(Topic ID: 58906)

STTNG transistor upgrade

By adalogue

8 years ago


Topic Heartbeat

Topic Stats

  • 12 posts
  • 7 Pinsiders participating
  • Latest reply 8 years ago by dsuperbee
  • Topic is favorited by 7 Pinsiders

You

Linked Games

Topic Gallery

View topic image gallery

sttng_tieback_problem.jpg

#1 8 years ago

The Drop Target down xsistor seems to fail often, anyone ever try and Nte2343 as an upgrade? 120V 12A spec.

#2 8 years ago

Replacing a TIP102? Yea, the NTE2343 works fine.

#3 8 years ago

Not a fan of NTE parts. I think a TIP102 is your best option.

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com

#4 8 years ago

Yes, Tip102.

What issues have you has with NTE?

#5 8 years ago
Quoted from adalogue:

The Drop Target down xsistor seems to fail often

STTNG has 4 coils which are controlled from the auxiliary driver board. This board has an extra wire to the 50V, for a tieback diode. If this breaks or has a bad contact or so it tends to destroy transistors.

The droptarget coils and diverter coils are the ones that are controlled from this board.
I have seen many STTNGs that have burnt coils and destroyed transistors.

The droptarget down is a very small coil, and the original transistor should be ok.

What I always do (as a preventive solution) is solder diodes on those 4 coils. That way it doesn't matter if the tieback diode has a bad connection. Diodes are very cheap and it's an easy job to do.

#6 8 years ago

If you have time, read this

https://groups.google.com/forum/#!topic/rec.games.pinball/wusSfhZ9IQg

and you will solve the problem.

- Ingo

#7 8 years ago
Quoted from Richard_BoK:

...
What I always do (as a preventive solution) is solder diodes on those 4 coils. That way it doesn't matter if the tieback diode has a bad connection. Diodes are very cheap and it's an easy job to do.

Salut,

Could you please precise this a little bit more (or even better illustrate with images)?

Thanks in advance,
Regards,
flugs

#8 8 years ago

I just solder a diode on the lugs of those 4 coils. The banded side is connected to the 50V supply (violet-green wire).
Exactly the same way coils are equipped with diodes on a non-WPC game.

sttng_tieback_problem.jpg

#9 8 years ago

Thanks a lot for this explanation.

#10 8 years ago
Quoted from Richard_BoK:

STTNG has 4 coils which are controlled from the auxiliary driver board. This board has an extra wire to the 50V, for a tieback diode. If this breaks or has a bad contact or so it tends to destroy transistors.
The droptarget coils and diverter coils are the ones that are controlled from this board.
I have seen many STTNGs that have burnt coils and destroyed transistors.
The droptarget down is a very small coil, and the original transistor should be ok.
What I always do (as a preventive solution) is solder diodes on those 4 coils. That way it doesn't matter if the tieback diode has a bad connection. Diodes are very cheap and it's an easy job to do.

Sounds like an excellent solution, to an obvious and potentially very damaging design flaw.

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com

#11 8 years ago

Yes, very good suggestion.

In my case, there was a diode on the DT Down coil, which shorted and took the transistor with it.

#12 8 years ago

VERY common issue. Been helping a buddy with his STTNG, but never thought of the diode solution. I need to get over there and implement this!

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