I just picked up a NGG without testing it (it was a good deal from people who didn't know anything about pinball). Turning it on and blowing fuses 102 and 104 for solenoids and flashers.
Help me get this thing going. Not sure where to start as I've never worked on a WPC before.
Quoted from shirkle:Sorry...I just edited my original post. I listed the wrong fuse.
No problem do you have the manual for the game?
Diodes can be checked without pulling from the board, but F102 and F104 aren't fuses accociated with the diodes. Does LED105 light up?
Quoted from Ronkz650:Diodes can be checked without pulling from the board, but F102 and F104 aren't fuses accociated with the diodes. Does LED105 light up?
LED 105 is lit.
Quoted from bssbllr:That u5 chip looks like some corrosion as well as some of those resistors.
I'll be replacing those and adding in NVRAM. Don't have the chip for U5 on hand, so it'll be a few days before I can pull that one.
Quoted from shirkle:Both fuses still blew with their playfield connections removed (J113 for the solenoids 9-16 associated with fuse 102) (J109 for solenoids 25-28 associated with fuse 104).
Does this mean there is a board issue?
Yes, I would say so.
Quoted from shirkle:Transistor Q42 was bad. I replaced it and fuse 104 is all good. I can play a full game now.
No transistors tested bad from the fuse 102 bank, so I’m not sure what’s up there.
Even if it plays, you need to clean up the battery-damaged traces and components COMPLETELY or they will continue to eat the board, even if it plays right now.
Quoted from shirkle:I noticed that although I replaced the bad transistor (Q42- for the middle pop bumper) and the fuse is no longer blowing, the middle pop bumper still doesn’t work.
Would this likely be a bad diode associated with Q42?
Does it register in switch test?
Quoted from shirkle:No, it is not firing in test either.
Ok check the fuse again,i see on your previous post that you replaced it but pull it out and test with meter.If the fuse tests good then test the transistor that drives that bumper coil on the driver board.Also there's a pre drive transistor
Things to check
1.fuse
2.diodes on coil
3.coil resistance
4.main transistor on driver board
5.pre drive transistor on driver board(It's the one with a black tab with 3 legs
Quoted from pinmike:Ok check the fuse again,i see on your previous post that you replaced it but pull it out and test with meter.If the fuse tests good then test the transistor that drives that bumper coil on the driver board.Also there's a pre drive transistor
Things to check
1.fuse
2.diodes on coil
3.coil resistance
4.main transistor on driver board
5.pre drive transistor on driver board(It's the one with a black tab with 3 legs
1. Fuse is good. Just tested it out of circuit, plus the other coils associated with it are firing.
2. No diodes on coil- they're on the driver board for WPC 95 games....that's the diode I was asking about a couple posts ago. I have some on hand so I can try replacing it.
3. I'l have to read up on how to test coil resistance. I've never had to do that.
4. Replaced this a few days ago because it tested bad. Should be good now.
5. I can't figure out which one goes to this coil. Do you know?
Thanks for pointing me in the right direction!
Quoted from shirkle:3. I'l have to read up on how to test coil resistance. I've never had to do that.
This might help:
https://www.flippers.com/coil-resistance.html
http://www.pinballmedic.net/coil_chart.html
Quoted from shirkle:1. Fuse is good. Just tested it out of circuit, plus the other coils associated with it are firing.
2. No diodes on coil- they're on the driver board for WPC 95 games....that's the diode I was asking about a couple posts ago. I have some on hand so I can try replacing it.
3. I'l have to read up on how to test coil resistance. I've never had to do that.
4. Replaced this a few days ago because it tested bad. Should be good now.
5. I can't figure out which one goes to this coil. Do you know?
Thanks for pointing me in the right direction!
That's ok no need to test diode i forgot that WPC-95 has no diodes on coil,Do you have the manual?The manual will tell you which transistor on the driver board is for that pop bumper coil.
to test coil resistance you do NOT have to remove the coil or the wires on the coil lugs.To test coil resistance-Power off game
Set meter to ohms/lowest resistance setting.Then put the meters red and black probes on each coil's lugs, A resistance of 2 ohms or greater should be seen if not then there's something wrong
Quoted from shirkle:Looking thought the manual I was able to located the main transistor (Q42), but not the pre drive transistor that you mentioned. I replaced Q42.
