SOLVED -System-1 Won't Boot

(Topic ID: 230787)

SOLVED -System-1 Won't Boot


By JethroP

15 days ago



Topic Stats

  • 37 posts
  • 4 Pinsiders participating
  • Latest reply 12 days ago by JethroP
  • Topic is favorited by 1 Pinsider

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#1 15 days ago

Picked up a non-working Close Encounters with System-1. Began by repining the connectors to the Control Board, cleaned up a little corrosion on the Control Board, and replaced 4 corroded resistors (R33, 34, 37, 38). Repaired the power supply board that was not working, so all voltages to the Control Board are correct.

I am following Clay's step by step guide on powering up a System-1 game for the first time. The power supply is connected to the Control Board (A1-J1), and the two connectors on the right side of the Control Board are connected (A1-J2, J3). Nothing else is connected to the Control Board. When I turn the power on, the two upper displays show all zeros, and the two lower displays are blank, except for a few strobing segments. I suspect Z17 is bad (or something else?). After a minute or so I noticed Z17 got hot to the touch. Z16 was not hot at all. Any suggestions the experts can offer? I'm a mechanical engineer, not electrical

#2 15 days ago

Looks like Z17 controls the display segments. I would recommend disconnecting the two lower displays, in case one of them is shorted, and that's whats cooking your Z17

#4 15 days ago

I disconnected the two lower displays. Z17 still gets hot.

#5 15 days ago

If Z17 is getting too hot to touch especially compared to Z16 which is the same chip, then your instincts are probably right and it's fried.
This might sound odd, but take a sniff of the area around Z17 with it on. You might notice it giving off a certain smell. Next time you're working on a logic board and notice that smell you'll know somethings cooking.

#6 15 days ago

Ok. Before I replace z17 is there anything I should check, or anything I should check immediately after replacement before the new chip has time to fry?

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#7 14 days ago

The heat check is a very good indicator that Z17 is faulty especially if it gets hot within a minute and it's twin neighbor at Z16 stays cool and produces valid digits.

You can put one of the working displays onto the output of that Z17 chip - i.e. move the display at player 1 to the player 3 position and see if you now get legible digits.
Download the datasheet for the 7448 chip at Z17 which is a 'BCD to 7 segment decoder'. The logic datasheets usually have a truth table indicating how the outputs react based on the state of the inputs. That datasheet also lists all the output numeric display combinations which can help determine if it's producing valid outputs (presuming you have no connectivity issues from the MPU board to the display).

Any chance someone has socketed your Z16 and Z17 chips in the past so you can swap them around?

#8 14 days ago

Unfortunately Z16, 17 are not socketed. I have removed Z17 and installed a socket. Ordering a new SN7448. So this thread will be on hold a while

#9 14 days ago

I have removed Z17. Would it damage anything to try to boot the game without it to see what other issues I might have? Clay's guide says one step at a time....get the displays working before plugging in the driver and lamp board. I'm thinking if I have to place an order for parts, it would be nice to know what else I might need (assuming I still have boot problems). Or maybe the game won't boot without all the displays working?

#10 14 days ago
Quoted from JethroP:

Would it damage anything to try to boot the game without it

Nope. The things being driven by that chip just wouldn't activate/respond.

#11 14 days ago

So with the Z17 removed I connected everything and powered the game on. After about 5 seconds the tilt and game over relays clicked, the displays lit up (more on this later), so does this mean a successful boot? I can't start a game.

Not sure what is supposed to happen at this point. There is still a display issue. I understand the two lower displays are showing all 8's, but there is no Z17. The two upper displays alternate between all zeros and High Score, but some of the high score digits are missing. Also, the Ball in Play is showing 70. See pics.

When I press the credit button nothing happens.

When I drop a coin (or trip the coin switch) nothing happens. The coin mech solenoid is activated.

None of the feature lamps are flashing, as I assume they would in attract mode.

Is my Control Board history, or is there some hope of repair? Thoughts and suggestions welcome. Thanks.

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#12 14 days ago
Quoted from JethroP:

The two upper displays alternate between all zeros and High Score, but some of the high score digits are missing.

You have corrupt data in the battery backed RAM. Go and clear the book-keeping audits and reset the score level awards and highest score thresholds.

Quoted from JethroP:

Also, the Ball in Play is showing 70. See pics.

Quoted from JethroP:

None of the feature lamps are flashing, as I assume they would in attract mode.

PinMAME does the same thing showing 70 in the Ball in Play display on powerup so presume it's normal. It also doesn't show any lamp attract mode sequence so it's also probably normal that no lamps are flashing.

