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Why do LEDs stay dimly lit

biglouieuk

biglouieuk

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Joined
Dec 22, 2019
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565
Location
Kent
Alias
robllewellynuk
I've had a read of course, and as I understand it, the LED needs a very small current. Older machines were not so efficient in some way, so power that would NOT light an incandescent bulb, will slightly light an LED?

I just stuck 3 new pop bumper LED rings in. I installed the lamps and attached to the lamp matrix, new diodes, new lamp holders etc. 2 stay dimly lit, 1 goes completely off.

Is it somehow related to the column or row they are on? If that "line" is not very well "closed off"?

Sorry for n00b terminology, I was just watching the lights (bit mad) and I wondered why it happened. My LEDs are not the non-ghosting type presumably!

Just interested.. :)

Rob
 
Your research has covered it basicallly. Incandescent lamps are given a bit of voltage to “pre-warm” them and this is what causes leds to ghost/light up when you don’t expect as they don’t need it. From what I understand it’s to do with the reponsivness of the lamps switching on and off. LEDs are basically instant on/off from 0v where as incandescent lamps aren’t
 
ronsplooter said:
Your research has covered it basicallly. Incandescent lamps are given a bit of voltage to “pre-warm” them and this is what causes leds to ghost/light up when you don’t expect as they don’t need it. From what I understand it’s to do with the reponsivness of the lamps switching on and off. LEDs are basically instant on/off from 0v where as incandescent lamps aren’t
Click to expand...
Isnt there rom updates for many games to cure that?
 
AlanJ said:
Sounds like they are ghosting! Are you sure you bought non-ghosting ones.
Click to expand...
Hey Alan. I don't think I did, Super Brights from pinball-leds.co.uk

But that's fine, I just wondered why they did it and why some did and some didn't and if there was any relationship between them.
 
ronsplooter said:
Your research has covered it basicallly. Incandescent lamps are given a bit of voltage to “pre-warm” them and this is what causes leds to ghost/light up when you don’t expect as they don’t need it. From what I understand it’s to do with the reponsivness of the lamps switching on and off. LEDs are basically instant on/off from 0v where as incandescent lamps aren’t
Click to expand...
Thx Ron. I was trying to think (as I mentioned to Alan above) why they don't all ghost.
 
it could be your lamp driver board, the leds themselves, swap the leds around. swap the wires on the feeds to pops around. does the problem move?

not sure on williams but on bally’s the lamp driver board needs mods to make leds work properly. or you replace with modern lamp driver that supports leds

for later machines led ocd boards usually sort this. again it might be your solution

a small leakage on the driver board transistors can cause it so replacement with better spec parts might solve it


Sent from my iPhone using Tapatalk
 
I did a little testing, because - nerd. If you go through the Single Lamp Test and record what other lamps flash dimly on each... you find, that in 82.3% of cases (haha true story) the dimly lit bulb is in the column BEFORE the lamp selected but same row, in the Lamp Matrix. It's not all cases. A few of the dimly lits are the same column (in the case of the Mouth, all on the same light PCB perhaps), a couple are the column to the right, for no apparent reason.

For example, All Scores 2x is Column 7 in the Lamp Matrix, and the dimly flashing 50k is in Column 6 and same row.

SelectedAlso Dimly flashingRelationship
All Scores 2x50kDimly lit is 1 column to the left of selected
All Scores 3x100kDimly lit is 1 column to the left of selected
All scores 5x200kDimly lit is 1 column to the left of selected
StartMouth1 column right (8 to 1)
MouthAll of FaceSame Column
Drop 2Left outlaneDimly lit is 1 column to the left of selected
Drop 3Left Ball ReturnDimly lit is 1 column to the left of selected
PBonus 2xDimly lit is 1 column to the left of selected
ABonus 3xDimly lit is 1 column to the left of selected
LBonus 4xDimly lit is 1 column to the left of selected
ABonus 5xDimly lit is 1 column to the left of selected
CBonus 6xDimly lit is 1 column to the left of selected
EDrop 11 column leftDimly lit is 1 column to the left of selected

UPDATE from the future: By updating the game code (see below) this issue is fixed. But you will see lower down, the code does not fix a slightly different LED issue, where 4 rows seem to be dimly lit, when the field is meant to be dark, when the Hurricane wheel is spinning in the head on Mystery. (I hope this helps someone in the future!)
 
