What is the best and quickest way to determine the value of the needed resistor.?

Interesting, I didn't expect that.
The Display refresh Interrupt has precedence over the Zero Crossing Interrupt so could be affecting the timing of when the Zero Crossing Interrupt is serviced since the CPU is much more busier running at slower speed.

The lamp refresh code between Ali and Flight 2K is the same. The lamp test mode code is slightly different though - looks like Flight 2K has some extra delays.

If you can be bothered, try swapping Q2 with another SCR on the LDB and see if the flickering follows the SCR incase it's a tolerance thing on that Q2 SCRs holding current.

The lamp flickers in game play mode too with just ali... odd.

swapping the Q2 with another is a fix as lowering the load R value. Seems every SCR is not created equally. I have just a few from both On Semi and UTC brands not latching 680R in ali. Easiest and best fix might be to just use 560 or 470R even if it is overkill in most situations. Start getting close to the 1/8w rating of the sip networks in later games using the -54 transformer that run the feature lamps as much as 7v.

Newest MPUs changed R21 to a 27K resistor + 10k trim pot wired up like a rheostat which allows the display interrupt to set to about 300 - 400hz. I might try twizzling that pot to see if it effects the random SCR LED flicker in Ali.

Yes, that seems to be the case.
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I only have LEDs (cheap generic 10mm) in one of my games. The LEDs have 470 ohm resistors internally across them and work fine in game mode but a few flicker in lamp test mode. I even tried putting 220 ohm resistors on some of these flickering LEDs but it didn't cure all of them. This game is a Bally with heavily modified code including modified display code so the CPU is rather "busy".
I suspect if you adjust the display interrupt frequency on your new MPU board it will affect the LED flickering.

I recently installed some of these Siegecraft anti-flicker LED boards (which uses 750 ohm resistors) into a Xenon and they worked flawlessly.

Down to 4 pieces of the current run, which has the typo I've been having to re-sticker. Updated version should be available in a week or two.

Assuming there's no more marking errors, or anything new comes along forcing a design change, I'm hoping there will be no further updates in future versions. It's quite a mature design at this point. After some initial flubs way back in the beginning, it's been a LONG time since anybody has come across a game with fitment issues.

I'm hoping the absurdly busy summer will start giving me some room to breath in the near future here so I can start working on some packaging improvements and a version for Gold Ball.

-Hans

Wanted to order from comet but out of
stock. Any idea when they might get some
more. Thx.

Tracking showed the box in Denver this morning, so if not Today, it’ll be Monday.

Just did this on my Paragon, and it works GREAT! Newark was selling the SIP networks for $0.12 each so I bought a bunch. I put mostly Comet warm white retro SMDs in, only color matching the green and red, and so far, it’s looking awesome. All in, it’s about $35 plus a couple hours of time.

Not as slick or versatile as the Siegecraft solution, but I’m a DIY guy, whenever possible.
Jeff

I have to say, I love you guys. I can't tell you how appreciative I am. Why do I say this so openly? Because sales are strong and GROWING on these still, after 4 years, and I'm estimating 2,000 sets sold at this point. I've had a few hiccups here and there, but you all have been very patient with me, and I've done my best to keep making this product better with every iteration. Latest change is a bit of a packaging update to eliminate the plastic baggies, replaced with a cardboard divider. Same cost per kit but a lot faster to pack. Next change will probably be a sealer for the clamshell boxes I use on the auxiliary kits, they pop open too easy. But the design right now I think is pretty darn solid.

Just boxing up another order today, and on a random thought I did some internet digging. I was able to find 4 other places now selling their own version of this adapter. But people keep buying mine in big numbers. That speaks a lot, and it's humbling.

So I just wanted to get in here and thank you all for everything.

-Hans

Hi Hans

I am interested in buying a couple of sets of these. Are they still available in kit form or only as complete sets?

I don't advertise the 'builders kits' anymore, which was all the resistors installed but no connectors included.
But right now I have plenty of boards on hand and can sell a few that way for you.
Those are priced at $15 per 'set'

-Hans

Thanks Hans. Will send you a PM.

Making a 'product change notice' on these.

With all the tariff's and such, I'm doing what I can to NOT raise prices at all. So I'm going to be eliminating the little test point clips on each board. The pad will still be there for you to test voltage, but the loop won't be there any more to clip on a test lead. (Unless a bunch of people tell me how awesome the test points are, then I can add them back on, but need to keep the business running too).

Probably be a bit before anybody see's the change, I have about 40 or so boards on-hand that already have them installed. But once I run out I won't be ordering more of the test points.

Also going to be changing suppliers on the header connectors. Found a different source for them with the same length and size, but with gold flash on the mating pin, at a non-molex price.

I may have missed it in the thread, but it appears that the SCRs that are affected are primarily 2N5060. This component has a 5mA holding current,and we know that's too high for LEDs. I see that a lot of work has been done to increase current draw with resistors - I'm a happy SiegeCraft customer - but it strikes me that we haven't tried using different SCRs. BT169 is a higher-rated drop-in replacement for the 2N5060, costs half of the original component, and has a holding current of only 1mA.

Has anyone tried using BT169 SCRs? This seems to be an inexpensive solution that will allow the lowest possible current draw.

