(Topic ID: 124143)

Testing Stern SAM transistors


By Syco54645

5 years ago



Topic Stats

  • 14 posts
  • 5 Pinsiders participating
  • Latest reply 5 years ago by Syco54645
  • Topic is favorited by 3 Pinsiders

You

Linked Games

Topic Gallery

There have been 2 images uploaded to this topic. (View topic image gallery).

smcapture.JPG
multimeter.jpg

#1 5 years ago

Hello,

I have a coil that is locked on in my Spiderman. How do I go about testing the transistor? I believe it is Q14 that is bad (based on the manual) but would like to test it and learn how to diagnose problems correctly rather than just replace parts on a hunch. I have looked around for how to test them but maybe I am using the wrong terminology.

Thanks

-Syco54645

#2 5 years ago

Turn the power off on the pin. Use an ohm meter and measure from the top metal part of the transistor to ground. If it reads zero ohms, its bad.
I believe that is one way to check, someone please correct me if I am wrong.

#3 5 years ago
Quoted from Hudson:

Turn the power off on the pin. Use an ohm meter and measure from the top metal part of the transistor to ground. If it reads zero ohms, its bad.
I believe that is one way to check, someone please correct me if I am wrong.

Using what you said it appears that Q15 is bad because all others are ~1.9 Mega Ohm but Q15 is 9 Ohm.
The manual states that Q14 is responsible for the upper flipper but that is the coil being held on. Wouldn't be the first time a manual was wrong I guess...

#4 5 years ago

Q14 is the upper right flipper. Q15 is the left flipper.

#5 5 years ago
Quoted from DCFAN:

Q14 is the upper right flipper. Q15 is the left flipper.

Maybe my memory is failing me then... I am waiting on the transistors to come in anyway, no spares...

#6 5 years ago
Quoted from Syco54645:

Using what you said it appears that Q15 is bad because all others are ~1.9 Mega Ohm but Q15 is 9 Ohm.
The manual states that Q14 is responsible for the upper flipper but that is the coil being held on. Wouldn't be the first time a manual was wrong I guess...

Make sure you have the meter set to resistance:

multimeter.jpg

#7 5 years ago

smcapture.JPG

#8 5 years ago

Thanks for the replies. I checked the manual but t as I said my memory may be failing me. Definitely had the meter on resistance so I think it is actually Q15 that is bad. Wish I had an extra MOSFET laying around. Or that RadioShack stocked then.

#9 5 years ago

While you are waiting on your replacement transistor, desolder the bad one and put the board back in. You will find that the coil is no longer locked on.
Just something to kill time with...

#10 5 years ago
Quoted from Mrjamma:

While you are waiting on your replacement transistor, desolder the bad one and put the board back in. You will find that the coil is no longer locked on.
Just something to kill time with...

Yeah that idea crossed my mind but then my power went out. Maybe I will do it tonight. Have a lot of work to catch up on tonight and tomorrow...

#11 5 years ago

I'm kind of hesitant to mention this, but here goes. If you don't have a shaker motor installed, Q6 is unused and is of the same type as Q15. Disclaimer: I only mention doing this if you have the proper equipment that will allow you remove Q6 without damaging your I/O board. If all you have is solder wick, a hand held solder sucker, or a cheap soldering iron, forget it. Don't mess up your board removing a transistor to swap into another location. But if you want to get your game going an you have the right tools, this is a way to do it.

I know you've already ordered the transistor but I'll mention this anyway. Ed at Great Plains Electronics stocks the MOSFET (transistor) that you need: STP40NF10L. This is a more robust part than what is currently on the I/O board (40 amp vs. 20 amp). Especially for the flippers it is better to use a more robust part. Stern even started using higher current FETs for their later I/O boards (46 amp I believe).

#12 5 years ago
Quoted from stangbat:

I'm kind of hesitant to mention this, but here goes. If you don't have a shaker motor installed, Q6 is unused and is of the same type as Q15. Disclaimer: I only mention doing this if you have the proper equipment that will allow you remove Q6 without damaging your I/O board. If all you have is solder wick, a hand held solder sucker, or a cheap soldering iron, forget it. Don't mess up your board removing a transistor to swap into another location. But if you want to get your game going an you have the right tools, this is a way to do it.
I know you've already ordered the transistor but I'll mention this anyway. Ed at Great Plains Electronics stocks the MOSFET (transistor) that you need: STP40NF10L. This is a more robust part than what is currently on the I/O board (40 amp vs. 20 amp). Especially for the flippers it is better to use a more robust part. Stern even started using higher current FETs for their later I/O boards (46 amp I believe).

Well I ordered IRL530. I have a Soldapullt and a Hakko 888D. I do not have the shaker motor now but would like to get it in the future. I thought of pulling that transistor to get the game up and running at least but meh, do it right.

#13 5 years ago

If the info I'm finding is right, the IRL530 is lower amperage than what is currently in the game (14A vs. 20A. You really want to go with at least an IRL540 (26A) or the STP40NF10L.

#14 5 years ago
Quoted from stangbat:

If the info I'm finding is right, the IRL530 is lower amperage than what is currently in the game (14A vs. 20A. You really want to go with at least an IRL540 (26A) or the STP40NF10L.

You are correct. I ordered IRL540N but fat finger friday is in effect... Those should be 36A.

Promoted items from the Pinside Marketplace
$ 54.99
Cabinet - Shooter Rods
Lighted Pinball Mods
From: $ 20.00
Cabinet - Other
Rock Custom Pinball
$ 54.99
Cabinet - Shooter Rods
Lighted Pinball Mods
$ 35.00
Cabinet - Decals
Pinball Haus

Hey there! Got a moment?

Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside