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Repaired my Samsung LCD monitor.

Started by Jan Panteltje November 6, 2011
After replacing those electrolytes in the switchmode power supply
the picture is also much sharper.
I suspect the PLL in the electronics to be more stable due to less ripple.
But more amazingly, that what I thought was burn-in of the LCD,
vertical stripes strongest at the left side, something I could never get rid of
with an anti burn in program, is almost gone.
Could have been modulation of the CFL due to a ever stronger ripple.
Dunno why it should be in sync with H the scan.
Monitor is really as new.

Jan Panteltje wrote:
> After replacing those electrolytes in the switchmode power supply > the picture is also much sharper. > I suspect the PLL in the electronics to be more stable due to less ripple. > But more amazingly, that what I thought was burn-in of the LCD, > vertical stripes strongest at the left side, something I could never get rid of > with an anti burn in program, is almost gone. > Could have been modulation of the CFL due to a ever stronger ripple. > Dunno why it should be in sync with H the scan. > Monitor is really as new. >
Maybe the H signal is used as part of the inverters switching frequency ? That would be used to turn off the lamps/inveter if no signal is at the back. Jamie
On a sunny day (Sun, 06 Nov 2011 07:37:19 -0500) it happened Jamie
<jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in
<Kiutq.23581$Gr6.4485@newsfe09.iad>:

>Jan Panteltje wrote: >> After replacing those electrolytes in the switchmode power supply >> the picture is also much sharper. >> I suspect the PLL in the electronics to be more stable due to less ripple. >> But more amazingly, that what I thought was burn-in of the LCD, >> vertical stripes strongest at the left side, something I could never get rid of >> with an anti burn in program, is almost gone. >> Could have been modulation of the CFL due to a ever stronger ripple. >> Dunno why it should be in sync with H the scan. >> Monitor is really as new. >> > Maybe the H signal is used as part of the inverters switching >frequency ? That would be used to turn off the lamps/inveter if no >signal is at the back. > > Jamie >
I dunno, the H can be very different in frequency for all the VGA standards. Also when no signal it displays this thing 'no cable' or something like that. But I am glad the thing works so well now.
On Nov 6, 5:12=A0am, Jan Panteltje <pNaonStpealm...@yahoo.com> wrote:
> After replacing those electrolytes in the switchmode power supply > the picture is also much sharper. > I suspect the PLL in the electronics to be more stable due to less ripple=
.
> But more amazingly, that what I thought was burn-in of the LCD, > vertical stripes strongest at the left side, something I could never get =
rid of
> with an anti burn in program, is almost gone. > Could have been modulation of the CFL due to a ever stronger ripple. > Dunno why it should be in sync with H the scan. > Monitor is really as new.
Power glitches or bad filter can cause those vertical lines. I don't repair LCD to see those lines, but I once saw such things during prototype design. One explanation, some circuits (PLL, counters, etc) were in "high active" at that time - which use H as the reference...