Thanks Glen.  This is just the kind of information I need.  I can figure out
where the capacitors are in the power supply and test them.  One question,
is there a way to test a capacitor without a capacitance meter?  In case the
capacitor(s) have a good charge aboard, I probably shouldn't be poking
around with a volt meter, or should I try to discharge them first(how do I
do that?).

John

----- Original Message -----
From: "McComas_Glenn" <mccomas@shore.intercom.net>
To: <jbclem@earthlink.net>
Cc: <vanagon@gerry.vanagon.com>
Sent: Saturday, May 27, 2000 4:34 AM
Subject: Blaupunkt amplifier blowing fuzes

> John --
>
> My 2� worth from several experiences with 'antique' vacuum tube
> electronics:
>
> Sounds like a capacitor in the power supply section may have gone bad.
> This can create a path to ground (earth) where one did not exist
> before, so that while the unit works briefly, the resistors in the
> power section are heating up (well above design value) and the current
> draw is large (again relative to design value).
>
> If you are lucky enough to get a schematic for the amplifier, that
> will make it easier to identify the power section, as you already
> know.  Finding suitable repair parts can be a bit of a quest also,
> since they have to fit in a given space.  Nobody is generally
> optimistic about replacing parts without knowing the 'why' but......
> you could try replacing the capacitors and rectifiers near the area
> where you detect heating.  This can mean searching the
> sites/catalogues of a number of electronics surplus houses..... akin
> to finding parts for an old VW.
>
> Hopefully someone more knowledgeable in electronics will respond to
> your post, and maybe Darrell  midwesty@midwest.net  will have
> something to say?  He fixes Vanagon ECUs and should have the
> instruments to begin a checkout procedure.  Choosing someone well
> qualified and budgeting for some diagnostic time should put you on the
> right path.....
>
> Best of luck!
> Glenn
> Queenstown, MD
>
> ================REFERENCE===============
>
> Date:    Fri, 26 May 2000 13:54:59 -0700
> From:    John Clemens <jbclem@EARTHLINK.NET>
> Subject: Blaupunkt amplifier blowing fuzes
>
> My 1983 Westphalia has been musically well serviced for years by a =
> Blaupunkt BPA-260 amplifier
> (60W per channel-2 channels).  Along with a Blaupunkt Tucson tuner I =
> have very good reception and the nice crisp Blaupunkt sound.  Last
> week =
> the fuze to the amplifier starting blowing everytime I turned the
> radio =
> on(the amp is triggered on by 12v from the tuner...the fuze is on the
> =
> other power lead to the amplifier).  I've measured a current of 32
> amps =
> going to the amplifier which is way abnormal and making it heat up and
> =
> after a few minutes blowing the fuze(15 amp fuze blows right away, 25
> =
> amp fuze takes a little longer).  Looking inside at the circuit board
> I =
> don't seen any sign of a hot spot, no blackened areas, no obvious =
> shorts.  There is a section that is heating up more than the other =
> sections.
>
> Is there someone on the list who knows enough to help me troubleshoot
> =
> this.  I'm not sure I can get a schematic because the amp is probably
> 10 =
> years old, but I can try the Blaupunkt web site.  Or is there someone
> =
> who does inexpensive repairs of this type.  I suspect there is just
> one =
> component that is bad, and since the fault is so obvious, a
> knowlegeable =
> person would find it quickly.
>
> This is always the dillema in these days of throwaway electronics.
> The =
> electronic repair shops have minimum rates that often force a person =
> into buying a replacement instead of repairing, but when you have =
> something of good quality that just happens to be old), you inevitably
> =
> end up buying something that costs twice as much and is half as good.
> =20
>
>
>