Testing a MCR106-1 Lamp Driver SCR

[Jeff (JAW)]

I have a question about testing MCR106. I have followed the directions
below as suggest on Clay's site. My question is...

I have tested all 12 SCR's on a 2518-43 Aux. Lamp Driver board. 6 test
correct with .4 to .6 one way and 1.4 to 1.6 the other. The other 6
test test OK .4 to .6 but my reading for 1.4 to 1.6 reads 0.

I have installed a new MRC106 and I still get a reading of "0" that
should be 1.4 to 1.6.

Is there a difference between MCR106 and MCR106-1? Also what else might
I check?

Thanks,

Jeff

_________________________________________________________________________________

Taken form http://marvin3m.com/bally/index3.htm#lamp

MCR106-1 Lamp Driver SCR test:

Put the black lead of your meter on the outside "cathode" leg (labeled
"C") of the SCR.
Put the red lead of your meter on the outside "gate" leg (labeled "G")
of the SCR. Your meter should read .4 to .6 volts.
Swap the meter leads. Now the meter should read 1.4 to 1.6 volts.
If your meter reads anything outside the values above, replace that
MCR106-1.

[s***@excite.com]

Post by Jeff (JAW)
I have a question about testing MCR106. I have followed the directions
below as suggest on Clay's site. My question is...
I have tested all 12 SCR's on a 2518-43 Aux. Lamp Driver board. 6 test
correct with .4 to .6 one way and 1.4 to 1.6 the other. The other 6
test test OK .4 to .6 but my reading for 1.4 to 1.6 reads 0.
I have installed a new MRC106 and I still get a reading of "0" that
should be 1.4 to 1.6.
Is there a difference between MCR106 and MCR106-1? Also what else might
I check?

Did you check the new ones before you put them in (i.e. out of
circuit?). A lot of the circuits on the boards will cause erroneous
readings like you're seeing..... check the ones you pulled out to see
how they read. As Clay says too, it's not 100% accurate, but similar
circuits should give similar results.

[GPE]

Post by s***@excite.com

Post by Jeff (JAW)
I have a question about testing MCR106. I have followed the directions
below as suggest on Clay's site. My question is...
I have tested all 12 SCR's on a 2518-43 Aux. Lamp Driver board. 6 test
correct with .4 to .6 one way and 1.4 to 1.6 the other. The other 6
test test OK .4 to .6 but my reading for 1.4 to 1.6 reads 0.
I have installed a new MRC106 and I still get a reading of "0" that
should be 1.4 to 1.6.
Is there a difference between MCR106 and MCR106-1? Also what else might
I check?

Did you check the new ones before you put them in (i.e. out of
circuit?). A lot of the circuits on the boards will cause erroneous
readings like you're seeing..... check the ones you pulled out to see
how they read. As Clay says too, it's not 100% accurate, but similar
circuits should give similar results.

Just to add to this.
MCR106 covers a series of SCR's. The base number of MCR106 doesn't specify
the maximimum working voltage -- you need a suffix to do this. The suffix
specifies the maximum working voltage and is where things vary from
manufacturer to manufacturer. Some manufacturers use letters (A, B, C,
D...) and some use numbers (1, 2, 3, 4,...). With no suffix, assume lowest
working voltage of 50V. To specify the entire number for a 50V part -- it
would be MCR106A or MCR106-1 (and lots of other variants). You can use any
SCR in this series of parts to replace these SCR's -- MCR106-1, MCR106-2,
MCR106-3, and up.

I normally carry MCR106-6's which have a maximum working voltage of 400
volts. Overkill but it's now the smallest size made by On Semiconductor
(formerly Motorola).

-- Ed

[Steve Kulpa]

Jeff,
I have a real nice test setup at home for these boards, if you'd like
to send it to me I'll check it out for you. Any repairs needed are
reasonable too.

http://www.geocities.com/stevekulpa/pinrepair.htm

steve
---
Steve Kulpa (cargpb10)
Hermitage, TN
http://www.geocities.com/stevekulpa/rgpidx.htm - Faces
http://www.geocities.com/stevekulpa/pinball.htm - Pinball

Post by Jeff (JAW)
I have a question about testing MCR106. I have followed the directions
below as suggest on Clay's site. My question is...

[Action Pinball]

SCRs are tough to check and hard to say if you're getting readings that
really indicate a good/working unit or false readings where the SCR might
fail under load (once installed).

If the lamp works when you briefly ground the return line going all the way
back, and onto, the lamp driver board, but not when you let the SCR take
control, then swap out the SCR- not uncommon for these to fail in these
games.

If still no dice, then you've got problems further upstream with one of the
decoders or something. I've replaced a LOT of SCRs over the years but as
yet, never a decoder chip.

We have the small (2N5060) and large (MCR-106) SCRs in stock for Bally and
Stern games- see: www.actionpinball.com Both are superceded by later
versions- 2N5061 and MCR-106-1- but do the same job.

Ray J.
--
Action Pinball & Amusement, LLC
Salt Lake City, Utah USA
Web: www.actionpinball.com

We're serious about pinball. Anything else is just for fun!

Post by Jeff (JAW)
I have a question about testing MCR106. I have followed the directions
below as suggest on Clay's site. My question is...
I have tested all 12 SCR's on a 2518-43 Aux. Lamp Driver board. 6 test
correct with .4 to .6 one way and 1.4 to 1.6 the other. The other 6
test test OK .4 to .6 but my reading for 1.4 to 1.6 reads 0.
I have installed a new MRC106 and I still get a reading of "0" that
should be 1.4 to 1.6.
Is there a difference between MCR106 and MCR106-1? Also what else might
I check?
Thanks,
Jeff

____________________________________________________________________________
_____

Post by Jeff (JAW)
Taken form http://marvin3m.com/bally/index3.htm#lamp
Put the black lead of your meter on the outside "cathode" leg (labeled
"C") of the SCR.
Put the red lead of your meter on the outside "gate" leg (labeled "G")
of the SCR. Your meter should read .4 to .6 volts.
Swap the meter leads. Now the meter should read 1.4 to 1.6 volts.
If your meter reads anything outside the values above, replace that
MCR106-1.