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(Topic ID: 87835)

Taxi needs to warm up for several minutes before being playable?


By Whridlsoncestood

6 years ago



Topic Stats

  • 35 posts
  • 10 Pinsiders participating
  • Latest reply 10 months ago by koen12344
  • Topic is favorited by 4 Pinsiders

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Linked Games

  • Taxi Williams, 1988

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image-95.jpg

#1 6 years ago

Something that I should of taken care of earlier before I started my restore is this issue I am having. I got this taxi in as a train wreck. Got it working 100 percent and then started having a slight issue before I tore it down.

Game has pinscore LED displays so nothing is outgassing before I start.

When you first turn the game on only a few segments on the display come on. Maybe a couple more lfickering as well. Many inserts dim. CAB lights in the back lanes especially worse than the others. If you start a game immediately the coils are very week. Can't even shoot a ball in the outhole to the trough. After a few minutes coils are good and inserts are good and most of the display segments are back. After about 10 all the display segments are nice and bright.

When I started on the restore I did the cabinet first. When I cleaned all the boards I replaced C1, C3, C9 and C10 on the power supply board and the big blue capcitor on the lower right hand corner of the head. I plugged the old playfield back in outside of the cabinet for testing purposes and the issue is still there.

I'm guessing there is another capacitor I should be looking at replacing but I'm not sure which one. What seems odd to me is coils, displays and lighting are all different voltages. Wall voltage is fine.

Playfield is almost done being restored. Should be back in, in another day or two. I can still boot the game and check the displays without the playfield in though. Any other suggestions to look at?

-Jim

#2 6 years ago

Start by checking these test points (game cold). These I posted in the Williams bulletproofing thread. Taxi was one of the test games used to create this reference table. Once you/we start to compare them, we can give you some idea of what you might need to investigate.

*** Williams System 11 Power measurements and test points ***

Logic power
MPU IJ17 Pins 4,5,6 = +5.03 VDC @8.1 mV AC ripple
U26/U27 ROM Pin 1 = +4.91 VDC

Audio power
MPU IJ17 Pin 9 = -14.04 VDC (Unregulated)
MPU IJ17 Pin 8 = +12.02 VDC (Unregulated)
Audio board U11 (U17 on Sys11B) Pin 8 -13.9 VDC @250 mV AC ripple
Audio board U11 (U17 on Sys11B) Pin 4 +11.8 VDC @50 mV AC ripple

Controlled lamp power
PS 3J4 pins 5,6,7,8 (Sys11A) or backbox bridge 6BR1 (Sys11B)= +15VDC to +18VDC nominal.

General illumination power
PSU 3J8 (Sys11A) or Interconnect board output 2P7 (Sys11B) = 4.5 VAC to 6.3 VAC nominal

Display power
3J5 pin 3 (Sys11A) or 3J2 pin 3 (Sys11B) = +90 to +110VDC nominal
3J5 pin 4 (Sys11A) or 3J2 pin 1 (Sys11B) = -90 to -110VDC nominal

Flipper power
Game specific@flipper supply board outputs= +65 to +75 VDC nominal

Solenoid power
PS 3J3 pins 6,7,8 (Sys11A) +32 to +35 VDC
Interconnect board F1/F3 (Sys11B) +41 VDC
Interconnect board F4 (Sys11B) +75VDC

NOTES
Reference test games used:
Williams Pinbot - System 11A/D-8345-549 PS
Williams F-14 Tomcat - System 11A/Rottendog WDP-011A PS
Williams Taxi - System 11B/PinScore PJ-12246 Rev. B PS

#3 6 years ago

119.7 at service outlet. 119.7 at lines going to transformer when game turned on and cold.

Tested lines out of the transformer. All cold as well

White lines-88.5 on schematics. Reads 93.2
Grey/white. 9.7-reads 10.5
Grey/green. 9.7- reads 22
Blue/white-13.5-reads 14.4
White/red 26-reads 30.5
Black/yellow 48-reads 55

Testing voltages at coils. Some at 75. Others at 40. All tested cold.

Test points on power supply board
TP1 +5V reads 4.98
TP3 +12v reads 13.5
TP4 -12v reads 14.4

Also noticed flippers don't work at all until warmed up.