At this point you should try and go into test mode and look for switch and solenoid/relay issues.

#13 14 days ago

Pressing the self test button doesn't do anything.

#14 14 days ago
Quoted from JethroP: None of the feature lamps are flashing, as I assume they would in attract mode.

Actually, Sys1 boards don't have an attract mode, beyond a 555 flasher behind the "Game Over" in the backglass.

Seems you are pretty far along. I would say your board has hope.

Under the playfield, on the left side of the control panel is a diode board. This is for the coin door / credit button switch strobes If these diodes are broken or missing, you won't be able to coin up or start a game

#15 14 days ago

Also, I would leave the bottom displays disconnected, in case there is a short in one of them that's killing your Z17.

#16 14 days ago
Quoted from songofsixpence:

Seems you are pretty far along. I would say your board has hope.

That's encouraging. Thanks. But read on....

Quoted from songofsixpence:

Under the playfield, on the left side of the control panel is a diode board. This is for the coin door / credit button switch strobes If these diodes are broken or missing, you won't be able to coin up or start a game

The diodes are there and check out ok. Now what?

#17 13 days ago

Make sure to clean the edge connector contacts on the MPU with a pink rubber eraser to remove any surface grim/tarnish. That has made a difference on system 1 boards more times than I can count.

#18 13 days ago

I think I found the problem. A few bad traces I missed the first time after I did the corrosion repairs. I am going to have to replace a few edge contacts on the board. Never done that. But I'm pretty confident that is the problem.

#19 13 days ago

Progress...repaired the bad edge connections on the Control Board. Now am able to go through the self test. Each step through the test (the audits), show gibberish. I can reset them to zeros, however I do not have a battery connected to the control board, so when I power off and back on the game, the weird gibberish still appears. Is this a bad RAM chip(s)? The feature lamps and solenoids all function during the test. HOWEVER, when I press the credit button I get a few beeps like a game is starting....but the game does not start.

#20 13 days ago
Quoted from JethroP:

Each step through the test (the audits), show gibberish. I can reset them to zeros, however I do not have a battery connected to the control board, so when I power off and back on the game, the weird gibberish still appears. Is this a bad RAM chip(s)?

No, you need the battery to preserve the audit settings. Without the battery you will always get garbled diplays

Quoted from JethroP:

The feature lamps and solenoids all function during the test. HOWEVER, when I press the credit button I get a few beeps like a game is starting....but the game does not start.

So, when you start a game, the Player One display should blink all zeros and the ball is served. Are you saying that neither of these things happen?

#21 13 days ago
Quoted from songofsixpence:

So, when you start a game, the Player One display should blink all zeros and the ball is served. Are you saying that neither of these things happen?

Correct. When I press the credit button I get a multi note tone and the displays quit alternating to show high score. The displays show non- flashing zeros, except he status display. It shows 9 and 70. BTW, I still don't have a chip in Z17 and the 3rd and 4rh player displays are unplugged.

#22 13 days ago
Quoted from JethroP:

the 3rd and 4rh player displays are unplugged.

Is everything still plugged in on the MPU? Those connectors have some shared wiring between all the displays.

#23 13 days ago

Everything is plugged into the MPU. Everything in the backbox is plugged in. Only thing unplugged now are the connections at player 3 and 4 displays.

#24 13 days ago
Quoted from JethroP:

Everything is plugged into the MPU. Everything in the backbox is plugged in. Only thing unplugged now are the connections at player 3 and 4 displays (and still no Z17 installed). Also to clarify my answer to your earlier question, when I press the credit button to start a game, the #1 player does not blink zeros. It shows non-blinking zeros.

#25 13 days ago

I remembered somewhere that Gottlieb EMs would not start a game, unless there was a ball in the outhole. I just tested that theory on my System 1. Mine does start game when the ball is in the shooter. So, no help there.

You did mention that the coils and feature lights will tested correctly. How about the switches? Do they register properly?

#26 13 days ago

Good question. The switches don't do anything when I test them, or I'm not sure how to test them.

#27 13 days ago

So I reread the self test procedure, and tested a few switches. They register correctly....at least 3 that I tested. I didn't test each switch. But none of the switches show to be stuck closed.

#28 13 days ago

Update: I started a game today! Sort of. Read in a few places that some System-1 control boards need the battery on board to start a game, so I wired up a remote battery pack and cleared all the audits in the self test. I was able to start a game with some issues. About 1/2 the play field switches don't work. Maybe they need cleaning? And the outhole solenoid does not fire. It did score points correctly on the switches that did work. Any suggestions welcomed. I'm guessing now I need to do some driver board work?

