Asteroids Cocktail Troubles

[csa3d]

I am having troubles getting my asteroids cocktail cabinet up and running, and was hoping someone could help me with the next steps to take.

I've done following repairs thus far:
- Capped the main PCB, the AR-1, and both boards on the G05
- Replaced all fuses on all boards
- Did edge repair on the main PCB
- replaced all pins on the wiring harness
- replaced the AC plug because someone cut off the ground pin

I've ran a self test and I get only 1 low beep, and nothing more. I'm guessing this means it failed on the first RAM. According to the manual, this ram would be in position D2. My PCB appears to have never had a chip installed at this location (see attached image). What do I do from here? If I need to buy chips for the board, should I just buy all RAM/ROM chips ahead of time, assuming that others will be not working as well? Where do I get these from.

I've also run voltage tests on the power block using http://forums.arcade-museum.com/showthread.php?t=121666&highlight=test+power+supply+voltage&page=2 as a guide.


Here's my results:

=====================================
Power Brick
Remove the big 15 pin connector P5

***V***V***
*1***2***3*
*4***5***6*
*7***8***9*
*10**11**12*
*13**14**15*
***********
=====================================

Meter set to 20vdc
Red lead to pins 1, 2, 3
Black lead to pins 4, 5
Reading should be 10.3 vdc (could read high 13vdc as it is unregulated)

reading: 14.15 (high)


Meter set to 200vac
Red lead to pin 6
Black lead to pin 7
Reading should be 36 vac

reading: 37.5 (high)

Meter set to 20vac
Red lead to pin 8
Black lead to pin 9
Reading should be 6.3vac

reading: 7.1 (high)

Meter set to 200vac
Red lead to pin 10
Black lead to Pin 14
Reading should be 80vac

*** No reading: My power supply has no pins in either spacer #10 nor #14 ***

Meter set to 200vac
Red lead to pin 11
Black lead to Pin 13
Reading should be 65vac

reading: 62.9 (low)



=====================================
A/R I
Remove the 9 pin connector P7 (P5 on the power brick must be plugged back in)

__^__^__
*1**2**3*
*4**5**6*
*7**8**9*
*********
=====================================

Meter set to 20vdc
Red lead to pins 5, 6
Black lead to pins 1, 4
Reading should be +5vdc (could be as high as 7 or 8 vdc because there is no load)


reading: 6.3 (high)

Where do I need to adjust anything to tweak these values any?

-csa

EDIT: Link to my restoration thread here: http://forum.arcadecontrols.com/index.php?topic=94356.0

 

[csa3d]

more images...

 

[csa3d]

last of images..

 

[csa3d]

I should also add, that I can hear some ticking/static somewhere in the monitor.. either in the EHT or the around the monitor neck. With lights turned off, the monitor neck has glow.. and I'm unable to see any sparking in the EHT.. so I'm not sure what's going in there. I cannot see any parts on the EHT board which appear burnt or blown since I've replaced them.

I can say that every time I've discharaged the monitor, I have never once heard a zap noise.

Also, when I was cleaning out parts on the monitor, the diode that connects the D904 EHT Rectifier (connects to anode tube) was SUPER sticky. I disconnected it, cleaned it as best I could, then put it back together.

There is a slight "hot" smell that I get after keeping the unit on a while poking my in there for inspection which makes me nervous. Not sure if this is something I should expect from 40 year old electronics or if something bad is going on.

-csa

 

[Arcadenut]

Your voltages don't look that far off. You need to check the voltages at the board.

If you have a logic probe, check pin 40 of the 6502 and see if that is pulsing. If it is, then either your watch dog is barking or your reset circuit has an issue.

If the watch dog isn't barking (pulsing) and the reset is, then you probably do have a bad RAM or something to do with the RAM (like address decoding, etc..)

RAM should be 2114's located at E2 and D2 (if yours doesn't have one at D2, that would seem strange based on the schematics).


EDIT: I just re-read your first post. Is the game up and running and just having problems or is it not up and running at all?

 

[csa3d]

Your voltages don't look that far off. You need to check the voltages at the board.

If you have a logic probe, check pin 40 of the 6502 and see if that is pulsing. If it is, then either your watch dog is barking or your reset circuit has an issue.

If the watch dog isn't barking (pulsing) and the reset is, then you probably do have a bad RAM or something to do with the RAM (like address decoding, etc..)

RAM should be 2114's located at E2 and D2 (if yours doesn't have one at D2, that would seem strange based on the schematics).


EDIT: I just re-read your first post. Is the game up and running and just having problems or is it not up and running at all?

The game is not running at all. It appears to be failing self test on the RAM chips. I just discovered that in the PDF manual I'm looking at, the Parts List says that ram locations are L2, M2, M4, N4, P4, R4 while the Self Test page says D2, E2, M4, N4, P4, R4. If all the chips are to be 2114's, then the Self Test chart is incorrect on the PDF manual.. because all the chips at the parts locations all match 2114.

Lemme run some results and get back to you on the watchdog.

Thanks!
-csa

EDIT: Newb alert... What's a 6502? Scanning pdf now..

 

[ArcRevival]

the big question is do you have +5 at the main board ?

 

[csa3d]

the big question is do you have +5 at the main board ?

I'll check the voltages at the board tonight.

Also, is it possible to test the barking thing with a multimeter or do I need another tool for that?

