Tech: Cap Question - Which leg is +?

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Scott

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Archived from groups: rec.games.pinball (More info?)

Installing Caps into my GTB Sys1 Power Supply (not fun!).

I have an Orange Sprague Cap with a Black bar (white 0 on the black
bar) going to the short lead. Is this the + or the - lead?

I have a Black Mallory Cap with a Grey bar (black > sign on the grey
bar) going to the short lead. Is this the + or the - lead?

Thanks
 
Archived from groups: rec.games.pinball (More info?)

The short lead on both caps you have are the "-" side (negative) of the cap.
You rarely see any caps that have them "+" (positive) side marked, but I
have seen the odd few cross my desk in the past.

Doug

<scott@farrar.com> wrote in message
news:1125367401.618429.216420@g14g2000cwa.googlegroups.com...
> Installing Caps into my GTB Sys1 Power Supply (not fun!).
>
> I have an Orange Sprague Cap with a Black bar (white 0 on the black
> bar) going to the short lead. Is this the + or the - lead?
>
> I have a Black Mallory Cap with a Grey bar (black > sign on the grey
> bar) going to the short lead. Is this the + or the - lead?
>
> Thanks
>
 
Archived from groups: rec.games.pinball (More info?)

scott@farrar.com wrote:
: Installing Caps into my GTB Sys1 Power Supply (not fun!).
:
: I have an Orange Sprague Cap with a Black bar (white 0 on the black
: bar) going to the short lead. Is this the + or the - lead?

That's a tantalum cap... black bar = long lead = +


: I have a Black Mallory Cap with a Grey bar (black > sign on the grey
: bar) going to the short lead. Is this the + or the - lead?

That's electrolytic... black bar = short lead = -

Pretty dumb, eh?

--
Mark Spaeth mspaeth@mtl.mit.edu
50 Vassar St., #38.265 mspaeth@mit.edu
Cambridge, MA 02139
(617) 452-2354 http://rgvac.978.org/~mspaeth
 
Archived from groups: rec.games.pinball (More info?)

Hmmm, I don't recall there being a tantalum capacitor on the System-1
power supply. Scott, did you get your kit from Big Daddy?

Usually, radial caps (both leads out one end) have a stripe lined up w/
the negative lead. There will be at least one minus sign in the
stripe, if you look close enough. Maybe that's the "white 0" you're
seeing - it's actually a fat minus sign. ???

Axials (one lead on each end) sometimes have a plus or a minus on one
of the ends, somewhere. also, sometimes they list the tolerance w/ a
plus/minus so don't get that confused w/ the polarity plus or minus.

steve (cargpb10 - sigh)
 
Archived from groups: rec.games.pinball (More info?)

Just because it's an orange cap doesn't signify it's a tantalum.
Sprague made tons of orange electrolytics over the years.
 
Archived from groups: rec.games.pinball (More info?)

Steve Kulpa <stevekulpa@yahoo.com> wrote:
: Hmmm, I don't recall there being a tantalum capacitor on the System-1
: power supply. Scott, did you get your kit from Big Daddy?

Well, ceramics aren't polarized... dipped tantalip caps are normally
orange or yellow, but if it's sylindrical, like a normal electrolytic,
it's probably electrolytic, so the line would be minus.

: Usually, radial caps (both leads out one end) have a stripe lined up w/
: the negative lead. There will be at least one minus sign in the
: stripe, if you look close enough. Maybe that's the "white 0" you're
: seeing - it's actually a fat minus sign. ???
:
: Axials (one lead on each end) sometimes have a plus or a minus on one
: of the ends, somewhere. also, sometimes they list the tolerance w/ a
: plus/minus so don't get that confused w/ the polarity plus or minus.
:
: steve (cargpb10 - sigh)
:

--
Mark Spaeth mspaeth@mtl.mit.edu
50 Vassar St., #38.265 mspaeth@mit.edu
Cambridge, MA 02139
(617) 452-2354 http://rgvac.978.org/~mspaeth
 
Archived from groups: rec.games.pinball (More info?)

Since there are some questions about these caps, I went ahead and took
a picture of them and placed them on my webstie at the link below (its
at the bottom of the page so just scroll to the bottom):

http://www.scott.farrar.com/for_sale.htm

Any chance you guys could take another peak at the picture of these
caps to confirm which lead is Positive & which lead is Negative on
these 2 styles/brands of caps?

Thanks
 
Archived from groups: rec.games.pinball (More info?)

>From the pics, both are electrolytic and both have the negative leads
marked by their stripe. Also confirming, the short leg is negative,
the long leg is positive on that style.

The description sounded like something else and Mark was right, but the
picture tells the rest of the story.

Mike Doyle
 
Archived from groups: rec.games.pinball (More info?)

To all those that replied (again) to my second post - thanks.

Now, I'm installing these caps and I'm getting even more confused.
Unfortunately I didn't take a picture of the PCB and I don't have
another GTB Sys1 Power Supply to look at to answer my questions,
ssssoooo once again I'm depending on the power of RGP.

I'm installing these caps and some of the long positive (+) leads are
going to COM and some of the short negative (-) leads are going to COM.


This doesn't seem right to me. Can someone look at their GTB Sys1
Power Supply and verify that I have the orientation of these caps
installed properly.

