K5synth

 > wrote:

>
> I decided to do something about the dead backlight in my K5, but  
> wanted to make sure the inverter wasn't dead also.  I never heard  
> any high pitched whine from the inverter, but decided to see if  
> there was any AC curent flowing.  I unplugged the green and violet  
> leads from the board and when I turned it on, I immediately heard  
> the very high pitched whistle coming fro the inverter.  When I  
> touched the probes from my multimeter to the pins, I got a reading  
> in excess of 100 volts (hard to read the scale accurately due to  
> fluctuation caused by my shakiness touching the pins).  From this, I  
> can presume that the inverter is still fuctioning?  When I plug the  
> dead backlight back in, the whistle isn't there.

----- Original Message -----

From: Daniel Forró

To: k5synth@yahoogroups.com

Sent: Saturday, February 08, 2014 4:31 AM

Subject: Re: [k5synth] Quick diagnostic question

Yes, it looks inverter is OK. So maybe just connection between EL foil
in display or EL foil is bad. Measure tis high voltage directly on
display contacts.

If there's a voltage, then you have to change EL foil for the new one.
Ask here:

http://www.backlight4you.com/

I have very good experience with their products and service.

It seems that display is of standard type and could be replaced by
modern one with LED backlight if there's enough space inside the
machine. It needs some modification of circuit, soldering the
connector, and removing inverter.

Daniel Forro

On 8 Feb, 2014, at 12:38 PM, > wrote:

>
> I decided to do something about the dead backlight in my K5, but
> wanted to make sure the inverter wasn't dead also. I never heard
> any high pitched whine from the inverter, but decided to see if
> there was any AC curent flowing. I unplugged the green and violet
> leads from the board and when I turned it on, I immediately heard
> the very high pitched whistle coming fro the inverter. When I
> touched the probes from my multimeter to the pins, I got a reading
> in excess of 100 volts (hard to read the scale accurately due to
> fluctuation caused by my shakiness touching the pins). From this, I
> can presume that the inverter is still fuctioning? When I plug the
> dead backlight back in, the whistle isn't there.

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4259 / Virus Database: 3697/7075 - Release Date: 02/08/14

 > wrote:
> My "new" display arrived today, and even before I installed it, I  
> plugged it into the inverter to see if the backlight worked.  It  
> did!  So I swapped the old one out for the one I just received,  
> about a 15 minute process.  Bottom line is I have a working display  
> in my K5 that I bought back in 2011 with a non-lighted display, and  
> I was getting increasing frustrated trying to see it in my setup.   
> Repaired without much fuss and for a reasonable cost.  I might still  
> try to put another backlight in the old display, for a spare or to  
> sell.  I put up a photo of the final result.