Good information. My Nightlaunch backlight is
still going strong on my other gear, and I suppose I should get one for my
K5. First I will try the re-solder thing since the Kawai tech support guy
told me the same thing. Can I find the inverter easily? Is is
connected directly to the backlight?
Didobrain
----- Original Message -----From: nelsonj_sceSent: Tuesday, September 14, 2004 11:57 PMSubject: [k5synth] Re: New Backlight - inverter problemsUpdate:
Well today I ordered a new inverter from www.DigiKey.com. I found an
inverter that looks like it will do the job - for those interested it is:
Digikey part # 289-1032-ND and it only cost $11.90 - not bad.
I am not sure if it will fit exactly in the same slots as the original
inverter so it might require some additional wiring.
Anyway, I had my K5 open to look at the power supply to plan the new
inverter install when my K5 started "humming", and guess what, I now
have a beautiful blue backlight. It looks great, a very cool blue.
So it appears my inverter was not bad, but it just has bad solder
joints. It is working for now but tomorrow I will likely take out the
board and redo all the solder joints.
Just some additional info I learned in researching backlights and
inverters. The "brightness" of the backlight is a function of the
voltage and frequency applied to the backlight. It appears one has a
lot of flexibility in selecting the inverter output voltage and freq.
For example, nightlauch says you can "test" the backlight by plugging
it directly in to a wall socket (120V AC @ 60 Hz here in the US)! The
higher the voltage and freq the brighter the backlight. However, the
backlight will "burn out" quicker the higher the freq. So there is a
trade off, high freq = bright but shorter life.
Right now my stock inverter is putting out about 102V @ 380 Hz. I
think the inverter I ordered will put out about 95V @ 540 Hz and
should work with a 3 - 6 V DC input.
Next step, 147k resistors (also ordered from Digikey today).
--- In k5synth@yahoogroups.com, "nelsonj_sce" wrote:
> Well I replaced my backlight with one I ordered from
www.nightlaunch.com.
>
> It took less than two weeks from when I ordered and the parts look
good.
>
> Good news/bad news though on my backlight.
>
> The good news: I had no problems removing the LCD, taking out the old
> backlight and sliding in the new backlight. The new light has some
> wires and a plastic "tab" that kind of gets in the way, so I soldered
> the backlight wires to where the wires connect to the LCD board.
> Hint:You have to cut the new backlight to size, so make the backlight
> a little longer (say 1/4 inch) than the original to make things easier.
>
> Bad news: My backlight does not work but I think my inverter is the
> problem. I am only getting about 1/2 Volt at the output of my
> inverter, and I am supposed to get 120V @400Hz if I understand the
> part correctly. I tested my inverter before I did the backlight
> install and saw it had low voltage, but I was hoping that my existing
> "dead" backlight was causing the problem (i.e. it was shorted.) I
> guess not because even with the new backlight I get very low voltage.
>
> Anyway, it looks like I need to get an inverter. I can get an
> inverter from nightlaunch for $17.99+s/h but it needs 9V DC. I
> understand the inverter in the K5 uses 5V DC.
>
> Q1: Does the K5 inverter use 5V DC?
> Q2: If I measure the voltage on the two wires to the left of the
> inverter, should I get 120V if everything is working? (My Fluke says
> it is good <=1kHz)
> Q2: Does anyone know where to get a compatible K5 inverter and how
> much it will cost?
>
> Thanks again for all the help. This group is great.