Pinball 2000 power \ driver board fault fiding & mistakes in schematics

[beaky]

Hi Guys,
Just a quick note regarding the pinball 2000 schematics.
I have found that on quite a few of the pinouts on the schematics do not match the actual board layout.
I will give a basic list on these in the near future.
this has been making it a night mare to beep out all the tracks for the data lines and so on a pin 2000 power driver board.  

[Marty Machine]

Nothing quite SUX like an incorrect schematic, damn they can cost you days of labour because thigns don't match up, then you're led to tracing tracks.....yuk!!!

...of course if you get rid of your pin2k machine, then the problem is gone ;-) 

MM.

[beaky]

Nothing quite SUX like an incorrect schematic, damn they can cost you days of labour because thigns don't match up, then you're led to tracing tracks.....yuk!!!

...of course if you get rid of your pin2k machine, then the problem is gone ;-)  

MM.

It's not mine Marty. I have been working on this one board that is a shocker, not only has it had dead I.C.s it also had one that was changing the voltage on the data lines, the warmer it got the higher the voltage on the data lines got (between 2 & 4.5 volts  )and when it was cooled down the data line voltage dropped. Not that the I.C got hot to touch or anything.
It made for some interesting intermittent faults, such as when the coin door was open for a while the switch matrix would register it as closed and enabled all the so called high voltage circuits. then when in attract mode it would randomly start the game without pressing the start button. The strangest thing was that the faulty chip was one of the ones that monitor the fuse circuits and had nothing to do with the dedicated switches.(the start button and door switch are on dedicated switch inputs for those of you who didn't know.)
  

[Marty Machine]

one word ......... NASTY !!!!!!

[Pintoxicated]

Pitty the poor sucker that owns this machine.   

Thanks Beaky.   

Yes it is my RFM driver board that Beaky is referring to.   

[Marty Machine]

the kind of board that needs calibrating.........................................with a hammer!!!!!!!!!

[beaky]

the kind of board that needs calibrating.........................................with a hammer!!!!!!!!!

It's the type of board that the lm339 is ok but the 74hctxxx that is behind the lm339 is stuffed 
Then I noticed that a lot of the insert lamps are not working, then I notice that one of the led's next to the insert lamp fuse is out. fuse checks out fine & it has the correct voltage on the test point. turns out the led is faulty but of course changing an led won't fix the inserts being out. and there are no faulty transistors for the inserts. I haven't found out yet what is causing the problem. 

[Marty Machine]

I haven't found out yet what is causing the problem. 

The problem is YOU, you're still having a go at it hahahahahahahaha. 

sounds mighty NASTY though....too many variables like that can really ruin someones day.

MM

[Strangeways]

That's why I steer clear of Zaccaria board repairs. The schematics seldom match the board components. Frustrating !

[Pintoxicated]

Sounds like you might to take a break from it for a few days Beaky.

[beaky]

Sounds like you might to take a break from it for a few days Beaky.

Na not just yet. I will give it another go tonight.
At times like these i really wish I had an oscilloscope.
I am getting a signal up to the 74hctxxx when the switches are activated and I know that the when i pull the data lines low with the 74hctxxx chips out the program I am running on the pc I have connected to the parallel port on the driver board shows that the data lines are going low. I know that the 74hctxxx chips are fine for the switch matrix.
So next thing I will check are the I.C.s for the register control.
Then If that is not the problem then I will be checking the I.C.s on the data bus that control the lamp and solenoids.
I know that sounds strange but if the I.C,s that are related to monitoring the fuses can cause a problem with the door switch and the start button then anything is possible on this board.       

[Marty Machine]

Have you monitored the 5v rail on the board while testing? i imagine it's raising up/down too.....
I'd be looking around the onboard regulator oand/or any capacitors and diodes associated with mainly the 5v supply.

I can't see how digital chips have a varying LEVEL of logic, so i'm thinking it's more to do with supply voltage and not logic/chips being faulty.

my 2c ;-)

[beaky]

Have you monitored the 5v rail on the board while testing? i imagine it's raising up/down too.....
I'd be looking around the onboard regulator oand/or any capacitors and diodes associated with mainly the 5v supply.

I can't see how digital chips have a varying LEVEL of logic, so i'm thinking it's more to do with supply voltage and not logic/chips being faulty.

my 2c ;-)

checked all that. constant 5.01 volts
Plus I did the old freeze spray test. freeze spray on I.C. voltage dropped, finger on I.C to warm back up to room temp voltage rose. Replaced I.C. voltage was constant 5 volts & intermittent fault was gone. Before I.C. was changed door switch would close and open for a few minutes on its own then it remain closed even when door was closed (even by disconnected switch).
Replaced I.C. fault was gone even after an hour of running.
Some one else tried to fix this fault by changing the lm339 that relates to the coin door switch and start button.( before pintoxicated owned it)

[beaky]

I managed to use an old amiga computer monitor for a test monitor. It's not good enough to play a game on but it does do the job.
I will need to sit a mirror in front of it so the image is not mirrored.

[Marty Machine]

I managed to use an old amiga computer monitor for a test monitor. It's not good enough to play a game on but it does do the job.
I will need to sit a mirror in front of it so the image is not mirrored.

....or you could swap the Horizontal-Yoke wires on the monitor neck, to do the mirror-flip, or even put the wires thru a switch so you can revert to using the monitor normally for anything else ;-)

MM