#29 13 days ago
Quoted from JethroP:

So I reread the self test procedure, and tested a few switches. They register correctly....at least 3 that I tested. I didn't test each switch. But none of the switches show to be stuck closed.

Yeah, not the most intuitive self-test system, but it works OK.

Quoted from JethroP:

About 1/2 the play field switches don't work. Maybe they need cleaning?

Possible, but I doubt it.
Do you have the manual? I would look to see if the switches that don't work are on the same column / row. Diode board for those is under the playfield. Also I would look closely at the MPU J7 connector. Were these repinned? These connectors are prone to battery damage.

I had recently a Solar Ride that many switches didn't work. Someone had previously worked that connector and got two of the wires mixed up.

Quoted from JethroP:

And the outhole solenoid does not fire. It did score points correctly on the switches that did work. Any suggestions welcomed. I'm guessing now I need to do some driver board work?

Could be any number of things. Possibly Q32 on the driver board. Could also be a connector problem, bad wire, bad coil, etc.

You said you could get into test mode. Are you able to test the solenoids? Do all of them fire in test? Does the outhole mech move freely?

#30 13 days ago

Yes all the switches that don't work are on the same row. I believe I found another bad trace at MPU J7. Repair in progress. I'll work on the outhole tomorrow. It was the only solenoid that did not fire during the test mode. The mechanism is free.

#31 12 days ago

Replaced a broken edge connector pad all switches are now working. Replaced a bad fuse under the play field and outhole solenoid is now working (thought I had checked that before...duh). So now everything plays correctly. Yay!

But there is an issue that is occurring that has me puzzled and could use some suggestions. If the game has been sitting off for a while (maybe a few minutes), and I turn it on, seems like all the solenoids fire immediately, the sound blasts a loud buzz-hisss, all this happens simultaneously, and the tilt and game over relays energize. Pressing the credit button doesn't do anything. If I turn the game off and right back on, then it boots normally and everything is fine. The slam switches are both closed as they should be (haven't done the slam switch mod), but I did jumper both switches just to confirm the switches are closed. Almost seems like a capacitor issue, that given a little time, something discharges and affects the start up. Help?

#32 12 days ago

I think you are still looking at a connector issue. Somewhere there is not a solid ground connection.

You are looking at the Achilles heel of the System 1. From Clay's guide:

First there is the problem with ground between *cabinet* ground, and circuit board ground. John Robertson documented this problem back in 1987. There is a single ground connection between the cabinet ground and circuit board ground on the power supply. If this single connection has resistance (which is common on older games), problems occur. This resistance, with the current drawn by the Driver board through the power supply, causes a voltage shift in the power supply's ground line. If the voltage shift gets up to .5 volts relative to the cabinet ground, the solenoid driver transistors are no longer biased off, and start to conduct. This can cause playfield coils to "lock on" and burn, damaging the coil and its associated driver transistor. This single problem made many people think Gottlieb games were "unreliable".

I suspect that with a bit more redundant grounding between the MPU, Driver, and power supply board that this issue would be resolved.

#33 12 days ago

I have done the ground mods as Clay recommended. I have grounded the PS, Control Board, and Driver board all to the back panel. I have looked over all the grounding connections in the bottom board as well and don't see any problems.

I believe if I had a grounding issue, the problem would be intermittent. The thing is, I can predictibly reproduce "the problem." If the game sits for 3 minutes or more and I turn it on, the aforementioned problem occurs. If the game has only been off for 2 minutes or less, and I turn it on, everything is perfectly normal.

#34 12 days ago

Can you tell if the driver board is a Rev. 1, or is it later? Later boards have 4 diodes at the top, near the connector for the MPU.

Quoted from JethroP:

Almost seems like a capacitor issue, that given a little time, something discharges and affects the start up.

Not too many caps beyond the power supply. Has this been rebuilt?

#35 12 days ago

It does not have the diodes. I've seen the mod but have not done it. Do you think installing the diodes is the cure?

The power supply has been rebuilt, all new electrolytics.

#36 12 days ago

The rest of my suggestions would be:

- New caps on the PS
- tie together the ground lines on the Driver Board
- diodes implemented between the driver and mpu (if not installed already)

You may take my advise with a grain of salt. I'm somewhat spitballing here, so if anyone has any solid suggestions, I would welcome them to chime in.

Congrats on your progress so far. CE is a fun game, and yours looks pretty good, from what I can see.

-dave

#37 12 days ago

Since I am able to boot and play I am marking this posting/thread as solved. I am going to begin a new thread just to discuss the Slam/Bang on startup. Thanks to all who helped me get my project up and running, especially Quench who helped me identify the failed components on my power supply.

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