad wiring, poor pin connections or a short somewhere, or
2. A bad Solenoid Driver Board.

I have a feeling its the SDB, i am tempted to swap in the rottendog and chance it....

Thoughts?

[Boots]

Ok guys, Sat morning update...

With respect to the SDB, i have replaced the resistors and diodes corresponding to the bad transistors. The old diodes and resistors all checked out ok...replaced them anyway.

This morning i pulled out (desoldered) all the coils from the playfield, removed diodes, checked coil resistance and diode test, all parts check out OK. Replaced the diodes anyway. Knocked coil was fine, i wonder if the coils have been replaced, they look half decent....???

So this now leaves two possible options
1. Bad wiring, poor pin connections or a short somewhere, or
2. A bad Solenoid Driver Board.

I have a feeling its the SDB, i am tempted to swap in the rottendog and chance it....

Thoughts?

Find the problem before cooking another board

[Sinbad79]

Thats very insightful... what if it is the board?

Ive verified a handful of wires to pinouts at the connectors according to the schematic and all seems to check out fine... i'll keep digging

[Ballywannabe]

It is simple to see if it is the board - connect J3 only on the SDB.  This means there is NO connection between the playfield and the board, so if it blows the transistors, you know it is the board.  The small target dropping coils are notorious for shorting, so check that closely.

[Sinbad79]

It is simple to see if it is the board - connect J3 only on the SDB.  This means there is NO connection between the playfield and the board, so if it blows the transistors, you know it is the board.  The small target dropping coils are notorious for shorting, so check that closely.

Thanks Bally, did that after inserting Q3 only powered up, powered off then tested transistor....all Good!
So i connected remaining connectors, powered up and no locked on coils.

I ended up changing over the U2 IC on the SDB last night, so this has potentially fixed the issue... i'll keep working through later tonight

A side note - no sound is audible, another dead board??? will see...

[Sinbad79]

Well, success!!
Turns out U2 was at fault all along, no locked on coils and they all fire perfectly. Thankyou all for your guidance so far.

The remaining issues are...
1. Lockout solenoid not working
2. No sound
3. Cant start a credit

[Ballywannabe]

Excellent - as I said I have never seen U2 go bad, but it looks like that board has had a hard time

Your next questions:
1. who cares!  Check the transistor on the SDB, check coil is not burnt out/broken wires.
2.The connecting cables are often broken - check for continuity. Probably worth getting a replacement off Ebay or making up your own. Check the cables are connected properly - pin 1 to pin 1, no gaps between the two separate cables. Check the header pins on the MPU and the sound board.  Check voltages are all at the test points.  Very rare for these boards to go bad, so check the other things first.
3. Can't get a credit up? go into switch test and see if the coin switches are registering, if not try reaseating the switch connectors on the CPU (Right hand ones).  Credit button does not register?  go through the same process.

[Boots]

Well, success!!
Turns out U2 was at fault all along, no locked on coils and they all fire perfectly. Thankyou all for your guidance so far.

The remaining issues are...
1. Lockout solenoid not working
2. No sound
3. Cant start a credit

The connector near the coin door may not be seated properly or is corroded

Check the connectors on the top of the MPU the header pins probably need re-soldering these often fail.

[studley67]

he has put a new alteck in criss

[beaky]

 
I would if you can, repair the boards in question and test in another machine.
if the problem still shows up in another machine then there are other problems on your board / boards.
if the boards work fine after you have repaired them in another machine then the fault is in the questioned machine.
process of elimination !!

[Sinbad79]

Beaky
The credit and start signals go to the MPU connector J3, pins 10,11 and 14. which for me is a new Alltek board. Nothing to do with the repaired driver board as far as i can tell.

I'll just need to work through it

[Ballywannabe]

Double check you have the Altek switches and jumpers set correctly for Galaxy.  Also check for continuity between the switches and the board connector - as pointed out above the wires go through a connector which can occasionally cause problems.

[Sinbad79]

This has me fked, wires make good continuity, pinouts correct etc still no love...

What function is the relay on the SDB responsible for?

[studley67]

flipper power

[Ballywannabe]

Can you get the machine into switch test mode?  If so, are the switches registering in switch test?  Have you tried jumping the appropriate pins on the MPU without the connector on?  Did you check to make sure the Altek is set for the right game, including the 2 jumpers?  Have you tried "clearing" the Altek (see the instructions, but unlikely to be the cause).

cheers
Ian