Need help with system 11 high speed

OP
Quoted from SPARKY70:
H
When I turned the game back on, I got some strange behavior of numerous coils firing on and off.
I immediately turned it off.
When I turned it back on, it played fine again.
not sure if this is just coincidence, or something i caused
It seemed fine the rest of the time while it was on. The next morning, I had issues again, but after turning it off and back on, it started up fine.
However, the next cold start, I had issues again.
...
Also if I turned it off and back on when it has been warmed up, it continued to work fine.

Since all this started when you went to do some cleaning, I would suspect that either you accidentally shorted some switch to power, maybe solenoid power, when you were mucking around in it. This would likely cause some severe damage to the MPU.

Or, you possibly pulled on a cable or harness (did you lift the playfield, by chance?) This may have disturbed something in the backbox.

It very well could be coincindence. Some of what you are saying about the cold vs. warm startups indicate you might need to evaluate the health of the power supply. That would be a good start, get a DMM and check the 5VDC rail for level and AC ripple.

Sorry I can't be more specific at this time.

#3 9 years ago

SPK

SPARKY70

Pinside member

Thanks for the help wayout.

I didn't lift the playfield when I was cleaning.

I don't see any disconnected cables.

I just checked test point 2 with my dmm, I'm getting 4.75-4.78.

I'm not sure what you mean by the 5 volt rail or how to check for ripple or level.
I'm new at this, but I can follow directions very well. Thanks. Sparky

#4 9 years ago

DAV

wayout440

Pinside member

OP
Quoted from SPARKY70:
Thanks for the help wayout.
I didn't lift the playfield when I was cleaning.
I don't see any disconnected cables.
I just checked test point 2 with my dmm, I'm getting 4.75-4.78.
I'm not sure what you mean by the 5 volt rail or how to check for ripple or level.
I'm new at this, but I can follow directions very well. Thanks. Sparky

No problem, Sparky. That 5VDC level is low, and that's a likely cause of the intermittent boot up failures. To check for AC ripple set your meter to the lowest AC setting and measure the same test point for the 5VDC. If the filtering is failing, you'll have too much AC there, something less than .5 (500mV) AC is probably ok. If you are measuring something over a volt, your filter capacitor for the 5VDC is probably in need of replacement. Is this the original supply on the game? Have you ever serviced it?

#5 9 years ago

SPK

SPARKY70

Pinside member

Thanks for the additional help.

I just tried the AC test at TP2.
I got a zero reading.

Also I want to make sure I clearly described my startup issue.

When I would turn it on, it would immediately start firing random coils repeatedly, which I believe we're on 3 different circuits since 3 different coil fuses blew on seperate occasions. F4, F2, and another 2.5 coil fuse that is not on a circuit board. Is is mounted to the backplate of the backbox near the lower right corner.
After shutting it down once or twice, (or possibly more) it would successfully go into game over mode.

Just want to make sure I describe it as accurately as possible. Thanks. Sparky

#6 9 years ago

DAV

wayout440

Pinside member

OP
Quoted from SPARKY70:
Thanks for the additional help.
I just tried the AC test at TP2.
I got a zero reading.
Also I want to make sure I clearly described my startup issue.
When I would turn it on, it would immediately start firing random coils repeatedly, which I believe we're on 3 different circuits since 3 different coil fuses blew on seperate occasions. F4, F2, and another 2.5 coil fuse that is not on a circuit board. Is is mounted to the backplate of the backbox near the lower right corner.
After shutting it down once or twice, (or possibly more) it would successfully go into game over mode.
Just want to make sure I describe it as accurately as possible. Thanks. Sparky

Hmmm. Sounds like the coils are locking on, blowing the fuses. Probably best to disconnect everything except power @1J17 and start troubleshooting from there.

"Remove all Unneccessary Connectors Before Starting. Before you power on a locked up CPU board, it's a good idea to remove all connectors from the board that aren't needed. This will limit the "cascading" effect that could possibly damage other boards."
http://techniek.flipperwinkel.nl/wms11/index2.htm

#7 9 years ago

SPK

SPARKY70

Pinside member

Ok, I marked and removed all connectors except for 17.

TP1 on CPU=zero ohms ground
TP2 on CPU = 4.84

test for +5 volts at U15 (the 6808 CPU) at pin 8. About 4.84

The 2764 EPROM at U26 and the 27256 EPROM at U27 will have +5 volts at pin 28. Both have about 4.84

The 6821 PIA's at U10, U38, U41, U42, U51, U54 will have +5 volts at pin 20.
All have about 4.84 except U51 which has 4.77

On power suppy board:
TP1=4.96
TP2=zero ohms ground
TP3=12.50
TP4= -14.40

Are these numbere within tolerance?