Would this still work if you switched back to a regular bulb for some reason?

I have a working lamp driver I could experiment with if anyone was interested.

The minimum current draw for the cheapest LEDs is about 20ma - SMD LEDs can draw 60ma per chip. The problem is that when the lamps are being switched on in these classic Bally/Sterns, it's happening during the rise of the rippling DC voltage and at that moment the voltage is not high enough to draw enough current through the LED for the SCR to latch on. Because it's happening during the voltage rise it typically affects the first lot of lamps that are being refreshed.

I've looked at two different BT169 SCR datasheets and they both say maximum (worst case scenario) holding current is 5ma which is the same as 2N5060. Where did you see 1ma specification?
MCR100 SCRs are plugin cheaper replacement for 2N5060.

I have noticed the latching current requirement of SCRs is all over the place, even in the name brand parts like on semi it varies lot to lot and even piece to piece. I tested four different brands/part numbers and go figure the cheapest Chinese brand from LCSC has the best latching characteristics out of all the ones I tested. I had one lot of on semi SCRs that wouldnt latch for crap with LEDs unless i really stiffened up the resistors to about 270R-330R. Still was fine for incandescent.

https://datasheet.lcsc.com/szlcsc/1810010233_Changjiang-Electronics-Tech-CJ-MCR100-6_C77884.pdf

I assume the means the original lamp boards are also going to show some variance on latching current and whether or not you get full latching with an add on board.

Once I run out of the current PCB layout I believe am switching the lamp board to use all C106 SCRs and no TO92 packaged ones. The larger packaged C106 SCR seem to have better latching characteristics even tho the data sheet says it shouldn't.

For stern MPU200 games the lowest decoder positions you need about 470ohm load resistor @6v or else you have a good chance some LEDs will not latch the SCRs. For Bally -35 games its about 680ohm on the lowest decoder positions.

Also minor differences in CPU board clock speed will effect latching characteristics too. Its why MPU200 games will always be more likely to have flickering LEDs than Bally games. The faster the CPU clock, the closer they update the feature lamps to zero volts and not enough current flows to latch the SCR.

Hell, I have one of your new lamp driver boards, and I have a few SCRs on IT that just won't stay latched with LEDs. (Never complained because luckily they're in lights that are rarely lit.)
But, yeah, I've seen variance (even with the Seigecraft (sp? adapters) on original boards.

Add an extra 1k resistor across the offending lamp or do it at the LDB and it should fix. The RL resistor designation number line up with the SCR's designation number. I can swap out the LDB if you want to.

A few months ago I changed my test fixture to try and mimic worst possible case scenario to identify any SCRs that don't want to latch and then tweak that SCR's load resistor value or replace the SCR.

Will do!

Appreciated, but no need. I wouldn't feel right for putting you up to all that loss for something I've been living with for .. hell a year? two?.. I've lived this long, i can be happy with a small fix.

More I was just commenting on the apparent huge range of these suckers out there.

It was on a component listed by Digikey, but that said, yeah, these components land all over the map and this usage case is on the margins of their operating range.

I admit this is not a problem that needs an additional solution; the one we have already works fine.

A lot of it is also ability and cost levels too. Swapping out all the SCR's on a lamp board is a lot of work, with some risk of damage, particularly if you're inexperienced with rework.

With a new lamp board, there is the potential for using different SCR's, but I haven't looked into it since there are already a few lamp boards on the market. However there is the cost difference between adapters and full lamp driver boards.

another way to do it may be to intercept the lamp address/data/strobe and delay it to be further from the zero crossing point. shift registers and a clock or something like that.

the aux lamp board never flickers with LEDs because it is refreshed after the main lamp board putting it further from the zero cross point.

Cheers, ok I see the SCR you're talking about - it's the "-L" version of the BT169, i.e. "BT169-L"

If you're willing, give them a try.
The SCRs on the lamp boards that will probably be most susceptible to flickering are at Q14, Q29, *Q33, and *Q47 (* these last two are the larger MCR-106 SCRs). These are the first SCRs that are switched on when the lamp voltage level is at its lowest. Before wholesale changing all the small SCRs, just replace Q14 and Q29 first.

Ignore this one, put it in the wrong thread.

Old post but I had to follow up: having done individual resistors on sockets and these handy adapter boards I thought I'd give adding SIP resistors to the driver board a go this time around.

Sweet mod which will now be my go to for Ballys. Love it!
20210228_154933 (resized).jpg

I've got a anti flicker board problem. Any help is appreciated. I have anti flicker boards installed in my game (Seawitch) and they make a world of difference. Currently I have them attached to my controlled lamp wire on the backside of my backbox light board. All the controlled lamps share the same power source. When the wire for the anti flicker board is attached I loose the last light in the chain which happens to be "high score to date". It works fine when the alligator clip is removed. The line isn't long enough for me to try attaching it under the playfield. I was going to lengthen it tomorrow and see if a different power source is better. Anyway, I thought is was kind of odd. Anybody have a fix for this?

Fixed my own problem. It was a bad trace going to the middle pin of Q16. "High score to date" now works with the anti flicker kit installed.

Thank you vid, this has helped me now two times with an old Galaxy and Bally Kiss!

Using this again with eight ball deluxe! this thread FTW!