These b*stards hate me - they REALLY hate me !

[Strangeways]

If the globes you replaced are near switches in that column, then you may have shorted the switch - very common, and it will be the ULN2803A chip. But the location of the globe socket will prove the theory.

[Wotto]

Quick way to check if it's the chip wotto.  While its in switch test remove the plugs at the bottom of the cpu

OK

So - to understand properly, I run a "Switch Edge" Test with the connector removed for the switch columns  - yes?
If yes - what 'result should /shouldnt I get ?

Nino - As well as the flashers I also replaced 2 dead Gi globes, one was under the left sling ( so right by the sling switch - which is part of column 4  )

[Ant68]

Have you remove the lamps you put in , to see if the issue goes away ?

[Wotto]

Have you remove the lamps you put in , to see if the issue goes away ?

Oh – sorry forgot – YES I have done that also and it made no difference – fault still exists

[ddstoys]

It you remove the plug and the row / column is still stuck on the board is at fault if the row becomes unstuck the fault is on the playfield

[Steevsee]

Quick way to check if it's the chip wotto.  While its in switch test remove the plugs at the bottom of the cpu

OK

So - to understand properly, I run a "Switch Edge" Test with the connector removed for the switch columns  - yes?
If yes - what 'result should /shouldnt I get ?

Hi Wotto.

You need to remove the connectors for both the rows and columns, then use a jumper wire to simulate triggering the switches.
If you're not sure how to do this check Clay's WPC repair guide. (PM me if you don't have access to a copy)

You should be able to trigger the column 4 switches this way, if not then you have a bad U20 for sure.

[Wotto]

Thanks STeevsee and all others for the input so far...

OK - I ran the tests as page 70 / 71 from the Clay Guide ( with the test lead and diode )
In the Switch Levels Test mode I got following results from pins on J207-  1 to 3 all good, NOTHING on 4,  5 good , 6,7 ( no 8 ) and 9 all blank like 4 

When I reversed the lead and diode as per page 71 all tested fine on J209.

Any new thoughts on this - ya reckon I did this right?
did I even do the correct test 

[swinks]

left field and a stab in the dark, couldn't be something similar to what Dave suffered and solved on his creech

http://aussiepinball.com/index.php?topic=8057.msg106080#msg106080

[Steevsee]

Thanks STeevsee and all others for the input so far...
...did I even do the correct test 

Sounds like the right test even though it's on a different page in my copy of the guide.

Columns 7 and 8 (pins 7 and 9) are not used in CFTBL(not sure why 6 not working?) but column 4 should certainly have registered if U20 was ok.

Hate to say it Wotto, but it looks like it's time to replace U20.

[Strangeways]

Thanks STeevsee and all others for the input so far...
...did I even do the correct test 

Sounds like the right test even though it's on a different page in my copy of the guide.

Columns 7 and 8 (pins 7 and 9) are not used in CFTBL(not sure why 6 not working?) but column 4 should certainly have registered if U20 was ok.

Hate to say it Wotto, but it looks like it's time to replace U20.

I agree. Might be time to replace U20 and I'm sure the problem will be fixed.

[Wotto]

 

[Wotto]

BOY O BOY - wish me luck 

[Steevsee]

Good luck mate.

By far, the hardest part is getting the old chip out without damaging the board.

Unless you have a very good desoldering station, I find it's much esier to cut the old chip out with a dremel and VERY steady hand. Cut close to the chip body and you can then easily desolder and remove the pins one by one.

Obviously you have to go slowly and carefully when using any tool around your precious boards.

[goodolddays]

Good luck mate.

By far, the hardest part is getting the old chip out without damaging the board.

Unless you have a very good desoldering station, I find it's much esier to cut the old chip out with a dremel and VERY steady hand. Cut close to the chip body and you can then easily desolder and remove the pins one by one.

Obviously you have to go slowly and carefully when using any tool around your precious boards.

Another way I have used before (not owning a dremel) is cut the legs off with side cutters.

[Retropin]

mmmm yes....small electronic side cutters from Jaycar... that pic of a Dremel over a chip on a PCB gives me the squirlies