System 1 Rom and continuous scoring

Have you done a switch test to see what switch(es) are being activated?

#3 6 years ago

???

Sonora70

Pinside member

Quoted from ForceFlow:
Have you done a switch test to see what switch(es) are being activated?

Short answer is no. Not sure the switch test would tell me anything? The continuous scoring doesn't occur until the drop target switches are dropped. Doesn't seem to do it at any other contact. The drop target switches remain "connected" when they are dropped. They should only score once but they continue to score.

#4 6 years ago

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ForceFlow

OP
Quoted from Sonora70:
Not sure the switch test would tell me anything?

It would tell you if a switch is closed when it shouldn't be.

After eliminating any potential physical issues with switches, then you would proceed to test for switch matrix issues.

#5 6 years ago

???

Sonora70

Pinside member

Started working with the pin again this morning. The continuous scoring is with the spinner and drop targets. It will not go into test mode either which is a new development. Could my new 7405 and 7404 chips be bad?

#6 6 years ago

???

Sonora70

Pinside member

When the test switch is pressed a new game starts

#7 6 years ago

III

ripple

Pinside+ Frequent

Boise, ID

9y 78,900 306 4

I had a scoring issue that was fixed with a new socket for the ROM chip. I'd think if the ROM was bad it would not work at all.

#8 6 years ago

???

Sonora70

Pinside member

Quoted from ripple:
I had a scoring issue that was fixed with a new socket for the ROM chip. I'd think if the ROM was bad it would not work at all.

Thx for the tip. Will try and report back.

#9 6 years ago

BIF

CactusJack

Pinside member

OP
Quoted from Sonora70:
When the test switch is pressed a new game starts

That makes me think you have a switch strobe (output) either shorted to ground or stuck low (bad IC).

Check start button blades and coin switches (especially the coin lock out wiskers).

If you have done the slam switch mod on the MPU, You can start a game and then unplug the edge connector that goes to the cabinet switches and see if the playfield behaves normally.

#10 6 years ago

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ForceFlow

http://pinwiki.com/wiki/index.php?title=Gottlieb_System_1#Switch_Matrix

Quoted from CactusJack:
That makes me think you have a switch strobe (output) either shorted to ground or stuck low (bad IC).
Check start button blades and coin switches (especially the coin lock out wiskers).
If you have done the slam switch mod on the MPU, You can start a game and then unplug the edge connector that goes to the cabinet switches and see if the playfield behaves normally.

Additionally, check the strips of diodes in the cabinet and on the underside of the playfield. Those are part of the switch matrix, and if one of those is shorted, then you will get odd behavior. Note that you can't replace those with 1N4004 or 1N4148 diodes, unfortunately--you'll have to use a 1N270 or CDSH-270 germanium diodes.

#11 6 years ago

???

Sonora70

Pinside member

Thanks for the tips, I'll take a look and do a follow up. Not sure what it means but all the switches that are causing the continuous scoring as well as the test switch are on the same row on the matrix.

#12 6 years ago

BIF

CactusJack

Pinside member

https://pinside.com/pinball/forum/topic/system-1-driver-board

It means that the "strobe" they all share in common is stuck low. Could be a ground short or a bad Output IC.

Similar discussion here including snippet of the SW matrix showing the 7404 strobe drives.

#13 6 years ago

CHK

ckcsm

Pinside member

8y 48,300 414

Quoted from ForceFlow:
Additionally, check the strips of diodes in the cabinet and on the underside of the playfield. Those are part of the switch matrix, and if one of those is shorted, then you will get odd behavior. Note that you can't replace those with 1N4004 or 1N4148 diodes, unfortunately--you'll have to use a 1N270 or CDSH-270 germanium diodes.

I found plenty of choices on Ebay, I just ordered some for my Joker Poker

ebay.com link: BKC International 3658AMO302701 1N270 Germanium glass diodes lot 100

#14 6 years ago

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ForceFlow

Quoted from ckcsm:
I found plenty of choices on Ebay, I just ordered some for my Joker Poker
ebay.com link » Bkc International 3658amo302701 1n270 Germanium Glass Diodes Lot 100

I don't think I'd ever use that many. Out of all the sys1 games I've worked on, I've probably used less than 10 of those diodes.