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And this game (Hurricane) version L-2, doesn't have updated Williams lamp matrix driver code.

"Since releasing the first patcher program, a total of 4 variations of the lamp matrix driver code have been discovered
The additional 3 versions of the driver code appear to apply to game ROMs released before the
2nd half of 1992.
Games with this early driver code include but are not limited to HD L-3, Hurricane L-2, PZ F-4,
BoP L-6, FT L-5."

I don't think updating game ROM code with the updates is for me! ...

Gratifying to test and identify the previous column issue and then read up on it in the article. Logic is logical..
 
I had a chat with John Honeycutt over email last night, he wrote a patcher for Williams games and is the author of the document linked above. wpclp.exe patcher is what you need to search for but you can find at github (haven't downloaded yet) HERE. I am sure anyone interested in this is already aware, but I'll leave it here incase.

I'll see if I can get Hurricane patched for LEDs and burn a new ROM. I'll need to either pull L-2 off my ROM or maybe find it a good version online like this? https://www.ipdb.org/machine.cgi?id=1257
 
biglouieuk said:
I had a chat with John Honeycutt over email last night, he wrote a patcher for Williams games and is the author of the document linked above. wpclp.exe patcher is what you need to search for but you can find at github (haven't downloaded yet) HERE. I am sure anyone interested in this is already aware, but I'll leave it here incase.

I'll see if I can get Hurricane patched for LEDs and burn a new ROM. I'll need to either pull L-2 off my ROM or maybe find it a good version online like this? https://www.ipdb.org/machine.cgi?id=1257
Click to expand...
All of my Williams have patched ROMs to deal with this. People on the forum can help with providing ROMs for you. It resolves the LED ghosting.
 
Update, incase anyone else needs/wants to do this to fix their LED ghosting at a ROM software level on Williams WPC machines.

On a windows machine
Download this ZIP - http://www.edcheung.com/album/album07/Pinball/wpclp_1.4.zip
Extract it.
Download your ROM file - Mine came from https://www.ipdb.org/machine.cgi?id=1257
Put your ROM file into the same directory/folder as the extracted ZIP above.
Have a read of the readme.txt, which gives you the command, wpclp {your ROM name.ROM}

Open Command Prompt and go to the directory wpclp_1.4 (it will probably be in your Download directory)
Type the command:> wpclp {your ROM name.ROM}

It will read your ROM.

It will say you need to give the new version a name. Read the readme.txt it tells you all about that. I used R-1 for mine

You're done. It will have created a new ROM called {your_rom_nameR-1.ROM}, send that to someone with a ROM burner, you (they) will need an EPROM M27C2001 or equivalent.

I haven't done the last bit yet, but its created a new ROM for me, so I will test it.
 
MartinY said:
All of my Williams have patched ROMs to deal with this. People on the forum can help with providing ROMs for you. It resolves the LED ghosting.
Click to expand...
Thanks Martin, appreciate the response. I spent this morning messing about with wpclp and have learnt a tonne of stuff.

I have a buddy on the case for the ROM burn now hopefully. Fingers crossed!
 
So while I wait for the ROM burnage, I was looking at how the lights pop up.

I notice when all lights are off and just DMD is doing something and back box is lit, a variety of bulbs come on dimly.

IMG_20201126_171843.jpg

I'm pretty sure this is meant to be a no playfield lamp situation. 😃

Which I presume will be different to the ghosting issue of the previous column lamp still being lit.

IMG_20201126_181440.jpg

Pink shows dimly lit when meant to be off.