After the transformer these AC lines go to the power board and the auxiliary driver board to get rectified to DC voltages. Not sure where these voltages are going wrong. Transformer is the last common link between them.

-Jim

#4 6 years ago

Talking with My buddy Taxman it looks like this might just be a 5v issue. Coil voltage seems fine when game is cold. 5v opens the Predriver transitor to send higher voltage to open the coil transistor to ground. If I have good voltage to coil I must have a weak connection to ground. Possibly the 5v not strong enough to open the transistors properly. Same with lamps. Transistors not opening and displays the same thing. Pinscores run off of the 5v line. Test point on powerboard how 4.98 when cold so that's good. Possibly a cracked solder joint on the header pin going out.

Taxman has a new powerboard for taxi I can swap in. Will try that if re flowing the header pins doesn't fix it.

Oh and that way high reading I was getting on the grey/green line was because it was the common line of the 3 pair. I was using the grey line as common and hence it was a readig for 9.7+9.7=19.4 so my 22 is in line.

Sound logical to anyone else that this is just a 5v to CPU board issue?

#5 6 years ago

many times ive seen this on system 11 games , recap the 5v circuit on the power supply , its usually one of the little ones , forget which one exactly.

#6 6 years ago
Quoted from Astill:

many times ive seen this on system 11 games , recap the 5v circuit on the power supply , its usually one of the little ones , forget which one exactly.

I disagree without more specific readings that his power supply is suspect. He read 4.98VDC on the 5V power supply rail when cold, which should be fine. It would have been helpful if we had confirmation of what the ripple voltage was. A higher than normal ripple reading would be a giveaway the 5VDC section of the power supply needs attention. Also, the measurement of the 5V rail at the CPU board was not mentioned. A significant difference between the 4.98VDC on the power supply board and the CPU board at the test point mentioned (actually, VCC at any of the logic chips) would indicate a problem - most often connectors but can be other problems. Another note, you would likely have random game reboots if the 5VDC was not good.

Not sure if a typo, but some of the reported values are indicated as positive values when they should be negative values. Again, I think it a typo, but it should be confirmed.

I would be curious to know what the flipper supply board voltage is reading (cold) since the weak flips reported at startup when cold.

#7 6 years ago

My next step wen I get a chance is to measure 5v at the CPU connector and the 5v test point on CPU (assuming there is one, haven't looked yet) to see if there is a problem at the harness. I reflowed all header pins on the power board last night specifically the 5v pins. No change in behavior. Also I want to measure that 5v line and see if it rises from 4.98 as it gets warm. I have a decent meter but not really sure if it can read any ripple I may have.

I see now C8 is for the 5v line and will probably order some as its a good part to have on hand at the very least.

I have not checked but does taxi have a flipper engage relay? I don't have weak flippers at start up I have no flippers. Once warm they are on full strength. Again assuming weak voltage to relay engaging high voltage to flippers.

Won't be home for a couple days but will look into it first chance I get. This one is wracking my brain and I want to get it resolved. More of a nuisance as after a couple minutes game will work flawlessly for the day.

#8 6 years ago

Its time to reflow some header pins.

#9 6 years ago
Quoted from GRUMPY:

Its time to reflow some header pins.

Did the power board ones. Even though they looked perfect no change. Will check and do the CPU ones next chance I get.

#10 6 years ago
Quoted from Whridlsoncestood:

My next step wen I get a chance is to measure 5v at the CPU connector and the 5v test point on CPU (assuming there is one, haven't looked yet) to see if there is a problem at the harness. I reflowed all header pins on the power board last night specifically the 5v pins. No change in behavior. Also I want to measure that 5v line and see if it rises from 4.98 as it gets warm. I have a decent meter but not really sure if it can read any ripple I may have.
I see now C8 is for the 5v line and will probably order some as its a good part to have on hand at the very least.
I have not checked but does taxi have a flipper engage relay? I don't have weak flippers at start up I have no flippers. Once warm they are on full strength. Again assuming weak voltage to relay engaging high voltage to flippers.
Won't be home for a couple days but will look into it first chance I get. This one is wracking my brain and I want to get it resolved. More of a nuisance as after a couple minutes game will work flawlessly for the day.