#15 6 years ago

???

Sonora70

Pinside member

Quoted from CactusJack:
It means that the "strobe" they all share in common is stuck low. Could be a ground short or a bad Output IC.
Similar discussion here including snippet of the SW matrix showing the 7404 strobe drives.
https://pinside.com/pinball/forum/topic/system-1-driver-board

I'll take a look at the switches on the coin door tomorrow and plug in a new 7404 chip as well.
I just replaced it, but maybe faulty? Glad I put sockets on the board.

#16 6 years ago

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ForceFlow

OP
Quoted from Sonora70:
I'll take a look at the switches on the coin door tomorrow and plug in a new 7404 chip as well.
I just replaced it, but maybe faulty? Glad I put sockets on the board.

Do you have a chip tester? That takes out some of the guesswork when it comes to 7400 series chips.

ebay.com link: sch

#17 6 years ago

???

Sonora70

Pinside member

Quoted from ForceFlow:
Do you have a chip tester? That takes out some of the guesswork when it comes to 7400 series chips.
ebay.com link

I don't. I'm just beginning to venture into the solid state pinball. Not sure what equipment I need.

#18 6 years ago

BIF

CactusJack

Pinside member

But if they all share the same switch return line, then it may be a bad 7405 or associated components.

Again, if you haven't done the slam switch mod jumper, you can jumper a cap on the MPU board with an alligator clip jumper. This way, you can unplug both the playfield matrix (J7) and the lower cabinet matrix (J6) to see if the issue is coming from wiring.

#19 6 years ago

RNA

LynnInDenver

Pinside member

Denver, CO

8y 38,300 373 1

Is it a brand new modern power supply, or one transplanted from another machine? We had the same problem with Solar Ride, with spurious bonus increases and acting like the entire bank of drop targets had been dropped, and the switch test was showing switches that didn't actually physically exist in the switch matrix being triggered. It turned out to be the power supply (which came from another System 1) was no longer giving good voltage. The machine finally just started locking up. I replaced the power supply with a new build from Gulf Pinball via Marco (I decided I didn't want to fiddle with the old ones anymore), and it's been (almost) rock solid since. I think I've had two instances of "four targets dropped, machine thinks all five are", and I've got capacitors to replace the MPU power filter capacitors and replacement 7405 chips now on hand in case it does that again.

#20 6 years ago

???

Sonora70

Pinside member

Problem solved....... I replaced the new 7404 chip I put in a couple days ago. It is now working correctly. I assume the chip went bad or was defective? At any rate, I played several games today and it worked well.

Thanks much for all the tips and help. Some good ideas to help isolate issues.

#21 6 years ago

???

Sonora70

Pinside member

Quoted from LynnInDenver:
Is it a brand new modern power supply, or one transplanted from another machine? We had the same problem with Solar Ride, with spurious bonus increases and acting like the entire bank of drop targets had been dropped, and the switch test was showing switches that didn't actually physically exist in the switch matrix being triggered. It turned out to be the power supply (which came from another System 1) was no longer giving good voltage. The machine finally just started locking up. I replaced the power supply with a new build from Gulf Pinball via Marco (I decided I didn't want to fiddle with the old ones anymore), and it's been (almost) rock solid since. I think I've had two instances of "four targets dropped, machine thinks all five are", and I've got capacitors to replace the MPU power filter capacitors and replacement 7405 chips now on hand in case it does that again.

I actually have a new rottendog power supply.

Quoted from CactusJack:
But if they all share the same switch return line, then it may be a bad 7405 or associated components.
Again, if you haven't done the slam switch mod jumper, you can jumper a cap on the MPU board with an alligator clip jumper. This way, you can unplug both the playfield matrix (J7) and the lower cabinet matrix (J6) to see if the issue is coming from wiring.

I looked for this mod some today and couldn't find a clear description of it.......I've read/seen it but just couldn't get my hands on it when I needed it.

#22 6 years ago

BIF

CactusJack

Pinside member