#8 9 years ago

DAV

wayout440

Pinside member

OK, the supply voltages look good enough. I don't see that as the problem. Now you will need to use a scope or logic probe to start examining the solenoid drive logic & PIAs to determine where this random activity is originating. You should probably also test the solenoid transistors to see if any are damaged or shorted. If you can get it to boot, I would also jump into diagnostics and look at the switch test mode, this is to make sure the switch matrix is not reporting switches are closed back to the CPU (there should be none, since the cables for these are disconnected)

Photos of the motherboard may help reveal other clues. Very hot chips (burn your finger hot) or dark spots or brown rings on the surface may indicate failed ICs. No corrosion at the battery holder, right?

---See also ---

"How did your game "die"? (the "cascading" effect)
The way in which your CPU board died can be important. For example, did a coil lock on just before the game died? If so, more than the driver transistor could have been effected. It could have "cascaded" back beyond the driver transistor, and to the driving PIA itself. If the PIA failed, this can cause a CPU board to be "locked up".

Here's another example of the cascading effect. Say you were playing a game, and the high voltage for the score displays blew a fuse, and the game locked up. Again, this problem could have back-tracked it's way to the CPU board, and killed the PIA.

If you don't know how your game died (for example, you just bought the game already "dead"), carefully look for evidence of problems. What fuses were blown? Look at the PIA chips and notice any "black ring" in the center of the chip (indicating the PIA got really hot at one time).

The Six PIA's and What they Control.
The 6821 PIA chips at U10, U38, U41, U42, U51, U54 can stop a CPU board from booting. Note all six PIA's connect to the CPU reset and IRQ circuits. Here's what each of the six PIA's controls:

U10: Sound output selects, solenoid drives, CPU board flipper relay K1.
U38: Switch matrix columns and rows, special solenoids A & D.
U41: Score display data (1J22), special solenoids B & C.
U42: Sound board (1J21)
U51: Score display circuit (1J1, 1J2, 1J3).
U54: Lamp matrix columns and rows, special solenoids E & F."

#9 9 years ago

SPK

SPARKY70

Pinside member

hi wayout, thank you for your continued help.

last night (Monday), i decided to take out my cpu board, to have a closer look at everything, and do some tests.

chip U41's pins all looked tarnished, so i pulled the chip out of its socket, and cleaned the legs (a little) with an eraser.

since ive had the game, the board was a little burnt by transistor Q79 (upper flashers) from someones prior repair
and Q69 (lower left jet) slightly burnt and a trace lifted for the same reason.
however the game always played fine like this.

also i believed that the transistor for the police light beacon (Q24) was bad because the light was always on when i got it. i had unplugged the connector for the beacon, and also turned it off in the settings to keep it from running all the time.

i tested all the transistors, and all were good, except for Q24 as i had suspected. i didnt replace it because i didnt have one on hand, and didnt want to make any changes to the situation yet.

so basically, the only thing i did to the board, was clean the legs of chip U41 a little.

i decided to put the board back in, and see if that made any difference.

as soon as i put the everything back together, it started right up, and went into game over mode without any issues. i ran it through all the tests, with no issues. including no switch edge issues.

i really couldnt believe it, but it played like it should.

i was reluctant to turn it off to see what would happen at the next power on, but it had to be done, and it worked again.

i played it a bunch of games to feel it out, then finally turned it off and went to bed.

this morning, i wanted to see what would happen from a cold start, and it started right up, and played fine, and after 2 additional power offs, its still going.

i dont feel too confident yet, that it will continue to keep working, but im keeping my fingers crossed for now..

now im not sure if this is just coincidence or if the tarnished legs could have caused my issues.

one thing i did notice, is that when i press on U41 my display segments get a little funny on player 1 and player 2.

also, there is no obvious acid damage that i can tell.

what are your thoughts on this whole scenario? thanks/sparky

picture below was before i cleaned the chip legs.

photo.JPG

below is after reinstallation

photo_1.JPG

photo_2.JPG

#10 9 years ago

DAV

wayout440

Pinside member

Well, glad you have it working - at the moment anyway. It's certainly possible that it may run for a long time. I don't think that the PIAs (U41 specifically) are usually socketed. I don't have my HS anymore, but they are soldered in on my other system 11s. This would lead me to believe it was replaced at some point. Maybe it was for corrosion at one time or maybe some other failure. If the work was done very well this can be hard to determine without looking at the soldering under high magnification from the back of the board.

