Harlem Globetrotters- lost all computer controlled lights

Last night I went to play my HG for the first time in a couple months. The first game went fine and on the 2nd ball of my next game all of the computer controlled playfield and backbox lights quit working. I hit the self-test button once and nothing flashed like it should.

Today, I pulled up pin wiki and did a little digging. I went through some diagnostics per their guide and came up with the following results: 1.) all of the fuses are good on the rectifier board 2.) I have 5.3vdc at test point 1 on the light board 3.) I have continuity for ground on the lamp board on connector J4 pins 1,2, and 11.

At this point I'm not sure what else to look at. Anyone have any suggestions?

#2 4 years ago

AMR

BigAl56

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Palatine, IL

7y 64,800 1,659

Measure the voltage on the common braid of the switched lamps. Should be 6.3v DC. If that's good ground the tab of one of the switched lamps and see if it lights.

Your problem is either no 6.3v at the switched lamps or the lamp board select addressing and wiring is faulty. If you have the 6.3v and the lamp lights when grounding check the connector on the lamp board for loose wires or cold solder connections.

#3 4 years ago

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pindude80

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Quoted from BigAl56:
Measure the voltage on the common braid of the switched lamps. Should be 6.3v DC. If that's good ground the tab of one of the switched lamps and see if it lights.
Your problem is either no 6.3v at the switched lamps or the lamp board select addressing and wiring is faulty. If you have the 6.3v and the lamp lights when grounding check the connector on the lamp board for loose wires or cold solder connections.

BigAl56, thanks for the reply! I forgot to add in my original post that I checked the ground braid for the control lights and don't have any voltage.

#4 4 years ago

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FatPanda

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check voltage at TP1 on your rectifier board. should be around 5.4V.

#5 4 years ago

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pindude80

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Quoted from FatPanda:
check voltage at TP1 on your rectifier board. should be around 5.4V.

Might be onto something here, no voltage at TP1 on rectifier board.

#6 4 years ago

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FatPanda

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OP
Quoted from pindude80:
Might be onto something here, no voltage at TP1 on rectifier board.

That means BR1 is likely bad. I would replace the bridge rectifier or replace the board with a Weebly board if it's in any condition other than good. They're cheap enough at $35 for the kit or $55 assembled, shipped.

#7 4 years ago

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pindude80

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Quoted from FatPanda:
That means BR1 is likely bad. I would replace the bridge rectifier or replace the board with a Weebly board if it's in any condition other than good. They're cheap enough at $35 for the kit or $55 assembled, shipped.

After seeing no voltage on TP1 I got to thinking that a bridge probably went bad also. My buddy just did a full overhaul on the board less than a year ago and it worked great up until now. I will pull the board and see if I see a bad solder joint or something like that. I looked around on pinwiki on how to test the bridges on the rectifier board but didn't see any tests so I'll google around to see if i can find something.

#8 4 years ago

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FatPanda

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Quoted from pindude80:
After seeing no voltage on TP1 I got to thinking that a bridge probably went bad also. My buddy just did a full overhaul on the board less than a year ago and it worked great up until now. I will pull the board and see if I see a bad solder joint or something like that. I looked around on pinwiki on how to test the bridges on the rectifier board but didn't see any tests so I'll google around to see if i can find something.

If he didnt replace the bridges, they might have just gone bad. That's what they do, they will work one day, then not work the next.

Apparently you can test them in diode mode with the game off. I would imagine if it was working, you would get a reading in one direction but not in the other direction. If you get the same reading in both directions, it's bad. I've not had to test one myself, so just going off of how I've tested other diodes.

#9 4 years ago

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Chisel

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6y 49,800 306 1

In diode mode, Put the black lead of your DMM On the + leg of the bridge (upper left). Put the red lead on each of the ac legs (upper right and lower left). Each should read around 500 or so. Next do the same but with red lead on - leg (bottom right). You should get around 500 again.