You want to borrow my ESR meter? Will allow you to check all the caps in circuit in a couple of minutes (though I'm guessing its not your caps). I also have a spare 47uf 50v cap you can have...
I can also pick up my shirts while I'm at it...

viperrwk

#11 6 years ago
Quoted from Whridlsoncestood:

5v test point on CPU (assuming there is one, haven't looked yet)

This is TP2 right next to U21 under J17.

viperrwk

#12 6 years ago

Thanks Viper. I'm not free until begining of next week. If you want to come by next week that's cool. If your at Allentown I can get you the shirts there too.

I will let you know when I check TP2 on the CPU.

-Jim

#13 6 years ago

See the schematics - insert power is rectified directly from the transformer. A problem with the 5VDC rail will have no association with this.

#14 6 years ago

What controls the inserts though? Lamp matrix correct? What opens the transistors to ground? 5v like the coil ore driver transistors? All my voltages from transformer are fine. Everything warms up at same rate and time. There has to be one common link to all this.

#15 6 years ago
Quoted from Whridlsoncestood:

What controls the inserts though? Lamp matrix correct? What opens the transistors to ground? 5v like the coil ore driver transistors? All my voltages from transformer are fine. Everything warms up at same rate and time. There has to be one common link to all this.

The transistors are biased to saturate or cutoff, in other words, acting as switches - either open or closed. The lamps would be full on or full off - there would be no dimming. Same goes for the transistors operating the solenoids - they would not be weak if the 5VDC had a problem. Those transistors simply wouldn't turn on. If the transistor switch comes on, the lamp should be at full brightness, if it is dim - it's because the lamp supply voltage/current is low. That comes from a secondary on the transformer that runs through a bridge rectifier....it's own pipe if you can think of it that way.

Have you tried another known good transformer? There is the possibility that even though you are measuring voltages that appear correct...there isn't enough current supplied under load until the game warms up. Also, make sure those output pins and connector out of the transformer secondary are perfect. That's what I would be looking into first if it was me.

#16 6 years ago

Would this weak voltage to the lamps at the transformer only affect a few of the inserts? For example in the front center of the playfield. All passengers light up by there is an issue with the 4 playfield multiplier inserts and the green airport value inserts.
Also with LEDs in the weak dim inserts don't light at all until slowly one by one they come on as it warms up.

#17 6 years ago

This one has me scratching my head, I wish I was closer.

It seems like you've got some kind of resistance that is fading as something heats up. I would suspect an oxidized/worn/messed up connector or the transformer as my first go to. I think that's also what wayout is saying as well.

#18 6 years ago
Quoted from Wolfmarsh:

This one has me scratching my head, I wish I was closer.
It seems like you've got some kind of resistance that is fading as something heats up. I would suspect an oxidized/worn/messed up connector or the transformer as my first go to. I think that's also what wayout is saying as well.

I couldn't agree more. The hard part is finding which connector.

#19 6 years ago
Quoted from Whridlsoncestood:

Would this weak voltage to the lamps at the transformer only affect a few of the inserts? For example in the front center of the playfield. All passengers light up by there is an issue with the 4 playfield multiplier inserts and the green airport value inserts.

Weak supply to the insert lamps would affect them all, but you could have additional problems specific to those inserts.

Quoted from Whridlsoncestood:

Also with LEDs in the weak dim inserts don't light at all until slowly one by one they come on as it warms up.

That's a function of the LED being a semiconductor. LED = Light Emitting DIODE. It won't light up until the voltage overcomes the diodes P-N junction.

#20 6 years ago
Quoted from eabundy:

I couldn't agree more. The hard part is finding which connector.

7P2-7J2 connector out of the transformer. The only supply voltage not running through this output connector on the secondary of the transformer is the GI. If the GI is also dim, definitely would suspect the transformer (or something before it, input connector 7P5-7J5 perhaps), It might also be hard to discern if the GI was dim, unless it was really bad to be noticeable.

#21 6 years ago

GI has been great. No issues at all with it.

