LED light problem.

jkoolpe

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Hey all!

I picked up a bunch of the newer style LED lights for my ST:TNG pin this past weekend as I saw them on display in another ST:TNG and they looked great.

However, I have a problem with some of them. Most work fine, but a few of the lights stay lit most if not all of the time rather than blink as they are supposed to :( .

For instance, the Starfleet symbol just under the "Mission Start" hole and the "Asteroid Threat" lights stay lit even when they are not supposed to be. All of the other lamps when replaced with LEDs in the Mission description circles (that inhabit the circumference of the Enterprise on the playfield) blink on and off as they are supposed to. I cycled through the individual lamp test, and very often these lights would come on in conjunction with another as I pressed through to test each lamp separately.

The regular incandescent bulbs still work fine.

I have the L7 ROM version.

Anyone else have this problem with these types of lamps and/or know what to do to fix this problem?

Thanks,

Jon
 
From what I know that's a known problem with LED's. A little bit of power 'bleeds' back and because the LED needs so little power it causes it to light a little bit. Not sure if there's a fix at all.

Some games and some spots in certain games work fine..others games or spots don't work fine.
 
Unfortunately the short answer is that pinball machines were not designed to use LEDs so there are many cases where they simply don't work as you would expect.
 
Unfortunately the short answer is that pinball machines were not designed to use LEDs so there are many cases where they simply don't work as you would expect.

Which is something I was afraid of, and why I ended up sticking with incandescent bulbs when I replaced the two dozen or so that were out on my Frankenpin.

I was also worried that the light shows wouldn't be as good since LEDs can't fade in or out.

I'm quite happy with the olde-tyme bulbs, and you really can't beat their cost.
 
I actually kind of have the opposite problem to Jon. I popped in a couple of LEDs just as an experiment in my Space Shuttle's "extra ball" and "special" inserts, and where the incandescents would stay solid when those lamps were lit, the LED's flash rapidly. Anyone with a Space Shuttle notice if your extra ball and special lamps flash or stay solid?
 
Some game work better with LEDs than others. My Who Dunnit is awesome with LEDs. They're only on when they're supposed to. It's in the programming. For instance, I understand that TZ's home roms work well with LEDs, but some other versions show this ghosting you're talking about. At least that's what I hear. I was dying to put LEDs in my STTNG, but the ghosting in that game is terrible... so, I just left it as is (sadly).
 
It would seem to me you would only use them in GI circuits and not controlled lamp positions.
 
the LED's flash rapidly. Anyone with a Space Shuttle notice if your extra ball and special lamps flash or stay solid?

That's a typical result as well. Remember that the feature lights (insert lights) are controlled by a lamp matrix. The matrix scheme "strobes" the lamps. Due to the soft off nature of normal light bulbs (the heated bulb filiment continues to glow for a brief time after power is removed with the light output ramping down as the filament cools), you don't see the strobing. With LED's you can see the strobing of the matrix since they turn off very quickly.

That's another one of the drawbacks of LED's. In some machines you will see the strobe effect, in others LED's will seem to flicker. It can be very distracting during game play as you will keep catching a flicker or flash in the corner of your eye.


I have not experimented at all, so use these ideas at your own risk, But for LED's that remain on when they should not be on, you can try adding a bleeder resistor across the lamp terminals to bleed off any leakage current that may be present and holding the LED on. You'll want a low enough resistor to shunt the current but high enought that it doesn't draw significant current, and overload the driver circuit, when the lamp is on.

For LED's that flicker or strobe, you can try adding a small cap across the lamp terminals. Acting somewhat as a filter, it may smooth out the stobe pulses and also provide a look more similar to light bulbs. During "off time" of the strobe, the cap will discharge thru the LED. As the cap discharges and it's voltage drops the LED should "glow out" instead of just turning off. You'll want the cap large enough to provide the desired effect but not so large the inrush current is excessive and could damage the driver.

You'll have to work out some starting values for caps/resistors. I'll try to do it later myself because now I am curious myself.

Be sure anything you try is after the lamp diode so it doesn't effect the entire row or column.


D
 
I have not had mine 3-led's do that even when I had them in for G.I., but I didn't like the look and switched them to the inserts and put incandescents bulbs in G.I. and other location. On my HS I put LED's in the traffic light and the Jet (pop)-bumpers. But I can't use flashers that are LED's I found this out by asking Bruce at B.C. LED he said other retailers on the internet selling wont tell you that Data-East and ALL system 11 machines like Space shuttle and High Speed will burn out prematurely, you see the flashers are #89 and system 11 an D.E. machines call for #63. Bruce is getting #63 bulbs (flashers) for our machines, should be a week or two. Then I will outfit all flashers with LED's but everything else regular warm glow incandescents. Have not experienced anything like above mentioned.
 