#10 4 years ago

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pindude80

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I bought a rebuild kit from Big Daddy that included all of the bridges. He installed all of the bridges as well as the rest of the components in the kit. I tested the bridges last night and sure enough BR1 is bad. I don't remember having any problems with BR1 before the rebuild so I'm hoping it failed because it's a cheap chinese part and that something in the game didn't cause the bridge to fail. I'm going to get a replacement, install it and see what happens!

Thanks to everyone for the helpful posts!

#11 4 years ago

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BigAl56

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Palatine, IL

7y 64,800 1,659

The bridge needs to be heat sinked otherwise it will overheat and die. The original bridge was screwed to the chassis of the transformer assembly. New replacement boards mount their bridges on the front of the board and must have a suitable heat sink attached. If the heat sink and corespondin thermal compound is omitted the bridge will burn out and fail prematurely.

#12 4 years ago

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FatPanda

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Quoted from pindude80:
I bought a rebuild kit from Big Daddy that included all of the bridges. He installed all of the bridges as well as the rest of the components in the kit. I tested the bridges last night and sure enough BR1 is bad. I don't remember having any problems with BR1 before the rebuild so I'm hoping it failed because it's a cheap chinese part and that something in the game didn't cause the bridge to fail. I'm going to get a replacement, install it and see what happens!
Thanks to everyone for the helpful posts!

I would spend the $35 for the kit from Weebly. The heatsinks on the bridges are hefty and the traces are huge. You won't have to worry about changing that board out for at least another 40 yrs.

#13 4 years ago

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pindude80

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Quoted from BigAl56:
The bridge needs to be heat sinked otherwise it will overheat and die. The original bridge was screwed to the chassis of the transformer assembly. New replacement boards mount their bridges on the front of the board and must have a suitable heat sink attached. If the heat sink and corespondin thermal compound is omitted the bridge will burn out and fail prematurely.

It had a heat sink on it and thermal compound. I got a bridge from my friend and will be installing the heat sink again with the thermal compound.

#14 4 years ago

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pindude80

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Quoted from FatPanda:
I would spend the $35 for the kit from Weebly. The heatsinks on the bridges are hefty and the traces are huge. You won't have to worry about changing that board out for at least another 40 yrs.

I got a replacement bridge from my friend. I'm going to install it since it won't take long and if the board takes a dump again I will probably do as you suggested.

#15 4 years ago

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pindude80

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I replaced BR1 last night and I have over 5vdc at TP1 again on the rectifier board and the control lights are working again. I played a few games, no issues. I left the game on in attract mode for about an hour and the control lights were still on. I hope it was just a flaky bridge, knock on wood, but time will tell I guess.

Thanks again for the info guys and helping me get this narrowed down and fixed!

#16 4 years ago

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FatPanda

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OP
Quoted from pindude80:
I replaced BR1 last night and I have over 5vdc at TP1 again on the rectifier board and the control lights are working again. I played a few games, no issues. I left the game on in attract mode for about an hour and the control lights were still on. I hope it was just a flaky bridge, knock on wood, but time will tell I guess.
Thanks again for the info guys and helping me get this narrowed down and fixed!

Glad it's working! There are heat issues on those bridges, so I wouldnt be surprised if it goes bad on you again in time. For long term reliability, I'd get a Weebly board and not have to worry about it again.

#17 4 years ago

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pindude80

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Quoted from FatPanda:
Glad it's working! There are heat issues on those bridges, so I wouldnt be surprised if it goes bad on you again in time. For long term reliability, I'd get a Weebly board and not have to worry about it again.

Thanks I just hope it stays working. I installed the upgraded bridge that pinwiki calls for. Just for my knowledge, do they have heat issues also or are you referring to the factory bridge types? If it goes out again I will much more than likely go the weebly route.

#18 4 years ago

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FatPanda

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Quoted from pindude80:
Thanks I just hope it stays working. I installed the upgraded bridge that pinwiki calls for. Just for my knowledge, do they have heat issues also or are you referring to the factory bridge types? If it goes out again I will much more than likely go the weebly route.

