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#7 Stern Lord of the Rings

Menace

Well-Known Member
Staff member
Nov 14, 2012
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Santiago de Aurora
So I'm supposed to be posting my repair adventures to this section but I have been slacking. Not due to lack of repairs, but more to do with the fact I keep forgetting to take pictures of said repairs along the way, and I feel posts without pics just plain suck! So I apologize to those following along for the lack of content. (it's not for lack of trying and I'm hoping 2014 I get better at this!)

Last night I had the pleasure of heading down to Scarberia to work on Brewmanagers LOTR. Exactly one month prior during his wife's birthday party / Christmas gathering the right flipper apparently got stuck and stopped working. Walt later confirmed the coil had for some reason locked on and destroyed itself, so he ordered up a replacement coil along with a couple of other new flipper parts. After successfully installing said parts the flipper failed to energize at all. Checking to make sure it wasn't something simple like a broken wire, at that point Walt knew it was time to send out the bat signal. With Christmas looming and all of the other repairs I've had on my plate as of late, scheduling this repair was proving tricky but I had a cancellation last night as did Walt so we jumped at the opportunity to resurrect the LOTR.

On arrival first thing was to pull the driver board. The main flippers on this game are controlled by Q15 and Q16, the latter being the one in question for this repair. Now, for those that don't already know... Stern Whitestar flippers are notorious for failing FET's. If you hold / cradle the ball for any length of time with any Whitestar (and maybe even SAM) games there is a very good chance the FET that controls that flipper will fail. It's a known issue and I have no idea why Stern never corrected it because they are well aware of it. Basically the FET they used for the flippers are underspec'd and destroy themselves when activated for too long. The OEM part# they have been using for high powered coils is 22NE10L. Not only is this part pretty much impossible to find these days, it's clearly not rated high enough for flipper coils. The suggested replacement is 40NE10L or an IRL540N. I prefer the IRL540N personally as it's easier to get and works great.

Quick PSA alert!!!

Please note, if shopping for an IRL540N, make sure you purchase the IRL540N and NOT the IRF540N. THESE ARE NOT THE SAME PARTS AND SHOULD NEVER EVER BE USED AS A REPLACEMENT FOR THIS APPLICATION!!! In laymen terms, the IRL version can be turned on and off with very low "logic level" voltages, which is what is required for this design. The IRF version requires slightly higher voltages to be able to turn it on and off reliably, and if used in this application what can happen is the FET will turn itself on and never turn off, ultimately locking the coil on and destroying it. (and potentially causing other PCB damage due to heat)

With the driver board out and a quick inspection I notice a couple of things right off the bat.
LOTR2.jpg

LOTR1.jpg

Not only has Q16 already been replaced by a previous owner (and unfortunately very poorly I might add as they managed to ruin ALL of the traces in the process), you can see they replaced the OEM part with the dreaded IRF540N!!! :picard:

That quickly answered Walt's question as to why this happened in the first place. I also noticed that a couple other FET's had been replaced as well (luckily all of the traces on these were still intact) and I'm guessing they were done by the same person as they too were also IRF540N! So I explained to Walt the best plan of action would be to replace the bad flipper FET at Q16 along with these other two IRF540N parts with the replacement STP40NE10L FET's that he had picked up from Starburst. The other flipper FET at Q15 was still the OEM 22NE10L and even though it was still working I also opted to pull it and replace it with the more robust STP40NE10L while I had the board out. (and ultimately save me another service call in the future)

Here are the two other IRF540N and the good OEM 22NE10L pulls, along with a quick after shot of the repair area.
LOTR4.jpg LOTR3.jpg


With the PCB work all done I quickly went over the replacement coil that Walt had installed, and for good reason. First thing to check was wires installed on coil correctly. Even though the wires were installed to the same lug locations as the original coil that was removed, they were in fact backwards! Turns out the diode on the replacement coil was installed in the opposite direction to the original, which is not uncommon and why it's important to make note of where the wires are installed on the original coils in relation to the DIODE BAND and not the coil lugs.

The next thing to check after replacing a FET or transistor is the associated diode. This can be found on the coil itself or on the driver board if not on the coil. (every FET / transistor *MUST* have one so make sure you locate it) On a new coil there is no need to verify the diode is good, but where Walt had installed the new coil and powered the game on it needed to be checked. To do this one leg of the diode must be pulled from the coil as you cannot test a diode properly when connected to a coil. With your DMM in diode "buzz" test, you should see a .4 to .6 reading on your meter with the black lead on the banded side and red on the other side of the diode. Swap the leads around and you should get nothing. Sure enough the diode on this coil was completely shorted, so a quick diode replacement, re-attach the wires to their correct lugs, replace the 3A SB fuse under the PF and it was time to test.

Power up the machine, start a game.... and LOTR lives again! Needless to say, Walt was a very happy camper and glad I was able to help him out.

D
 
Last edited:

DRANO

Super Member
Nov 15, 2012
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Mississauga
Glad you finally have it working again! A month huh? time flies.

