Hi All,
I have finally got around to posting something on the site.
I have been a member for over 2 years but not posted anything yet.
I had a mate call me about 18 months ago and ask if I knew anyone who could look at a pinball he had picked up.
Having worked in the electronics field for the past 20 odd years, I said I would give it a go.
Anyway he dropped the machine off and I said I would have a look.
The machine was a Bally Paragon. I started my search and found all of the manuals etc required.
I have known Mike at Homepin for many years so thought if I get stuck, I could always call on him as I knew he had a lot of experience with these machines.
The machine looked to be in pretty poor condition with the cabinet very faded and the backglass screen print was coming off the glass.
The playfield was also in very poor condition with wear marks all over place. All of the inserts have also sunken. Some with a 1mm lip in places.
Anyway After finally getting around to looking at it, I discovered quite a few problems with the machine. There was the usual problem with corrosion on the MPU, but it had been left for so long that there was also corrosion on every other board as well.
I thought I could fix the MPU and started to remove components to clean under them, but soon discovered that as soon as I touched some of the pads with a soldering iron, the pad just disintegrated.
I spoke to Mike about it and he told me it was a common problem and I should try and find a replacement on ebay or look at the new boards like the Altek or Rottendog. I spoke with the guy who owns the machine and he didn’t want to spend too much money if he could avoid it, so that ruled out the new boards.
Talking with Mike some more, he floated the idea of redesigning the MPU and selling the bare board.
So off I went. I got hold of the software Mike uses to draw pcbs and started drawing the MPU. I soon discovered there was far more to it than I first thought.
Anyway after many many nights and questions from my wife about what I was doing, I finally had something that looked a little like an MPU.
This is an early shot of the board as it was starting to take shape.
At first, All I did was copy the original board but Mike had the idea of making it more versatile by allowing the use of other parts such as the 6802 etc etc.
We got together and redesigned a few areas of the board and I left it with him to do the final checking and tweaking.
In the mean time, Mike had a couple of old MPU boards he had picked up but needed work so I got hold of one of them and started the repair work. Managed to get it working and put it into the machine.
Before turning it on, I also reworked the power supply and replaced caps on the solenoid driver board.
7 flashed later I found no sound, 3 faulty displays and only the knocker solenoid working.
Removed the sound board and replaced all caps and couple of the really badly corroded ICs including the PROM I got from Skybeaux
While I was doing this, Mike had finished the MPU layout and organised for the boards to be manufactured in China and he also sourced all of the parts to assemble the complete boards.
Over Easter we assembled 2 of the boards in different configurations and crossed our fingers. We started with the 6800 version and ......nothing, no flashes or flicks, nothing.
Anyway we started checking and finally found that during the addition of the 6802 option, I had left out an earth track on one of the pins. A quick jumper and hold our breath again.
1..2..3..4..5..6..7.. Flashes woohoo! It works. Connect a display and yep it works as well. Things are looking good.
A bit more testing then on to the 6802 version, 1..2..3..4..5..6..7.. flashes straight away, perfect!
Pretty happy with only 1 small mod required on the whole board.
Mike has a thread going already here;
http://aussiepinball.com/index.php?topic=5733.0and here
http://aussiepinball.com/index.php?topic=6398.0Returned home with my brand new MPU and plugged it into the machine,
7 flashes and all is working well.
Found the playfield fuse blown, replaced, so now I have the solenoids working.
The inline drop targets are a bit sluggish so they will need a rebuild,
Might also have to look for another playfield.
I will strip it, clean it and see what we can do. I have seen the clear stickers you place over the inserts to build them up again but not sure I want to go down that path.
This photo makes it look a lot better than it is.
Anyway I will keep the updates coming as it progresses.
Peter