I'll check coil resistance tomorrow- I didn't know it was that easy.
Ok when you post back your findings we will test the transistor.. 
When testing the coil, I got a reading of right around 2 ohms, but the other two coils for the other pop bumpers were around 12 ohms, which seems closer to what the links above referenced for this coil (AE 26-1200). Does that sound like the issue?
Quoted from shirkle:When testing the coil, I got a reading of right around 2 ohms, but the other two coils for the other pop bumpers were around 12 ohms, which seems closer to what the links above referenced for this coil (AE 26-1200). Does that sound like the issue?
No,On any coils a reading of 2ohms or higher is good
locate the the transistor on the driver board,the manual will help locating it.it will have the letter Q with 2 numbers
More info i just read your above post and you stated Q42 here's a quick test
To test transistor quick test 95% accurate-power off game!!
1.set meter on continuity setting
2.place black probe to ground(Gray strap in backbox)
3.touch the transistor tab with red probe
4.if the meter beeps when touching red probe to the tab of transistor it means that transistor has shorted/bad/faulty
Quoted from pinmike:locate the the transistor on the driver board,the manual will help locating it.it will have the letter Q with 2 numbers
More info i just read your above post and you stated Q42 here's a quick test
To test transistor quick test 95% accurate-power off game!!
1.set meter on continuity setting
2.place black probe to ground(Gray strap in backbox)
3.touch the transistor tab with red probe
4.if the meter beeps when touching red probe to the tab of transistor it means that transistor has shorted/bad/faulty
It passed this test. I ran the meter across the legs as well (black probe on metal tab, red on each outside leg) and got 0.4-0.6 on the legs, so I assume it's good.
I'll run the meter across the lugs of that coil again tomorrow and see how close to 2 Ohms it was. I believe it was over, but it might have been 1.7-1.9 or so. I'll doublecheck.
Quoted from shirkle:across the legs as well (black probe on metal tab, red on each outside leg) and got 0.4-0.6 on the legs, so I assume it's good.
To measure the transistor on the legs the meter would have to be in diode setting
Quoted from pinmike:To measure the transistor on the legs the meter would have to be in diode setting
It was. My cheapo meter doesn't have a continuity setting, so I set it to diode when testing for continuity as well. I figured since I was poking around in there, I might as well test the transistor itself.
Quoted from shirkle:It was. My cheapo meter doesn't have a continuity setting, so I set it to diode when testing for continuity as well. I figured since I was poking around in there, I might as well test the transistor itself.
Ok just making sure
Quoted from shirkle:1.8 ohms.
That's low it should be 2 ohms or higher
Quoted from shirkle:I’ll have to order one. Don’t have any of those around.
Would it hurt to swap it with one of the other pop bumper coils just to test it?
No it shouldn't hurt anything since the pop bumper coils are the same,go ahead give a shot and take some pics if you have to so you'll know how everything goes back especially the wires that are soldered on those coils.
On a side note, I replaced all of the components that were affected by the acid damage- two resistors, the74LS14N hex chip, a diode, and the batter pack (remote now). Maybe I’ll do NVRAM later.
I lost one solder pad that was pretty badly corroded, and added a jumper in its place. Not pretty, but it works.
It’s finally saving settings, which is good because I was getting tired of changing the language every time I turned it on.
Quoted from shirkle:It’s finally saving settings, which is good because I was getting tired of changing the language every time I turned it on.
That's good and yes that is a pain in the ass to keep changing it over and over.
Quoted from shirkle:Well, the new coil didn’t fix it.
ok let's test the pre-drive transistor it would be on the driver board,The location would be in the manual in the same spot of the main Q42 transistor.
the pre-drive transistor is a small black tab with 3 legs
Quoted from shirkle:Thanks. I’ll dig into it later. I don’t have a schematic, so I’ll try to trace it back. I believe the president-driver transistor is Q34, but I’ll check.
Ok
Wanna join the discussion? Please sign in to reply to this topic.
Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!
This page was printed from https://pinside.com/pinball/forum/topic/ngg-blowing-fuse-104?hl=djshakes and we tried optimising it for printing. Some page elements may have been deliberately hidden.
Scan the QR code on the left to jump to the URL this document was printed from.
Stephenson, VA
Berlin