Any Bally experts out there? I have some voltage questions 1978 Playboy

[channelmaniac]

You can really only check the clock crystal with an oscilloscope as it generally doesn't swing enough to trigger a logic probe.

Now you can check the clock signal at the CPU with a logic probe.

Checking with a voltmeter really doesn't tell you anything.

[poppo]

Checking with a voltmeter really doesn't tell you anything.

Well, yes and no. Ideally one would have access to a probe or scope. But the test ROM is designed to help you troubleshoot the MPU with minimal test equipment by running a specific loop to check the main CPU and PIAs. If the clock is running, the meter would read about 2.4V on those specific pins. Not a perfect test, but it would be +5v or 0v if it was not running. It could be running to fast or too slow, but typically it's either working or not.

[poppo]

Any updates?

[jbshocks]

Funny you should post this.  My parts came in from big daddy today (they are a little slow) and I have been playing it for the last half hour.  It turns out poppo that U2 on the driver board was the trouble.  I did try U3 first but it was still locked on.  It still needs some tuning up but at least it is playable.  I have not rebuilt the solenoids and I can tell a few need that and I have some lights not working.  Some things that were not working in the first 5 minutes are working now so I figure I will run it a little and then tear into the little issues.    Thanks so much for the help on this. 

[poppo]

Good deal. This is where the self test button helps. Good for finding those stuck switches and cycling the solenoids, testing the displays etc.

As for the bulbs, the lamp diver SCRs are notorious for going out (for the switched lamps). I hope you bought some of those too.

BTW, if you are thinking about switching to LEDs, they may work well for the general lighting, but may flicker if used for the switched lamps. That is because the switched lamps are being strobed. An incandescent bulb will keep glowing for the very short period of time between the strobes and your eyes will not notice it. However an LED will visibly flicker. This applies to these older Bally machines. It might not be an issue for newer machines.

[jbshocks]

each time I ordered parts I threw on some extra so I have all that.  Also extra diodes, solenoid transistors.  The mane lighting issue is that all of the lights on the left left of the rabbit are out.  I haven't looked at the schematic yet but I am guessing some sort of common is bad.

[jbshocks]

thanks for the tip.  I hope mine are good as these are pricey little jewels.

If you do decide to go that route, you may want to consider getting 7 digit displays and using a modified ROM that let's you go over 1M points. That's what I did with my Space Invaders. IMO it's too easy to get 1M points and then it just rolls over.

The modifed ROM can be found here.
http://www.ipdb.org/machine.cgi?gid=1823

Instructions for the hardware mod are here. You only need one for all of the displays. It's not that hard to do
http://www.pinball4you.ch/okaegi/pro_d7.html

Here is mine.

I have one display that has some slightly messed up numbers which I guess indicates it is on its way out.  I have no idea how long they last after they are a bit screwed up but here is my question.  I understand that you can replace just one display with an LED but could you do the 7 digit mod and only put the 7 digit in player one and leave the originals in all other positions?

[poppo]

I have one display that has some slightly messed up numbers which I guess indicates it is on its way out.  I have no idea how long they last after they are a bit screwed up but here is my question.  I understand that you can replace just one display with an LED but could you do the 7 digit mod and only put the 7 digit in player one and leave the originals in all other positions?

You might try re-flowing the solder joints where the display meets the display board and also the display connector solder joints. I have had that fix a few.

You can put in a 7 digit LED as is. It will work just like the ones in there, except the leftmost digit will never do anything.

If you do the 7 digit mod (which is both software and hardware), it will effect all displays. If you don't know, this is what they do. The software is modified to divide the score by 10 immediately. Then a fake zero is displayed in the right most location making the score look right. For example a score of 1000 is divided by 10 to give you 100. Then add a fake zero to the end and it displays 1000 like it should. So since it would normally only go up to 999,999,  if you divide by 10 and add the fake zero, it will then display up to 9,999,990. Some hardware is also needed to decode the extra bit that was initially not used. But you only need one for all of the displays.

As I recall you got one of those Ultimate MPUs. I don't know if they have incorporated the 7 digit mod ROM into it or not. So it might be a moot issue. Although one could burn a new ROM with the modified code. 

[jbshocks]

thanks for the further explanation

[jbshocks]

poppo,  I have a couple other questions now that the machine has been running for awhile. 

1. I have about 4 GI bulbs that keep burning out.  They typically get a little brighter than the other bulbs for a little while and then burn out.  2 are pop bumpers and 2 are bank bumpers.  Is this common from vibration?

2.  There are 4 roll overs at the top and if you roll over lane 1 or 4 both light go out,  roll over 2 or 3 and both go out.  This is normal.  On the third time of trying to clear these lights when you roll over 2 or 3 light 3 stays on.  You can go over 2 or 3 repeatedly and light 3 will stay on.  Soon as you loose the ball and go to the next ball the light will go out.  I could see the SCR sticking on but it seems strange that it only does it under these specific situations.  Any thoughts?

