Re: OT: Vortex issue

[Toby G <carpet8@mac.com>]

Really you need a o-scope and a schematic.  You wanna look at the signal 
at 
various points.  Unless you can see with your own eyes that a component is 
burnt it's gonna be quite difficult.

t


----- Original Message ----- 
From: "d.nix" <d.nix@comcast.net>
To: <cnovey@gmail.com>
Cc: <Loopers-Delight@loopers-delight.com>
Sent: Wednesday, May 12, 2010 10:23 PM
Subject: Re: OT: Vortex issue


> Generally speaking, you cannot test most components in circuit, as the
> surrounding connections and components prevent you from getting proper 
> clean
> values of just the questionable part... Some times, depending on the 
>type 
> of
> part and the type of circuit, you can measure voltages across the various
> components and deduce if its functioning properly - but you *really* 
>need 
> to
> know what you are doing, and know what a properly fucntioning device 
> should
> measure.
>
> You also have to do this with it powered up, and if you make a mistake 
>and
> short out the wrong terminals, you can fry stuf and cause more damage. As
> well as shock yourself....
>
>
> ----- Original Message ----- 
> From: "Clifford Novey" <cnovey@gmail.com>
> To: <Loopers-Delight@loopers-delight.com>
> Sent: Wednesday, May 12, 2010 8:43 PM
> Subject: Re: OT: Vortex issue
>
>
>> U32 is actually soldered to the board which is a pain- wish it was in a
>> socket. I need a book to teach me the basics of this like how to test
>> components,etc. I have a small cheap multitester but don't know much 
>else
> as
>> far as how to use it on installed caps,diodes,etc. and what settings and
>> values should show. Tempted to run to Radio Shack before they close and
> get
>> a nicer digital one.
>> C
>>
>>   Not being able to measure on your device, I can't tell too much..
>> >> Could be the output opamp U32 (Motorola MC 34072, dual opamp) or the
>> >> output voltage swing clamping diodes D12/D13 (1N4148 small-signal
> silicium
>> >> diodes).
>> >>
>> >> Those are located fairly close to the jacks, and I believe labeled on
> the
>> >> PCB close to each component.
>> >> IIRC U32 is in a socket, so it's easy replacing it.  I don't know 
>> >> about
>> >> availability today; it's possible you may need a replacement part.
>> >>
>> >>
>> >> --
>> >> rgds,
>> >> van Sinn
>> >>
>> >>
>>
>
>