I'd like to add to Doug's post that the transistors mentioned are also used in most Rottendog boards. I found this out the hard way.
Anyway, I have a few RD boards kicking around, so I placed an order for a bunch of IRL540 a while back. Now if only I could find them :FP:
 

Menace

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Nov 14, 2012
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Santiago de Aurora
I would say Starburst is going to be your only option if you don't want to order on-line from the USA. (or try to hit up another collector or pinball shop out in your neck of the woods?)

D
 

mwong168

Administrator
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Nov 14, 2012
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ritewhereiwant2b said:
So, does anybody know where to pick up a IRL540N in or around the Oakville/Burlington area?

Depending if you need any other pinball related parts you could place an order from Pinball Life.

Pinball Life
http://www.pinballlife.com/index.php?p=product&id=190

Great Plains and Digikey are other good alternatives and cheaper to get it from. You can also stock up on molex connectors, trifurcon pins and pin headers.

Great Plains (scroll down to 13th item)
https://www.greatplainselectronics.com/ ... sp?cat=106

Digikey
http://www.digikey.com/product-detail/e ... -ND/812000
 

ritewhereiwant2b

Well-Known Member
Dec 22, 2013
750
372
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Oakville
mwong168 said:
ritewhereiwant2b said:
So, does anybody know where to pick up a IRL540N in or around the Oakville/Burlington area?

Depending if you need any other pinball related parts you could place an order from Pinball Life.

Pinball Life
http://www.pinballlife.com/index.php?p=product&id=190

Great Plains and Digikey are other good alternatives and cheaper to get it from. You can also stock up on molex connectors, trifurcon pins and pin headers.

Great Plains (scroll down to 13th item)
https://www.greatplainselectronics.com/ ... sp?cat=106

Digikey
http://www.digikey.com/product-detail/e ... -ND/812000

Hmmmm they are cheaper! Thanks guys!
 

ritewhereiwant2b

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Dec 22, 2013
750
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Oakville
I had a tech replace the Q15 transistor on my board yesterday, I had asked him to replace Q16, but didnt have two transistors and then last night Q16 blows as Im holding the ball.

I want to try to replace it myself. I need to get thinner soldier, he had 22 gauge. He also sprayed the board and brushed it down with a tooth brush after the soldier job. Was this an anti static spray? Any recommendations on a specific spray to get?
 

mwong168

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Nov 14, 2012
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ritewhereiwant2b said:
I had a tech replace the Q15 transistor on my board yesterday, I had asked him to replace Q16, but didnt have two transistors and then last night Q16 blows as Im holding the ball.

That sucks and happens even on the new Sterns and I blew Brock's transistor on his XMLE while cradling a ball too. I hope you replaced it with better rated transistor and not the stock stern part because it will blow again otherwise.

ritewhereiwant2b said:
I want to try to replace it myself. I need to get thinner soldier, he had 22 gauge. He also sprayed the board and brushed it down with a tooth brush after the soldier job. Was this an anti static spray? Any recommendations on a specific spray to get?

If you haven't had much experience doing board work or soldering I would probably call the technician back to replace it for you. Sometimes you can cause more damage by heating things up too much or not enough resulting in ripping traces out as you pull parts out of the holes. Again not a big deal to repair but it creates more work and time to troubleshoot for a repair tech. If you have some old non working electronics like a VCR that might be good to practice soldering or else Sayal has these test boards you can practice soldering on too.

51k3QeGytBL._SY355_.jpg


In regards to the spray it was probably to clean any flux and I don't think I have ever seen Doug use this on any board repairs he has done for me. Then again he does have the midas touch and does very clean work :cool:
 

Menace

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Nov 14, 2012
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I do have the spray and depending on the type of solder used the spray works great. I usually use solder with a no-clean flux core, but I also have spools of regular rosin (which I use on wire and coils) as well as water-wash.

D
 

mitch_a

Active Member
Mar 2, 2014
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Bamberg Ontario
I normally use acetone on a qtip to clean my boards after I solder new part in to clean off any excess flux. Don't want voltage creeping across excess flux causing more problems.
 

ritewhereiwant2b

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Dec 22, 2013
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Oakville
Thanks you guys, your input is really appreciated. Ok, Mwong, I have no experience with soldering a board, but after Q15 and now Q16 blowing (Im assuming), Im like, damn, I guess I have to learn this!!!! So, I will buy that board from Sayal, Ive been on their site, looking for materials and practice. BTW, it was Doug, great guy, who helped me out - how did you know??

Anyway, I ordered some IRL540's from Marco. Ill call Doug. Such a drag, I got LOTR LE last Sunday and Im (and the Kids) sooooo psyched to play after I restored the Barad-dûr tower, cleaned the playfield, balanced the walk of the dead level, modded a target protector, put on new Super-Band sleeves and ordered the Palantir Mod!!! Ok, maybe I love my pins too much...
 

ritewhereiwant2b

Well-Known Member
Dec 22, 2013
750
372
63
Oakville
brad808 said:
ritewhereiwant2b said:
balanced the walk of the dead level,

Does the path of the dead have a level? I just got my lotr recently but I've never noticed.

It does not, but when I got mine, most all the balls went to the number 2 lane because the path of the dead area leaned to the right on my pin - as the area is not supported. So, I supported it, slightly lifted it and now it is leveled. If you have the same problem, we can discuss...