Hi

The problem is that when connected laptop to lcd tv, while laptop
running on ac power, the tv screen flickers. When switched to battery,
screen looks smooth without any issues. Plug in powerd cord again and
the screen starts flickering again.

Any idea what could be a problem. Tried all resolutions, refresh rates
and nothing improves the quality. The problem only occurs while laptop
connected to ac power. Thought that maybe could it be that processor
speed interferes, but while running on battery set up all to max speed
and everything seems fine, screen looks smooth. While on ac power,
even when reduced processor speed to minimum, I could say that it
improves the quiality a little, but still visible noise on the screen.

Please help

Possibly smoothing cap in Powersupply faulty,
causing interference to go through the laptop to the tv?
Perhaps try another PSU (if u have one)
P
wrote in message
oups.com...
Hi

The problem is that when connected laptop to lcd tv, while laptop
running on ac power, the tv screen flickers. When switched to battery,
screen looks smooth without any issues. Plug in powerd cord again and
the screen starts flickering again.

Any idea what could be a problem. Tried all resolutions, refresh rates
and nothing improves the quality. The problem only occurs while laptop
connected to ac power. Thought that maybe could it be that processor
speed interferes, but while running on battery set up all to max speed
and everything seems fine, screen looks smooth. While on ac power,
even when reduced processor speed to minimum, I could say that it
improves the quiality a little, but still visible noise on the screen.

Please help

If processor speed really does affect this, then could be bad
or inadequate filtering in the powre supply as suggested below.

Long shot but make sure the laptop is plugged into the same AC circuit
and try reversing the laptop or TV plug if they aren't polarized.

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"Peter K" writes:

Possibly smoothing cap in Powersupply faulty,
causing interference to go through the laptop to the tv?
Perhaps try another PSU (if u have one)
P
wrote in message
oups.com...
Hi

The problem is that when connected laptop to lcd tv, while laptop
running on ac power, the tv screen flickers. When switched to battery,
screen looks smooth without any issues. Plug in powerd cord again and
the screen starts flickering again.

Any idea what could be a problem. Tried all resolutions, refresh rates
and nothing improves the quality. The problem only occurs while laptop
connected to ac power. Thought that maybe could it be that processor
speed interferes, but while running on battery set up all to max speed
and everything seems fine, screen looks smooth. While on ac power,
even when reduced processor speed to minimum, I could say that it
improves the quiality a little, but still visible noise on the screen.

Please help

It might be a ground loop. I had this problem several twice (using
Desktop PC and laptop) (in Germany...) and both times it was a ground
loop. A solution may be to use a _STRONG_ wire to link the grounds of
the devices to avoid the current flowing through the thin Ground lead
of the cable.
If you have one, you could try an isolation transformer before the
power supply, but du NOT connect the laptop's ground!

There is a ground loop occurring between the AC mains and the signal ground
coming from the laptop to the TV. They both use different field rates
internally.

If you can find a way to isolate either the power supply in the laptop, or
the power supply in the TV, this will fix the problem.

One thing you can try, is if the laptop has a ground pin on its AC cord,
invest in a ground lift adaptor at the hardware store, or if you safely know
how, buy the pieces and make on one up your self.

If the laptop uses no dedicated AC mains ground, and is using a polarized AC
mains connector only, then you will have to research out how to do an
isolation on it. This may mean opening the power supply and working out some
design changes, which I do not advise, unless you are skilled in designing
power supplies.

--

JANA
_____


wrote in message
oups.com...
Hi

The problem is that when connected laptop to lcd tv, while laptop
running on ac power, the tv screen flickers. When switched to battery,
screen looks smooth without any issues. Plug in powerd cord again and
the screen starts flickering again.

Any idea what could be a problem. Tried all resolutions, refresh rates
and nothing improves the quality. The problem only occurs while laptop
connected to ac power. Thought that maybe could it be that processor
speed interferes, but while running on battery set up all to max speed
and everything seems fine, screen looks smooth. While on ac power,
even when reduced processor speed to minimum, I could say that it
improves the quiality a little, but still visible noise on the screen.

Please help