Diagnosing a Star Trip cocktail

[Rabies]

Hi. I posted my first post over in Open Discussion: http://www.gameplanpinball.com/forum/index.php/topic,118.0.html

Now I'm here to hopefully get some assistance in working out what's wrong with this Star Trip.

Basic summary: Got it from someone who got it non-working from someone else. Claimed he didn't know much about electronics, bought an MPU-2 off Ebay, plugged it in, didn't work. And that's that. Now it's my problem! 

First thing I did was replace a missing fuse and some badly rated fuses. Second thing was attempting to check voltages (refer to my other thread for more info).

The MPU-2 has SharpShooter ROMs, and shows NO LED flashes at all. Now, it might not be getting the voltage it needs, but I've discovered another problem, it has some strange modifications:

On the component side, it has jumpering and cut trace that is consistent with the 2716 mod mentioned here: http://www.pinrepair.com/gp/#roms And it has the cut trace for 2716 on the solder side.

So far so good? No, it has jumpering on the solder side that partly matches the 2732 mod!



Can anyone make sense of that? Is it a mod for yet another kind of EPROM?


I'd also like to know if it's necessary to get the blower working or replaced. Mine's rusty, so I just unplugged it.

[goose]

Look at:
http://www.pinrepair.com/gp/

Most everything you need at one place for Game Plan pin repair.

Goose

[Rabies]

Yeah, same web page I posted above.

[goose]

Sorry, I missed that.

Well, it probably was done by a confused person.  What I would do is to remove the mods for the 2732, and install the mods for the 2716.   I went pin for pin using the data sheets for both devices so I understood what was being done.  Buy the 2716 PROMs for Star Trip (John Wart sells them) and verify that your voltages are correct and try again.

The Bottom line is don't assume that a modification that was done is correct, Always verify it.

Mike

[Rabies]

I should have come back and updated this thread a couple weeks ago. (I have threads going on 3 different forums...)

Basically, I did what you suggest. I verified every little modification, etc against Marvin's repair page. It turns out the board once had some other mods that were then REVERSED, and in its current state it is set up for 2716.

I bought new EPROMS, installed them.

Pulled the power block out because it was FILTHY, and cleaned it completely off.

Next step is cleaning out the interior, cleaning connectors on all boards, putting the power block back in and testing voltages. Then I'll hook everything up and cross my fingers.

[Rabies]

Diagnosis & Repair update :

-ditched Ontario hydro iso
-installed new fuses
-pulled all boards
-cleaned inside
-cleaned dirt off power block
-installed new ROMs on MPU
-visual inspection of MPU (checks out)
-visual inspection of other boards
-cleaned all connection pins on boards
-replaced capacitor on power supply

-reinstalled all boards
-attempted to test power supply (but instructions on PinRepair don't match since they use an upright pin power supply which has a different layout)
-reconnected all boards
-On power up, everything seems same as it was before:

Some lamps are lit, I hear something click once but can't figure out which solenoid it would be. MPU LED not lit, does not flash. Score displays are blank. Test switch does nothing. Reset switch on MPU does nothing.

Also: ball outhole solenoid is burning up. I think it's the last solenoid in the series, which reminds me of similar problem some one described here recently.

I'm stumped.

[BriMc]

Hi Rabies,

First off stop trying to get the machine to fire up right off the bat, it is not going to happen. Disconnect all the connectors from the mpu board. If you look at marvins site it tells you what voltages and amps the fuses are, I would use the fuses to start off as test points. Problem one is you do not know what conditions the other boards are in so you could wipe out the mpu every time you power up the machine. Problem two is you have not checked the voltages of the power supply so you could be cooking  the mpu. Get the power supply correct first and then head towards fixing the mpu. The mpu will fire up without anything else connected to it but the power supply.

[Rabies]

Makes sense, but Marvin's page refers to the upright power supply which has a different layout than the cocktail and has no marked test points.
 

[BriMc]

Hi,

You are absolutly correct, but if you look at the power supply section there is a picture of your power supply and the voltages are marked on it. I am he most impatient person when it comes to repairing gameplan pins. I have learned over the past ten years of repairing gameplan pins one step at a time. I can not count the number of times I have blown up a perfectly good MPU board because I was in a rush and did not follow that rule.  As a matter of fact I have done it in the past few months You have the basics, power supply first and then mpu.
-Brian