Alright, so last summer my father picked up a non-working Sharpshooter pin with the intention of working on it as a winter project. Since I am, for all intensive purposes, his pinball tech that means it also became my winter project. Due to a million unforseen issues last night was the first time I got to stop by his place for us to take a look at things. When we picked it up the MPU-2 pcb had some serious battery acid damage so I recently picked up a nice replacement pcb for him from a KLOVer. I was following a walkthrough on testing this game I found online (can't recall the website right off hand as it's bookmarked at his house). So, here's what we found...
Started off the night with everything unplugged from the power supply pcb. Got the correct readings at all of the test points and on the filter cap although I believe the filter cap may need to be replaced as I assume it is the original.
Plugged in the MPU-2 pcb to just the J1 connector. Tested the points T1, T2, and pin 3 on J1 (I believe they are titled T1 and T2) and all looked right on. Pin 3 on J1 was just shy of 30V but the manual and the repair site we were referencing both said it should read at 24V +- 6V.
When we powered the game on fully hooked up the first time we got the start-up static then a bit of a song. I should mention that the new MPU-2 pcb I received had Coney Island roms on the MPU-2 but on impd it says these are the same rom files as Sharpshooter so I left these in for the first power-up. The dips were set on freeplay so I hit the start button and got about 10 seconds of a song then nothing. This song replayed each time I hit the start button. I believe I got 1 LED flash that first time.
I checked a couple other test points to see if power was getting elsewhere on the MPU-2 and SDU pcbs. It was. I powerded down to swap in the 3 Sharpshooter roms and powered back up. This time I got the start-up static but no song and nothing happened when I hit the start button. No LED flashes. The only thing that happened was a light on the upper left side of the playfield blinked on and off repeatedly.
Reading the testing walkthroughs the next steps I saw were that I had to test the reset spikes (or something like that) at different points on the MPU-2 pcb. I believe it was on different pins on U17, U10, etc. Honestly, I am unsure of how to do this. Anyone have any pointers? Does this require an oscillator? I did try swapping out the chips at those two points with the ones from the original MPU-2 pcb but there was no change.
At one point when I powered the game back up I got nothing. No power at all. No readings on the power supply pcb. I checked the power coming into the game at the molex connection as well as at the switch and everything was fine. Checked the power at the bottom of the main fuse and got 30V and at the top I got nothing. So I replaced the fuse and the power was going through but still no activity in the game. So a couple possibilities as I see it...
1) The big filter cap needs to be replaced.
2) The bridge rectifiers need to be replaced.
3) God only knows......
So, this is where we sit. I'm hoping to be able to make a weekly stop at his place to work on this game but I would like to have any pointers going into my next tech session if at all possible. So here are my questions...
1) Where would you recommend I go from here?
2) Where can this big filter cap (10,000 - 15,000 mdf 16V) be purchased?
3) Where would the best place be to pick up some new bridge rectifiers (25A 200V)?
4) How do I do these "reset spike" (or whatever they're called) readings on the MPU-2 pcb?
5) Where would you recommend I go from here?
I'm not completely lost with this game, I just know that I don't have a ton of knowledge on pins and worry that I'm missing something completely obvious. So, thank you in advance for any help you can offer.
On a lighter note, I love working on his T2 pin. We just ordered flipper rebuild kits from marcospecialties and I'm looking forward to installing those.
Started off the night with everything unplugged from the power supply pcb. Got the correct readings at all of the test points and on the filter cap although I believe the filter cap may need to be replaced as I assume it is the original.
Plugged in the MPU-2 pcb to just the J1 connector. Tested the points T1, T2, and pin 3 on J1 (I believe they are titled T1 and T2) and all looked right on. Pin 3 on J1 was just shy of 30V but the manual and the repair site we were referencing both said it should read at 24V +- 6V.
When we powered the game on fully hooked up the first time we got the start-up static then a bit of a song. I should mention that the new MPU-2 pcb I received had Coney Island roms on the MPU-2 but on impd it says these are the same rom files as Sharpshooter so I left these in for the first power-up. The dips were set on freeplay so I hit the start button and got about 10 seconds of a song then nothing. This song replayed each time I hit the start button. I believe I got 1 LED flash that first time.
I checked a couple other test points to see if power was getting elsewhere on the MPU-2 and SDU pcbs. It was. I powerded down to swap in the 3 Sharpshooter roms and powered back up. This time I got the start-up static but no song and nothing happened when I hit the start button. No LED flashes. The only thing that happened was a light on the upper left side of the playfield blinked on and off repeatedly.
Reading the testing walkthroughs the next steps I saw were that I had to test the reset spikes (or something like that) at different points on the MPU-2 pcb. I believe it was on different pins on U17, U10, etc. Honestly, I am unsure of how to do this. Anyone have any pointers? Does this require an oscillator? I did try swapping out the chips at those two points with the ones from the original MPU-2 pcb but there was no change.
At one point when I powered the game back up I got nothing. No power at all. No readings on the power supply pcb. I checked the power coming into the game at the molex connection as well as at the switch and everything was fine. Checked the power at the bottom of the main fuse and got 30V and at the top I got nothing. So I replaced the fuse and the power was going through but still no activity in the game. So a couple possibilities as I see it...
1) The big filter cap needs to be replaced.
2) The bridge rectifiers need to be replaced.
3) God only knows......
So, this is where we sit. I'm hoping to be able to make a weekly stop at his place to work on this game but I would like to have any pointers going into my next tech session if at all possible. So here are my questions...
1) Where would you recommend I go from here?
2) Where can this big filter cap (10,000 - 15,000 mdf 16V) be purchased?
3) Where would the best place be to pick up some new bridge rectifiers (25A 200V)?
4) How do I do these "reset spike" (or whatever they're called) readings on the MPU-2 pcb?
5) Where would you recommend I go from here?
I'm not completely lost with this game, I just know that I don't have a ton of knowledge on pins and worry that I'm missing something completely obvious. So, thank you in advance for any help you can offer.
On a lighter note, I love working on his T2 pin. We just ordered flipper rebuild kits from marcospecialties and I'm looking forward to installing those.
