I went back to the power supply board today for two reasons; I still had that little POWER FAIL circuit to fix and I had trouble finding the reason why my controlled playfield lights weren’t lighting up. So I found that the 5V was missing from CN2.
After some testing I found that it was the fuse and fuseholder were oxidised. Some cleaning took care of that and now the 5V is back.
It occured to me that now that this 5V was back, the POWER FAIL circuit had to be revisited, and low and behold, the POWER FAIL signal is gone. So the circuit wasn’t failing, I had a missing voltage and had completely missed it. DOH! /facepalm
I reconnected the POWER FAIL signal on the CN9 connector on the CPU board and everything still boots up 🙂
After that was all over with, I started disassembling the playfield, documenting everything with a lot of photo’s since I want to be able to put it all back together again too…
Once I removed everything from the top of the playfield, I flipped it over and got to work on the top drop target bank.
I removed the broken drop target, replaced it with the one I got from David from zaccaria-pinball.com (see my links) and flipped the playfield over again.
So with that done, I started cleaning. I haven’t done a lot yet, but here’s a picture for you to see how much difference it makes already.
And notice the working lights, what a big difference 5V makes 🙂
Although I’m in Sweden this week and the next, I haven’t forgotten about my pinball machine…
I’ve been franticly searching the Internet looking for those elusive parts that I so dearly need to get the machine back to pristine condition and I think I’ve done it.
From the Multigame site (see the links section) I’ve ordered a rubber set, a new pinball, a doorlock and some more small parts, together with some cleaning materials.
David, from www.zaccaria-pinball.com has sold me a spare “H” target and a replica door sticker and they are on the way.
And then the two memory chips… The 6514J-0 was relatively easy to find. A search on ebay found three vendors in the US, so I ordered one and it’s on the way. The 2114L was an alltogether different story. No hits on ebay or anywhere else.
It was even hard to find the correct datasheets for this memory chip, but after going through dozens of datasheets, I finally found the correct one. I’ve put it up here in the datasheets section on the right, so you don’t have to go through that experience yourself.
I found out that Texas Instruments made the same memory at different speeds, after looking up those datasheets and checking the TI speeds with the ones from Intersil, I started looking for a TMS2114L-45NL. Again, no luck 🙁
Then I noticed that the top of the Texas Instruments datasheets state “Previously Called TMS40L45”, so I searched for a TMS40L45-45NL on ebay and BINGO, there’s one on the way 🙂
According to the datasheets it should work, but I guess you never know until you put it in the CPU board and run the test.
Since I spend a lot of time looking for datasheets, I’ve decided to put them up here for anyone else that might be restoring a similar machine…