Sockets have some characteristics that make them a weak link in an electronics circuit, and really should be avoided except for parts that are intended to be changed frequently, such as firmware ICs. It really doesn't take a much of a problem for them to introduce a resistance that is a problem, even if the pins are clean. Quality of the part important, especially the spring tension of the pins holding it in. Frequent removal can reduce the spring tension - the pressure on the pins. Oxidation getting in will introduce resistance, then the signals get misinterpreted. Over time, changes in temperature as the parts heat up and cool the chip can even push up out of the socket a little. This phenomenon has a formal name - "chip creep". Simply pushing the IC down in its socket completely can correct the problem.

If you want to be more certain the problem is resolved if it returns again, I would remove the socket and directly solder a brand new replacement part in it's place. Pressing on U41 like you did, well it is likely either the socket, the soldering of the socket, still having some oxidation on the pins, or possibly even broken leads internal to the chip. The little "legs" of the IC have very very fine wires that attach them to the actual integrated circuit inside the package. These can become broken and intermittent as well.

BTW Those alkaline batteries should be moved off board into a remote holder. Even if you think you will change the batteries in a timely fashion you could forget, or even new batteries could become defective. If they ever leak it can become a real problem.

Enjoy playing some HS!

#11 9 years ago

SPK

SPARKY70

Pinside member

https://pinside.com/pinball/forum/topic/high-speed-clear-ramp

Hi wayout, thanks again for all you help!!

I appreciate you taking your time to give very good and precise explanations. I'll be putting in a remote battery holder soon.

As for the U41 chip, I'm guessing that I could just put in an identical chip to replace it.
I don't think it would have to be game specific. Am I right?

Id leave the socket alone, unless I still have a problem then I would look into the socket.

Now that I've got it running again, I've got to finish cleaning and replacing the rubbers.
I've got the ramps all off. I'm trying to figure out how to get the back panel off by the diverter.

I believe it looks like 6 screws that are screwed in from the rear towards the front of the playfield.

Also, the way the rubbers are on there now don't look correct to me. Do you or anybody else know how these are supposed to lay?

Here is a pic. I'm guessing that both 5" rubbers should extend to the furthest post. I don't think the one laying against the playfield is of much use there either. Should the top one go in the groove, and the bottom rubber just under it or bottom in groove and top rubber sitting on top of the other so it doesn't slide down?

Also the plastic that attaches to the leftmost rubber post has a nut UNDER the plastic with nothing on top. I'm guessing that that is wrong too.

Anybody know? Thanks. Sparky

image.jpg

image-342.jpg

#12 9 years ago

NPS

floyd1977

Pinside+ Frequent

Schererville, IN

11y 78,550 1,719 7

You're right, both 5" bands should go around the outer posts. One band goes in the grooves, and the other goes right below it, with maybe a little gap in between:

#13 9 years ago

DAV

wayout440

Pinside member

OP
Quoted from SPARKY70:
Hi wayout, thanks again for all you help!!
I appreciate you taking your time to give very good and precise explanations. I'll be putting in a remote battery holder soon.
As for the U41 chip, I'm guessing that I could just put in an identical chip to replace it.
I don't think it would have to be game specific. Am I right?
Id leave the socket alone, unless I still have a problem then I would look into the socket.

No problem. Yes - that IC is not "game specific". You can replace only the IC and leave the socket alone if the socket looks clean and the soldering looks good.

#14 9 years ago

SPK

SPARKY70

Pinside member

Thanks Floyd and Wayout!!

I think the metal nut on the plastic should probably be there to hold the metal post securely, then most likely a plastic acorn nut on top of the plastic to secure it. Can anyone confirm? Thanks. Sparky

#15 9 years ago

MMD

Freeplay40

Encore Pinball

Bothell, WA

10y 127K 4,007 13

OP
Quoted from SPARKY70:
Thanks Floyd and Wayout!!
I think the metal nut on the plastic should probably be there to hold the metal post securely, then most likely a plastic acorn nut to secure it. Can anyone confirm? Thanks. Sparky

Just the acorn is all that is needed. As far as your chip problem, no sense in replacing the chip if it is working... The problem is the chip socket....common stuff on these games.

#16 9 years ago

SPK

SPARKY70

Pinside member