[sdiy] Bizarre LCD Display Behavior & Is backlight AC or DC Voltage?

[ASSI]

On Mittwoch 24 September 2008, Ken Elhardt wrote:
> Does anybody know whether the backlights are powered by
> an AC or DC voltage in these types of displays?

The K5000 has an EL backlight foil that is driven by ~100VAC at some 
hundred Hertz (you can hear it whine, mine's around 400Hz which can 
be bothersome).  There is some tradeoff between frequency and voltage 
on these EL foils (they get brighter as both are increased, up to a 
point) so your's could be different if they used different 
backlicghts over time.  Since you seem to have problems with the 
inverter itself you should replace it or, especially if this display 
has already seen a few years of use, you can get a replacement kit 
for both the foil and the inverter.  There used to be a UK(?) shop 
that sold kits online ready-made for various synth models, but I 
can't find the link anymore.  Anyway, inverters and foils you can cut 
to size are available from several electronics distributors.

> And is there ever 
> a normal situation when a signal can't be probed and looked at on a
> scope and emits a continuous spark between probe and point of
> contact?

RF does that too.



Achim.
-- 
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk]>+

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