Have achieved a bit over the last week or so. Had another forum member over last weekend @pocketmoney who is pretty cluey in this sort of stuff, so he gave me a few more tips. One issue that was causing drama was the armature for the Merlin kickout hole rubbing on the Mantis protector, so we raided the auto ball launch from a Dr Who project in the shed and used it - these are much better as they have a narrower diameter shaft at the top, so the few mm less was all it needed for clearance. I also trimmed the Mantis protector down a bit on the top edge with a dremel as it was sitting a bit proud of the playfield.
I drilled out and tapped the last of the hex posts - a few that have male threads on both ends were made by cutting to length, then drilling and tapping the end without a thread, then using an old post thread to put in the hole that was just tapped. Loctite this in, and cut off and make sure the thread is still good.
I then started wiring. A lot of people say the wiring harness is a nightmare, but since i've started it, really its fairly straight forward (now this will come back to haunt me!). The GI for the playfield uses three zones (from the manual) top, middle and lower, so i just grouped equal numbers of GI holders and strung them together - being AC, you don't need to worry about polarity or diodes, so its pretty quick. The NBA FB harness had plenty of GI wire in it, and i ended up with some left over, plus a heap of Green and Green/White as MM doesn't use that string on the playfield.
Then i started wiring the lamp matrix - this is a little more complex but still not too bad, as long as you have good sidecutters, wire strippers, soldering iron, heatshrink, 0.156 crimpers and patience!! I started by doing the lamp colunns (yellow). First thing is get the manual out and look where each of the lamps are in that column, and daisy chain them together
I am not really following the original wiring path, just where i reckon it makes sense and is best use of wire - i've done all 8 columns and 4 rows, and not run short yet. Here is a pic of the length of wire in one of the lamp rows (red), and that is still connected to the boards and looped up under the playfield
You can't really test until you've done all the columns, then i test each row as i go. Had an issue in the first row, where two lamps were going when there should have only been one. Triple checked all my wiring and connections, and couldn't work it out until i checked the board - this was a new boards where a diode had been installed backwards from the factory (d2)
So its all looking like a bit of a rats nest now, but easiest is to attack it one bit at a time, with all the wires you don't need hanging out of the machine out of the road
One thing you need to be careful of is working out where the wire goes on the boards - having a machine to copy off here would be easy and you wouldn't have to think, but as long as you check each time for diode orientation and lamp position, it should be right. Also, with the single bayonet lamp holders in the matrix, you need to ensure that they have a diode and it is oriented correctly.
I'm actually finding this part quite enjoyable and relaxing, and initially thought it might be one of the worst parts of the conversion.
