Re: sencore cr70 repair

I finally dug into my Sencore CR70. Looks like IC4 (TL084 quad opamp) was
dead.

The problem is that after replacing IC4 it's no longer calibrated and it's
failing the test procedure. The voltage on G1/G2 is supposed to swing from
20 to 400 volts but it's actually swinging from 80 to about 460 volts.

Can anybody help explain the purpose of pots R24, R23, and how I might want
to adjust them to recalibrate the unit properly? It looks like I need to
adjust both of these but I don't know how.

-joey

On Tue, Jan 15, 2013 at 10:45 AM, Joey Oravec <joeyoravec@gmail.com> wrote:

> I got ahold of Sencore today. Unfortunately (like I expected) the CR70 is
> "obsolete and we cannot accept it for repair". The lady was pretty nice and
> she's looking around to see if there's any service information or a
> calibration procedure, but it's not too optimistic.
>
> I already have the schematics, parts list, and manual but there are
> various pots that surely need adjustment after changing out components.
> Hopefully she finds that procedure.
>
> -joey
>
>
> On Mon, Jan 14, 2013 at 3:02 PM, Louis Srianomai <louisurfer@yahoo.com>wrote:
>
>> I sent mine in to sencore itself a few years back. With return shipping
>> it was a couple hundred bucks.
>>
>> ------------------------------
>> *From:* Joey Oravec <joeyoravec@gmail.com>
>> *To:* vectorlist@vectorlist.org
>> *Sent:* Monday, January 14, 2013 11:55 AM
>> *Subject:* VECTOR: sencore cr70 repair
>>
>> Does anybody know of somewhere in the USA that can repair and calibrate
>> Sencore CR70 CRT rejuvinators? Mine has something wrong on the green cutoff
>> test. The needle spikes low and cannot be adjusted.
>>
>> I'd consider digging in and trying to fix it, but there are a bunch of
>> adjustable pots and I didn't see a calibration or self-test procedure in
>> the user manual or the repair manual. Without a self-test or calibration it
>> seems like a shotgun repair might end up doing it more harm than good.
>>
>> -joey
>>
>>
>>
>

---------------------------------------------------------------------------
** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org
** Please direct other questions, comments, or problems to chris@westnet.com
Received on Mon Feb 25 17:41:36 2013