Asteroids Deluxe - trying to figure out problem

pinballj

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So I thought I would get my asteroids deluxe cocktail going again. I have recapped both the cpu board, and the power supply. I have upgraded the roms to version 2. The game does enter Self Test without a problem, and just gives the little chirp indicating all is well. The test pattern looks great, you can see the ships, and the bonus score, etc. Pressing each button makes a tone as well.

When I switch over to Game Mode though (test switch off), it doesn't do anything. No sound, no video, just the player 1 credit switch staying lit.

Anyone had this issue before? Thoughts on where I can start looking?
 
After going back in the house last night, I thought I would study a little on the schematic. My next steps tonight is to check to see if the game constantly resets, and then go backwards from there..checking the clock signals from the various counters (NMI and program) to make sure they are good. Just seems odd that the game seems to behave fine in test mode, but doesn't do anything out of test mode.

-Jeremy
 
Well if you aren't getting any eprom errors in test mode, and no beeps for memory faults. Then test mode has gone as far as it can.

Make sure you are in free play, or try to coin up the machine, it may be waiting for coin input before blinking the P1 P2 lights.

If it coins up try playing blind.

If it plays blind start looking at the analog out section

If it doesn't then you need to start looking at isolating the Vector state machine to see if you can get it to play blind to determine if the problem is in the VSM or Program
 
Thanks for advice! So, dumb question, but since the test mode does show the diagonal test pattern, etc..can it still be in the VSM section ? I tried coining up last night, but didn't get a blink at all (no change in sound either, and no display either).


Well if you aren't getting any eprom errors in test mode, and no beeps for memory faults. Then test mode has gone as far as it can.

Make sure you are in free play, or try to coin up the machine, it may be waiting for coin input before blinking the P1 P2 lights.

If it coins up try playing blind.

If it plays blind start looking at the analog out section

If it doesn't then you need to start looking at isolating the Vector state machine to see if you can get it to play blind to determine if the problem is in the VSM or Program
 
Thanks for advice! So, dumb question, but since the test mode does show the diagonal test pattern, etc..can it still be in the VSM section ? I tried coining up last night, but didn't get a blink at all (no change in sound either, and no display either).

Yes, it can be the VSM. Test mode doesn't use the VSM to draw.
 
I have a board doing this exact thing. Haven't had a chance to work through it more, but yeah, it's very likely the issue is in the VSM.

I haven't done this myself (I will soon!), but lifting pin 1 of the 7442 IC @L5 should remove the VSM from the equation so you can verify that it is in fact the issue.
 
Update on the debugging

Haven't got it fixed yet, but did narrow down that it is the program side of things and not the VSM side by lifting pin 1 of L5. The reset is still clocking away. I rechecked the ROMS, and replaced the remaining 2 ram chips that I haven't done already (so now all ram has been replaced). Game still boots up fine in test mode when I put pin 1 of L5 back in.

I replaced the 74ls245's and then thought I would replace B1 and C1 even though they looked ok on the scope.

Not exactly sure what I will check next. Seems that everything I have thought could the culpit, I checked!
 
Update on Asteroids Deluxe repair

I borrowed a working Asteroids Deluxe board which helped a lot with diagnosing mine! Still not fixed yet, but farther. I thought I would share my progress though.

Problem: Test Mode worked fine, Shows no issues (buttons work, screen looks correct, ram/rom is fine). Game Mode constantly resets.

Resolution: Disabled DGAO, and determined it was the program side that was causing the reset. Took a rom set from the working asteroids board and put it in to my board, and the resetting stopped! Comparing the roms, it turns out one of the roms had an incompatible version with the others (All but one were Version 1, the other was Version 2).


I since then re-enabled DGAO, and the game still does fine in test mode, but now in game mode it is giving beeps that says M3 is bad. Oddly enough, if you take out the Rams in order, the beeps for the missing ram is given (including if you remove P3, M3 doesn't give the beep, which I thought it would??). My guess is that the problem must reside in the chip select circuitry. I have some replacement ICs on order, which once they come in, I am going to give that a shot.
 
Closer now!

Problem: Game mode it is giving beeps that says M3 is bad. Oddly enough, if you take out the Rams in order, the beeps for the missing ram is given (including if you remove P3, M3 doesn't give the beep, which I thought it would??). My guess is that the problem must reside in the chip select circuitry. I have some replacement ICs on order, which once they come in, I am going to give that a shot.

Resolution: J2 (74LS157) pin 4 was always staying low on the oscilloscope. Replaced J2, and now game starts up.


So the next problem is that the game pretty much immediately resets. I already replaced the blue cap on the power supply, and the board has been recapped. Got to be something else causing the reset.
 
So I cleaned the edge connector, and now it plays for awhile and then resets. Checking the voltage at the board it is at 5.02 volts. I noticed the "good" board having the same problem after I let it run for awhile. So I am pretty sure this is a A/R board issue. I didn't recap it yet (thought it was fine). Looking at the caps, there is one that looks a little suspicious.

Guess it is time for a Bob Roberts order!!
 
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