I obviously have a 5v issue somewhere at the least with the displays working off that. Lamp power would be the two 9.7v lines out of the transformer and coils the 26 and 48 lines. All test fine at pins from transformer at connector. Will try to test after that connector to see if I have a bad pin/connector connections seems odd that all of these pins would have to be equally flakey connections and how does this relate to the 5v issue since I have good 5b at power board? Also another equally flakey connection at CPU from power board perhaps. Very odd that multiple issues all "warmup" at the same rate. Also a bad connections will usually cut in/out when you wiggle connectors right? Can't make that happen with this.

I need to dig some good time in poking around again. Problem is I have limited time to test these things. Run a test. Turn it off quickly. Back on another test. Off quickly. After a couple tests I'm getting pretty warned up to no issues.

#22 6 years ago

Steady 4.94 at CPU TP2. Well above my buddies fully working taxi at 4.87. Looking at transformer connector now.

#23 6 years ago

No change on any behavior messing with transformer connector.

Tried disconnecting pinscore displays no change.

#24 6 years ago

Found this looking closely at CPU. Bad attempt as fixing acid

image-95.jpg

#25 6 years ago

You've got some cleanup work ahead of you.

#27 6 years ago

That's ugly. I'd have to question the long term reliability of some of those components, it looks like electromigration of the corrosives into some of the component bodies may be possible in this case.

#28 6 years ago

Well that just sucks. Display PIA above that explains the display issue.

Let me know if you want help.

viperrwk

#29 6 years ago

I will hit it with vinegar and reflow/retin everything and see what happens. Worse case I pick up a rottendog in Allentown at a show price. Probably not a bad idea period to get a rottendog.

#30 6 years ago
Quoted from Whridlsoncestood:

I will hit it with vinegar and reflow/retin everything and see what happens. Worse case I pick up a rottendog in Allentown at a show price. Probably not a bad idea period to get a rottendog.

Just get it fixed!! We Allentown pinball crazy heads have no tolerance for a machine working half assed....nobody likes to watch things "warm up"

My TFTC was doing the same thing and it was driving me bonkers......plus it started getting worse so I had it all fixed up for and in tip too shape. I'm feelin' for ya!

#31 6 years ago
Quoted from Whridlsoncestood:

I will hit it with vinegar and reflow/retin everything and see what happens. Worse case I pick up a rottendog in Allentown at a show price. Probably not a bad idea period to get a rottendog.

You can neutralize the acid with vinegar, but reflowing everything is almost certainly a waste of time. Electromigration can get corrosion into the component bodies. Some of those components may be in need of replacement. It's hard to say which, usually every component that has been exposed for a period of time gets replaced. When this happens on the old Ballys, I use Ed's kit from GPE to replace the entire reset section group of components. The vinegar wash process is just to neutralize acid so the board traces do not continue to get eaten away, it doesn't actually "fix" anything.

I'm sorry to be the bearer of bad news, but if you are leaning towards replacing it - then that would be the way to go. If you like spending a lot of time desoldering and replacing components, make a list of all those components in the pic and any others that look hit with corrosion, do the cleaning, and go to town. An easy Bally is a good 4 hour evening (for me) to do a thorough corrosion repair. I've never done a Sys 11, and avoid corroded boards when I buy them. Just my honest opinion.

#32 6 years ago

If the leads/legs have corrosion that touches the body, I consider that part toast and simply replace.

You can't clean the underside of the parts, thus you can't stop the corrosion.

My time is worth more than a few bucks on iffy parts.

#33 6 years ago
Quoted from Pinballerchef:

Just get it fixed!! We Allentown pinball crazy heads have no tolerance for a machine working half assed....nobody likes to watch things "warm up"
My TFTC was doing the same thing and it was driving me bonkers......plus it started getting worse so I had it all fixed up for and in tip too shape. I'm feelin' for ya!

Don't wory. Board will be repaired or replaced by Allentown. All will be fine. Game will also be in the tournament.

I will probably order the parts and work on it over a couple nights and have a backup if all goes well.

-Jim

#34 6 years ago

Put in a working system11 CPU. All is well. Rottendog replacement is being picked up Friday morning at Allentown.

-Jim

5 years later
#35 10 months ago

I had the exact same issue on my Space Station and it had me baffled. Turns out capacitor C58 in the blanking circuit on the MPU was bad. Freeze spray to the rescue!

I know this thread is old, but found it when looking for a solution. So for future reference...

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