-csa

 

[csa3d]

the big question is do you have +5 at the main board ?

I put the black on the ground, red to the loop marked +5. Voltage holds steady at 5.00vdc

 

[csa3d]

I've put in an order for a logic probe, should arrive Thursday so I can check the barking watchdog.

Is there something I can do in the meantime to test the monitor? Should I be getting some sort of image on the screen in test mode if I do indeed have bad ram?

-csa

 

[csa3d]

Your voltages don't look that far off. You need to check the voltages at the board.

If you have a logic probe, check pin 40 of the 6502 and see if that is pulsing. If it is, then either your watch dog is barking or your reset circuit has an issue.

If the watch dog isn't barking (pulsing) and the reset is, then you probably do have a bad RAM or something to do with the RAM (like address decoding, etc..)

RAM should be 2114's located at E2 and D2 (if yours doesn't have one at D2, that would seem strange based on the schematics).


EDIT: I just re-read your first post. Is the game up and running and just having problems or is it not up and running at all?

I have tested pin 40 of the 6502, and it tests as constantly being high. Does this test satisfy the watchdog test, or is that a separate test. If it's a separate test, can anyone tell me how to test that now that I am the proud owner of a logic probe?

Also on the good news front, today I realized there is a single point of light in the middle of the monitor, and no LEDs lit up on any boards in the monitor. I can hear what I"m guessing is "chatter", but my board is still not passing self tests.

Is the next step to purchase 6 things of new 2114 ram? Do I need to buy a HV diode or should I run with the one I have? I've read these are sometimes suspect as well.

-csa

 

[Arcadenut]

I have tested pin 40 of the 6502, and it tests as constantly being high. Does this test satisfy the watchdog test, or is that a separate test. If it's a separate test, can anyone tell me how to test that now that I am the proud owner of a logic probe?

PIN 40 is the reset pin on the CPU. If that pulses, the game will never start. So it being HIGH is a good thing.

Also on the good news front, today I realized there is a single point of light in the middle of the monitor, and no LEDs lit up on any boards in the monitor. I can hear what I"m guessing is "chatter", but my board is still not passing self tests.

Is the next step to purchase 6 things of new 2114 ram? Do I need to buy a HV diode or should I run with the one I have? I've read these are sometimes suspect as well.

-csa

If the self test is accurate and there is a bad RAM then it wouldn't hurt to get some RAM. If you can, remove the current RAM and put sockets in their place. You can then swap a few of the RAMS around and see if you get a different result.

Someone with a lot more experience with Asteroids could probably give you more things to look at.

 

[csa3d]

PIN 40 is the reset pin on the CPU. If that pulses, the game will never start. So it being HIGH is a good thing.




If the self test is accurate and there is a bad RAM then it wouldn't hurt to get some RAM. If you can, remove the current RAM and put sockets in their place. You can then swap a few of the RAMS around and see if you get a different result.

Someone with a lot more experience with Asteroids could probably give you more things to look at.

Thanks for all your help on this. I agree that if I'm gonna go through the trouble of replacing the ram, i'm gonna socket those puppies for anything that might come up in the future.

Time to email Bob again for some more parts!

-csa

 

[csa3d]

I need some help from the Asteroids gurus here.

I've removed all 6 banks of 2114 ram from the PCB, socketed the connections, and filled them with new ram from Bob Roberts. I've also replaced a broken 22 Ohm resistor at R4 which I discovered in the process.

Now when I boot up the game, with only the first RAM chip installed, I get one high beep, one low beep as expected. If I install the 2nd ram chip, I get two low beeps.. which is weird.. because it's my understanding I should hear two high beeps then a low beep if I'm assuming RAM three has an issue.. OR.. hear again one high beep one low beep meaning RAM two has an issue. Both beeps being low is throwing me off.

Since the chips are now socketed, I've tried every ram chip I have in slot two and get the same results.

I've also noticed that the tone of the beeps is now different since the ram swap-out, and that before my coin lights would blink and now they are solid.

Where do I go from here? I'm stumped.

-csa

 

[Arcadenut]

I've also replaced a broken 22 Ohm resistor at R4 which I discovered in the process.

If the board was physically damaged, you should start by looking for more damage. Look for broken traces, and pins that might be touching another pin or touching the back side of the board.

 

[csa3d]

If the board was physically damaged, you should start by looking for more damage. Look for broken traces, and pins that might be touching another pin or touching the back side of the board.

I'll for sure go back and this again, I spent a good while last night looking really closely at the back of the board and doing continuity tests at various locations. Maybe fresh eyes on a new night will help this..

Is this one of those things where thinking what I probably need to do is figure out what happens in what order upon boot, and verify that each event is happening correctly beginning from the last known working position? If so, where is that spot assuming 1 chip passes beep test properly and two ram chips acts oddly?

-csa

 

[csa3d]

Bump. So is it time I contact someone about board repair? If so, does anyone have any recommendations on who to contact about that? I'm living in Dallas, TX btw..

If there are more tests I can do, lemme know as well. I hate being stumped right now..

-csa

 

[csa3d]

Here's some shots of my ram swap out. It's not a pristine job like came with the board, but all the traces appear to be properly connected and not shorting or disconnected.

 

[csa3d]

more pics from above..

 

[ArcRevival]

all the traces appear to be properly connected and not shorting or disconnected.

The only way to know that for sure is to meter them. Does the manual specify what chip is bad for one beep ?