Which is something I was afraid of, and why I ended up sticking with incandescent bulbs when I replaced the two dozen or so that were out on my Frankenpin.

I was also worried that the light shows wouldn't be as good since LEDs can't fade in or out.

I'm quite happy with the olde-tyme bulbs, and you really can't beat their cost.

Should have put them in your pop-bumpers or any hard to get to places. There be no problems if you only put them there. You would never have to pull off ramps, etc. for years to change bulbs.
 
It would seem to me you would only use them in GI circuits and not controlled lamp positions.

People have found the more direct, beam-like nature of the LEDs don't do well in GI spots where you just want to light up an entire area. They seem to be more suited to inserts, where your just lighting a small spot.

That's a typical result as well. <snip>

For LED's that flicker or strobe, you can try adding a small cap across the lamp terminals. Acting somewhat as a filter, it may smooth out the stobe pulses and also provide a look more similar to light bulbs. During "off time" of the strobe, the cap will discharge thru the LED. As the cap discharges and it's voltage drops the LED should "glow out" instead of just turning off. You'll want the cap large enough to provide the desired effect but not so large the inrush current is excessive and could damage the driver.

You'll have to work out some starting values for caps/resistors. I'll try to do it later myself because now I am curious myself.

Be sure anything you try is after the lamp diode so it doesn't effect the entire row or column.


D

Great idea, if you come up with values, please post them. Maybe this will do the trick.

FWIW Steelhorse, Space Shuttle is a System 9 game. Doesn't matter, generally what applies for system 11 is probably true for system 9 anyway, but just in case you ever ran into a discrepancy - that would be why.
 
I messed around a bit more with my ST:TNG last night...put LEDs in the bonus multiplier slots (2X, 4X, etc.). All worked fine except for the "10X" in the series which stayed lit. Put 3 in the green upper slots that increase the bonus multiplier, and they all worked fine.

I pulled out the "Asteroids Threat" and "Start Mission" ones and returned them to incandescents. I did notice that even with the incandescent, the "Start Mission" had some residual light on (very weak) when it was supposed to be off, and also still tended to flicker slightly. Maybe the diode at that light terminal is failing? Should I replace?

I also pulled the "Mission Select/Description" board and re-soldered many of the points, some of which did appear to be developing cracks. Didn't solve the "Asteroids Threat" LED "stuck on" problem....

I put in LEDs on all of the blue "shield" lights also. For those, they looked great when the game is on but not being played. But the moment you begin a game, they all dim a bit and develop a flicker. I can probably live with it, but I'm wondering if there is anything else I can do to prevent this (or is it just normal)? Install a switching power supply maybe for smoother power flow?

Finally, I put a couple of extra LEDs I had in my Twilight Zone, and they all worked straight up and look great :) . Put one of them in the "?" that indicates entry into "The Zone"...that looks very cool now I must say... ;)
 
I put in LEDs on all of the blue "shield" lights also. For those, they looked great when the game is on but not being played. But the moment you begin a game, they all dim a bit and develop a flicker.


If I recall, the shield lights dimming are intentional and that's an element of the game design. The flicker results from the way in which the dimming is accomplished. To dim the shield lights, or any GI for that matter, WPC based games pulse width modulate the GI triacs. At lower rates the LEDs will flicker due to this PWM control. It's noticed more with LEDs than typical light bulbs again due to the instant on/off nature of LEDs as opposed to soft on/soft off nature of bulbs.

D
 
Good luck with that! What kind of LED? I should say where did you buy the LED's? Terry at Pinballlife.com has told me that LED do act funny sometimes in different machines then other machines, he has the Ablaze 3-LED's I have these in my inserts and have to say honestly are way better then reg. bulbs inserts that is. Pop-bumper and traffic light led's were bought from Bruce at BC Led's another great company to deal with my opinion they both have answered my questions and I recommend you as well to call the company and talk to them. I have not experienced that problem you describe with any of the LED. Also it a good idea to call and ask questions before making a purchase, make sure there compatible with your system and the type of application your doing. Enjoy.
 
I also pulled the "Mission Select/Description" board and re-soldered many of the points, some of which did appear to be developing cracks. Didn't solve the "Asteroids Threat" LED "stuck on" problem....

Dude, did you even read my response?
 
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