[wxsig] Help with T-238 failure

[John Koster]

I have spare MPU and RS232 chips here.  I don't for the 32MHz oscillator 
module, since it's a different version for T238+  

On Wed, 29 Jun 2005 Sct599 at aol.com wrote:

>  
> Hi John:
>  
> Thank you for the response. 
>  
> LCD: When I initially found the unit after the failure, the display had  
> random unintelligible blocks of pixels. These pixels would change in response to  
> pushing the "Select" button. After subsequent power ups, the display is blank 
> of  any pixels. The back light remains functional. With it showing the random 
> pixels  initially indicate that it may have survived the event?
>  
> Crystals: I will check these as soon as I can and report back. Believe it  or 
> not, my scope is only a 5Mhz!
>  
> PC port: I had thought about doing this but did not since there was no  
> "heartbeat" LED activity. Heartbeat LED checked out OK. Should I give it a try  
> anyway?
>  
> Thanks again,
> Scott
>  
>  
>  
>  
>  
> In a message dated 6/29/2005 10:43:26 A.M. Mountain Daylight Time,  
> w9ddd at tapr.org writes:
> 
> Any  indication that the LCD module survived?  For some reason that and the  
> crystal modules would be the first suspects on my list.  You should  be 
> able to talk to the unit without the LCD though via the PC port.   
> 
> I'd start by verifying the oscillator works with either a scope or  logic 
> probe that's good to 32MHz.  Nothing happens with the 32MHz  clock working.
> 
> On Wed, 29 Jun 2005 Sct599 at aol.com wrote:
> 
> >  Hello Group:
> >  
> > I am looking for any input you all may be  able to provide concerning a  
> > failure with my T-238 (original  model).
> >  
> > Found that the U5 voltage regulator had failed  putting approx 11 volts on  
> > the 5 volt buss. Replaced U5 and no  indication of unit coming back to 
> life.  
> > Performed the "Power up  and initial testing" procedure and all appears to 
> be OK.  
> > Is it  safe to assume that the U3 microprocessor and possibly all 
> components   
> > powered by the 5 volt buss have been destroyed?  If so, is there  any hope  
> in 
> > repairing this unit?
> >  
> >  73,
> > Scott - NØLNE
> >  _______________________________________________
> > wxsig mailing  list
> > wxsig at lists.tapr.org
> >  https://lists.tapr.org/cgi-bin/mailman/listinfo/wxsig
> > 
> 
> --  
> 73,
> John,  W9DDD
> 
> 
> _______________________________________________
> wxsig  mailing  list
> wxsig at lists.tapr.org
> https://lists.tapr.org/cgi-bin/mailman/listinfo/wxsig
> 
> 
> 
> 
> _______________________________________________
> wxsig mailing list
> wxsig at lists.tapr.org
> https://lists.tapr.org/cgi-bin/mailman/listinfo/wxsig
> 

-- 
73,
John, W9DDD