I'm pretty sure any Bally that I've owned got a new Weebly board because the original Bally board had one issue or other. I'm not sure about the different bridge types to be honest. Again, the new boards are so inexpensive that it doesnt take much for me to replace the old ones.

#19 4 years ago

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slochar

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7y 86,550 6,917

The original bridge that was heat sunk was 8 amp so the theory is that the 35 amp bridge 'shouldn't' need it, since the max drawn out of it shouldn't exceed the 8 amp, but heat sinks are cheap so why not slap it on there? The only one that doesn't need it is the solenoid bridge since it's not continuous draw.

#20 4 years ago

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pindude80

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Quoted from slochar:
The original bridge that was heat sunk was 8 amp so the theory is that the 35 amp bridge 'shouldn't' need it, since the max drawn out of it shouldn't exceed the 8 amp, but heat sinks are cheap so why not slap it on there? The only one that doesn't need it is the solenoid bridge since it's not continuous draw.

Bridges are installed with thermal compound on all bridges so hopefully that helps!

#21 4 years ago

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Quench

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8y 114K 8,041

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Quoted from pindude80:
Bridges are installed with thermal compound on all bridges so hopefully that helps!

Pictures?

Are you using LEDs or incandescents?

#22 4 years ago

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BigAl56

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Palatine, IL

7y 64,800 1,659

Quoted from slochar:
The original bridge that was heat sunk was 8 amp so the theory is that the 35 amp bridge 'shouldn't' need it, since the max drawn out of it shouldn't exceed the 8 amp, but heat sinks are cheap so why not slap it on there? The only one that doesn't need it is the solenoid bridge since it's not continuous draw.

Intimately familiar with this. According to the manufacturer datasheet, the bridge amperage capacity declines per temperature. To achieve the maximum rated amperage you must heat sink. Original Bally bridges were smaller and capable of dissipating less heat per ambient temperature in the backbox. They were sinked to the chassis of the rectifier assembly. That sinking was often insufficient and the bridges often failed prematurely.
The newer rectifier board design Doug MacDonald and I came up with used larger bridges with a lesser sinking requirement and we sinked them to the chassis anyway making that board bulletproof. Modern bridge rectifiers can dissipate more heat but the switched illumination can still burn the bridge out if it's not sufficiently heat sinked. When in doub,t would-be engineers should check the datasheet and measure the temp with a thermometer. (Or just over-engineer it like we finally did. )

#23 4 years ago

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pindude80

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Quoted from Quench:
Pictures?
Are you using LEDs or incandescents?

Everything is LED'd. Below is a picture of the board and bridges with heat sinks.

IMG_20200406_141717_DRO[1] (resized).jpg

#24 4 years ago

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Atari_Daze

Spd

Houston, TX

7y 141K 10,053 7

May be unrelated, is this a broken jumper?

pasted_image (resized).png

#25 4 years ago

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pindude80

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Quoted from Atari_Daze:
May be unrelated, is this a broken jumper?[quoted image]

I'm not sure what it is but I will take a look.

#26 4 years ago

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Quench

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8y 114K 8,041

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Quoted from pindude80:
Everything is LED'd

If you're running LEDs in the feature lamps you shouldn't be blowing bridges. LEDs draw much less current than incandescents. If it dies again there could be another issue.

#27 4 years ago

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pindude80

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Quoted from Atari_Daze:
May be unrelated, is this a broken jumper?[quoted image]

Wow, you have a good eye! I took a look at it and the jumper is wrapped from the backside and it appeared intact but I got the DMM out to confirm I had a connection, and I did.

#28 4 years ago

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pindude80

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Quoted from Quench:
If you're running LEDs in the feature lamps you shouldn't be blowing bridges. LEDs draw much less current than incandescents. If it dies again there could be another issue.

I think this is the first bridge it's blown; I know I never lost the feature lights before. Hopefully it doesn't blow again but if it does I agree it's more than likely something else and I will have to look for a reason why.

#29 4 years ago

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pindude80

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