[poppo]

1. Yeah, it's not uncommon for the bumper bulbs to get bright and then burn out. It is from the vibration. I got tired of the pop bumpers lamps going out, so I put some of the bright 4 LED bulbs in my pop bumpers and the problem was solved.

2. Without seeing how the scoring works, it's hard to say. The one light staying on after the third roll over may be due to a bonus/special indicator.  Does any other lamp come on when they have been rolled over a third time? Maybe the bonus/special lamp is shorted to the 3rd lamp causing it to light up whenever the bonus/special lamp is lit.

[jbshocks]

Thanks,  I think I will take the LED route on at least the troublesome bulbs.  Any source you like for the LEDs?  I will check the bonus light short idea. 

[poppo]

These are the LEDs I used for the pop bumpers. Actually they are 4+1

http://www.marcospecialties.com/control/keywordsearch?SEARCH_STRING=05-44w-41

But they are out of stock.

[jbshocks]

another question.  in attract mode or after pushing the game start button there is a faint hum.  Soon as the ball hits any target the hum will go away.  once you lose the ball the hum is back until you hit another target.  Is that normal?  If not any thoughts?

[poppo]

Is the hum by any chance coming from the speaker? My space invaders had a hum that would come from the speaker. So I connected a +5V regulated wall wart power supply to the sound board (disconnected the normal +5V but used a common ground) and the hum went away. Note: It must be a regulated +5V.

If it's not coming from the speaker, the only other thing I can think of is possibly a drop target solenoid driver that is acting up. When you press the start button, all of the drop targets are reset. It should be a momentary activation of the solenoid, but if one was staying on, it would hum. Not sure why it would stop when you hit another target though.

Here is a picture of my sound board. The two black wires with the arrows are coming from the regulated +5V power supply (the one with red is +) The original +5v is removed and taped off. Click on picture to enlarge.

[jbshocks]

this is from the speaker and it is almost like the last tone of the start up music continuing.  I may try the 5v power.  I did recap the sound board before ever getting the machine up.  I kind of wish I would have done that afterward to make sure that was not the issue.

[poppo]

this is from the speaker ....

Ok. I think it's sort of normal considering how all of the wiring is packed together. I looked at the +5V line with a scope and was very noisy. And that was even with a new MPU, new solenoid driver board, and new lamp driver board.

[jbshocks]

but with the external power yours does not hum?  Do you think shielding the the 5v line with nickel tape or something could help or running a twisted pair with + - 5 lines over to the sound board?

[poppo]

but with the external power yours does not hum? 

Nope, none at all.

I did try using more ground straps and some other things, but it really didn't help. Just too much noise is getting introduced into the 5V line from all the SCR switching and what not going on. You could try putting some different value capacitors across the 5V line (10uf-100uf) where it comes onto the sound board, but I didn't have much luck with that. I then tried the regulated (switcher type) power supply and the hum was gone. 

[jbshocks]

I have a little 5v cell charger that is .7amp output.  Would that be enough or do you think it is to small to run the sound board?

[poppo]

Might work if you keep the volume low. The one I am using is 2 amps.

[poppo]

Any updates?

[jbshocks]

I have been distracted with my silverball mania and haven't found a proper power supply yet.

[jbshocks]

Since I now have a functioning original MPU and known good chips I decided to get really aggressive  with my attempt to get the original playboy board to boot.  I figured what do I have to lose.  So I put the board in the dish washer.  I had heard about doing this but was a little scared.  I gave it a good cleaning in the dish washer with all removable parts gone and  then preheated the oven to 200 and turn it off.  I left the board in the oven for 2 hours.  I got it out and a few areas kind of turned ugly so I guess they probably were not as clean as I thought.  I took the dremel with wire wheel and polished those bad areas and then followed the instructions on that test U6 program  http://home.scarlet.be/~fb054529/bally/ebalmemtest.htm  I am all the way through testing all chips and get all proper flashes.  YEAH!  Sadly since I have to wait another 45 minutes to erase the 2732 U6 in order to write the game program back I can't test in the machine yet.  Even if it won't get the game running it was fun to mess with and I could never have gotten it this far poppo without your help. 

[jbshocks]

I guess testing is done for tonight  the erased eprom failed the blank check.  I tried to write it any and of course it failed.

I couldn't just go to bed so I put the chip back in the uv eraser for 10 minutes and it blank checked.  It wrote with no issue and the board passed bench test.   I put it in the machine and it booted right up.  I played 2 games and rebooted the machine 3-4 times.  It seems to work perfect.