Re: Power Driver Board Bridge Rectifier / Capacitor replacement


<tbanthony@xxxxxxxxx> wrote in message news:3571c08a-7de7-4fbd-bfd6-14e2d3ed395d@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Mar 13, 11:46 am, RonKZ650 <RonKZ...@xxxxxxx> wrote:
Regardless of what has been written on the subject a bad capacitor
cannot possibly hurt the bridge or reduce it's life. The "life" of a
capacitor depends on many things, a couple of which are ripple
current, and heat from surrounding parts ect. Ripple current is how
much AC is being filtered by the capacitor which translates to heat
and less life. Heat from surrounding parts causes the same thing. Heat
is what generally determines the life of an electrolytic capacitor.
Also quality of the original part has a lot to do with life. Saying a
capacitor lasts 10yrs is really not possible. It all depends on
factors. More hours the game is used the less life any part will
have.
On Mar 13, 9:31 am, tbanth...@xxxxxxxxx wrote:



> On Mar 13, 11:23 am, tonya111...@xxxxxxxxx wrote:

> > On Mar 13, 8:14 am, "John Wart, jr" <johnwar...@xxxxxxxxxxxxxx> wrote:

> > > I almost always replace the associated cap(s) when I do the bridge
> > > rectifier, then do the jumper mods.

> > > Helps keep the output of the bridge 'smooth', and with the 'newest' > > > WPC 89
> > > game being over 10 years old, the caps have deteriorated and don't > > > owe
> > > anyone anything.

> > > I'd rather pull the board only once :) But, YMMV

> > > --
> > > --john

> > > CARGPB34http://www.myhomegameroom.com

> > > <tonya111...@xxxxxxxxx> wrote in message

> > >news:7f6d3d74-261b-460c-9639-8ae81b168d0c@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> > > On Mar 13, 8:04 am, "John Wart, jr" <johnwar...@xxxxxxxxxxxxxx> > > > wrote:

> > > > I fail to see why you need to improve the life of BR4, assuming > > > > it's the
> > > > one
> > > > WMS installed on the board in the mid 90s :)

> > > > If it keeps failing, you may have problems elsewhere.

> > > > --
> > > > --john

> > > > CARGPB34http://www.myhomegameroom.com

> > > > <tbanth...@xxxxxxxxx> wrote in message

> > > >news:7c1222ef-51c2-4240-aea9-ba3ebebe7b63@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

> > > > > I'm replacing the BR4 bridge rectifiers on my STTNG. I was going > > > > > to
> > > > > replace the cacitor C111 as well for good measure while I was at > > > > > it.
> > > > > However, what can I do to improve the life of my BR4?

> > > > > Should I use a reduced value capacitor such as a 12000uF?

> > > > > The capacitor I ordered is the standard 15000uF but I think it's > > > > > rated
> > > > > 400v rather than 200v which I thought was ok and it seemed to be
> > > > > listed as the standard replacement to use, but is this going to > > > > > cause
> > > > > a problem?- Hide quoted text -

> > > > - Show quoted text -

> > > I would just replace the bridge and leave the rest alone!- Hide > > > quoted text -

> > > - Show quoted text -

> > John, Can he use the cap he mentioned? This is also his first board
> > repair. That is why I said keep it easy. On that same note. I never
> > had to replace the cap, Maybe I should start!- Hide quoted text -

> > - Show quoted text -

> The Electrolytic Capacitors: the Bridge Rectifier and Diode's Partner.
> Each bridge rectifier or diode set must also have an associated
> electrolytic capacitor. These are needed to polish the converted rough
> DC voltage to smooth DC voltage.
> Electrolytic caps are largely mechanical devices. With time, they can
> fail. Expect about 10 years maximum life from an electrolytic filter
> capacitor. It is fairly common for these caps to fail.

> ... so I was going to replace the cap while I was messing with the
> bridge rectifier. A failing capacitor can take out the BR from what
> I read somewhere. The cap is 35v not 400v. Sorry, the BR is 400v
> vs. the current 200v which I understand to be ok. Guess I was really
> focused more on the 15000uF value.- Hide quoted text -

> - Show quoted text -- Hide quoted text -

- Show quoted text -

I was quoting http://www.pinrepair.com/wpc/index2.htm in my prior
post. I'm sure the 10 years is an estimate based on average use or
was some experiential factor of seeing some failures at that age of
machine. I wasn't taking it too literally. The machines are 15
years old and my machine looks like it's seen it's fair share of use,
so I was going to replace the cap while I was replacing the BR. It
seems reasonably well documented that the BR's and Caps tend to be
what fails on the board. I don't know if that's 1% or 20% after 15
years. If the cap failure doesn't cause a chain reaction of other
problems, then I'll leave it alone. If the cap failure could take
something with it or a failing cap could have helped bring the demise
of my BR, then I'd prefer to replace it while I've got the board out
of the machine. The voltage of the capacitor seemed to be concern on
another post related to a different cap. The cap I bought from Bay
Area is 35v and is described as being for the Power Driver Board. I
believe the original C11 is 25v. I didn't think this would be a
problem but I value others expertise on all of this.

-----------------------------------------------

Having a higher voltage rating on a cap will have no detrimental effects... other than it will be physically larger and tend to cost more. If the original was 25V -- you can use 35V with no worry.

Now... the biggest issue:
Why does Outlook Express sometimes put ">"s in front of quoted text and the next time it doesn't? Under the options tab, it's set to always insert ">"s at the front of included text...but it seems to ignore that. YASMP (Yet another stupid Microsoft product)

-- Ed



.

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