Pattern? Rows. Special lamp only one and that was a maybe..

I'll move a few of the LEDs around, see if it's bulb related. All the same type and non-ghosting but rows seem likely!

Transistor perhaps or diode?
 
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Removed J133 & J138 because I thought this would somehow isolate the lamp matrix from the playfield.

Tested the transistors for Rows 1, 2, 6 & 7 (90, 89, 85 & 84) by setting DMM to Ohms, then doing left leg to right leg, then middle leg to left and middle leg to right. Dunno why I thought it could be that, but...

I tested the other rows, to see what was going on and I got similar results. So I guess not a transistor.

RowTransistorLeft Leg to Right LegLeft Leg to Middle LegMiddle Leg to Right Leg
Row 1Q908.745.935.77
Row 2Q898.586.276.28
Row 6Q859.235.746.07
Row 7Q848.776.136.10

Swapped a Comet LED in, still turns on with others.

As I installed the bumper jet lamps last week and they seem to be part of this, I think I'll take them out and see. I'm pretty sure this was happening before that but cant be certain.

I hope I tested right above.
 
Hi,
sorry for tagging onto this thread but I wondered where I can get an EPROM programmed ?
I’ve created the patched version using the software mentioned above but, as I’m no longer at work, I don’t have access to a programmer :(

Thanks
Paul
 
I've got the necessary stuff here. Waiting on eproms coming tomorrow, but depends what you need.

Happy to help if I can.
 
I popped the newly created ROM code onto a new chip, put it in the Hurricane and it worked a treat.

No lamps lit dimly in the background anywhere.

Magic.

I've tested Paul's ROM as well in my Hurricane and I see no lamps dimly lit there too.

Spectacular fix.. thank you for the links above, amazing to learn new skills and find out they work!
 
So, after a little bit of playtime... I notice the patch DOES fix the bulbs when the playfield is meant to be dark, mostly. In single lamp test, I get no ghosting on the lamps that were ghosting before. That makes sense to me, because all ghosting lamps were all in the previous column to the lamp on test, so the timing reason makes sense. LED comes on quicker than the incandescent bulbs, so it ghosts when flashing through.

However, Hurricane has a point when the Wheel in the head is spinning (to discover a Mystery!!!!) All the bulbs should be off, but I get ghosting on those same rows. Its in Post #20 above.

I'll tried the Extra delay

-e: extra-delay
Adds an additional 30uS of delay between clearing the row/column
and writing the new row/column values.
It may help with problem boards that still exhibit ghosting even
with the updated driver.

UPDATE: Extra delay doesn't work on Hurricane. I think because: "Games with this early driver code include but are not limited to HD L-3, Hurricane L-2, PZ F-4, BoP L-6, FT L-5."

Or maybe these rows of lights dimly on, when the Mystery wheel is spinning and the playfield is meant to be totally dark, is something else. Will try a few non-ghosting, see what occurs. But as its all lights in 4 specific rows.......
 
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From what i have seen, the standard settings are good enough for most. However on the odd occasion on specific machines, the standard settings arent sufficient... really is tral and error.
 
Paul said:
From what i have seen, the standard settings are good enough for most. However on the odd occasion on specific machines, the standard settings arent sufficient... really is tral and error.
Click to expand...
Thanks Paul. I hear what you are saying.

I'm investigating some wiring shenanigans as well... of my own making... :)
 
Let us know how you get on.

From what you say it doesn't seem to be ghosting if everything else in the matrix is off other than the 4 dim rows.
Although the program doesn't allow the delay to be extended it's definitely possible if required.

From reversing the Hurricane code I see an additional access to the lamp row driver which isn't part of the lamp mux update function. This bit of code hasn't had the CLR opcode replaced so if it gets called it'll certainly cause a glitch on the lamp row driver. Whether or not that's the problem I don't know.
If other investigations fail to reveal anything it could be patched and tried to see if it helps the issue.

You would've thought others with this game would've mentioned this problem.
 
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