I took a picture of the caps I installed - it canbe found at the bottom
of this page:
http://www.scott.farrar.com/for_sale.htm

Thanks
 
Archived from groups: rec.games.pinball (More info?)

Steve... I don't see your HH listed in the HH serial number database
;-) ...or has that PS been re-applied to another game?

df
 
Archived from groups: rec.games.pinball (More info?)

The board is marked. You see close to one end of each capacitor a +
sign signifying the + lead of the cap. It looks like you have them in
correctly. One way to tell for sure is to power the board and read your
DC voltage across any suspect capacitor and be sure the + lead has
positive voltage compared to the - lead. If reversed the capacitor will
heat and fail within a few minutes to a few days. Those capacitors are
not really great quality capacitors you are putting in, so be sure they
are right polarity real quickly or you may have an exploding one.
 
Archived from groups: rec.games.pinball (More info?)

Ahh, so I guess we can assume HH S/N 5536 has been parted out. Good to
know its organs were donated to a good cause... i.e. a BH.

df
 
Archived from groups: rec.games.pinball (More info?)

I'm not following you - are you saying you think the -80 power supply
came from a haunted house?
You can tell that from the s/n??? I don't know the entire history of
the board but I can assure you
I pulled it from a BH.

---
Steve Kulpa (cargpb10 - sigh)
Hermitage, TN
http://www.geocities.com/stevekulpa/rgpidx.htm
 
Archived from groups: rec.games.pinball (More info?)

I don't doubt it was/is in your BH... but it was origianally in a HH.
In the picture (http://www.geocities.com/stevekulpa/temp/gott80-ps.jpg)
the sticker has the number "669" in the upper-left corner, which means
that it was from Gottlieb game #669, which was Haunted House (Black
Hole was #668). Specifically, it came from HH #5536... the 537th
production machine (they started at 5000 on HH, aside from the "sample"
games)

A list of Gottlieb System 80 game numbers is here:
http://www.geocities.com/system80pins/sys80-list.html
Info about S/Ns for them is here:
http://www.geocities.com/system80pins/sys80-serial.html

df
 
Archived from groups: rec.games.pinball (More info?)

I'm going to finish installing C1 & C6 Caps tonight - plug it in - get
my voltmeter out and verify that its all working.

First, I gotta stop by church on my way home from work and say a few
prayers ;-)
 
Archived from groups: rec.games.pinball (More info?)

Prey for sure.... had a cap blow up in my face a few weeks ago while
testing a sys-1 ps i am rebuilding....
wear saftey glasses all the time!
(the cap blew bcuz there was a shorted diode before it)
your website with the pictures has exceeded bandwidth btw
 
Archived from groups: rec.games.pinball (More info?)

Yes, pray indeed. Even w/ a Big Daddy kit, repairing these is a bear
thanks to the 3 devices mounted on the heat sink, not to mention all
the stuff packed in there to boot. I actually could not get mine to
cooperate even after rebuilding it, so I ended up w/ a Rottendog
replacement.

Also, when you remove the two TO-220 devices, be sure not to loose the
little pieces of leather-like material they used to keep the TO-220
legs from shorting on the traces they go over before they're soldered
in. Also, if you can, get the thermal insulating pads instead of the
mica ones, then you don't have to deal w/ the grease - AND DON'T LOOSE
THE LITTLE NYLON WASHER-THINGIES WHEN YOU REMOVE THE DEVICES OFF THE
HEAT SINK!!! (yes I know I'm yelling)

Like I said, a real bear.

steve
 
Archived from groups: rec.games.pinball (More info?)

scott@farrar.com wrote:
> I'm going to finish installing C1 & C6 Caps tonight - plug it in - get
> my voltmeter out and verify that its all working.
>
> First, I gotta stop by church on my way home from work and say a few
> prayers ;-)

Just a follow up on this topic...long legs were POSITIVE. I got
everything installed and put back together. All of the outputs on the
board checks out so I'm happy - thanks Big Daddy (and RGP).

I've made all of the Ground mods per Clay's Sys1 on-line guide (Power
Supply, Driver Board, NiWump MPU).

Now I gotta resolve issues with my MPU (NiWumpf) as the game will reset
after playing one game AND "sometimes" locks on the Q17 Coil (driving
the Kings Drop Target Bank on Joker Poker). I'm pretty sure I've
narrowed it down to the MPU, at least that'w what the LED Diagnostics
is telling me. I guess I'll be sending it off to David to get him to
fix it as it appears to be a PAL and/or the CPU and/or ???

One day I'll get to play my Joker Poker...

Later
 
Archived from groups: rec.games.pinball (More info?)

My Ni has a bad hex inverter that was sending a constant signal to the
driver board (can't remember if it was constant high or low), which
made the driver think it was being told to energize a coil, which in
turn locked on the outhole coil, followed closely by a blown fuse. I
asked Ace for his permission to do the repairs myself so I would not
void the warranty and he said go ahead.

If you have a locked on coil, and you're sure it's the Ni's fault (i.e.
does not lock on w/ the MPU/Driver connector removed), that may be your
problem too.

Just to rub it in, I think the first thing I'll do when I get home
tonight is play a game on my Joker Poker!
Shoot - I'll play 3!!!! Na-na-na-na-naaaa-naaaa.

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