LCD noise

[roryhinds]

anyone else have a high pitch noise coming from the LCD?

[Billy Summers]

anyone else have a high pitch noise coming from the LCD?

That's the sweet sound of 4k humming right along...:sarcasm:

[Brook Willard]

Yep... I've heard it on most [if not all] RED LCDs I've handled. I'm sure there's a solution...

[Simon Blackledge]

earplugs :-/

[BASSAM MSSALATIE]

i think we need update for firmware

[Kevin Halverson]

From the description it 'sounds' like it might be the inverter for the CCFT backlight. This is a hardware behavior and wouldn't be effected by a firmware change.

[BASSAM MSSALATIE]

i think we must notify redteam for this problem trying to fix it:alien:

[roryhinds]

I hope this can be fix as its too noisy

[Brent J. Craig]

I agree it is probably the backlights. I have seen this behavior in a few Palms and some cheapo desktop LCDs.

[Wes Printz]

From the description it 'sounds' like it might be the inverter for the CCFT backlight. This is a hardware behavior and wouldn't be effected by a firmware change.

I would agree, two possible solutions, head back to the manufacturer of the Inverter PCBA for a fix, a change of a capacitor value in the oscillator may be the cure, or try waxing the HV Coil to prevent the windings in the coil from vibrating. I've done the later on a few LCD monitors in the past, But, I'm sure this would void any warranty the fine folks offer.

[Simon Valderrama]

I would agree, two possible solutions, head back to the manufacturer of the Inverter PCBA for a fix, a change of a capacitor value in the oscillator may be the cure, or try waxing the HV Coil to prevent the windings in the coil from vibrating. I've done the later on a few LCD monitors in the past, But, I'm sure this would void any warranty the fine folks offer.

i guess if you also implement a good flux capacitor you could travel in time.
works best if the LCD is used inside a Delorean DMC-12!
:nuke:

[Kevin Halverson]

I would agree, two possible solutions, head back to the manufacturer of the Inverter PCBA for a fix, a change of a capacitor value in the oscillator may be the cure, or try waxing the HV Coil to prevent the windings in the coil from vibrating. I've done the later on a few LCD monitors in the past, But, I'm sure this would void any warranty the fine folks offer.

The root cause of mechanical noise in an inverter design is two main areas. First is the excitation frequency used to drive the magnetics (and to a lesser extent the FTs themselves). Here all that is required to reduce the noise level is to choose a higher frequency. Changing a single capacitor to effect this frequency could work (depending upon the design of the oscillator). The second noise contributor is the fundamental nature of the oscillator / step-up circuit. Many, low cost approaches are self oscillating and drive the magnetics with effectively fixed period square wave excitation. This choice, while certainly the lowest cost one, is also the noisiest approach possible.

In the end, simply a better power supply design would result in reduced mechanical noise, but at a higher cost. Once service guides are released which include schematics for this aspect of the monitor, it will be a simple matter to determine if a 'quick fix' is possible.

[nzben]

I agree it is probably the backlights. I have seen this behavior in a few Palms and some cheapo desktop LCDs.

My Palm Pilot makes a high pitch whine as well. It's quite annoying. The LCD apparently has a LED back lighting system, not tubes.

EDIT: Reffering to the back lighting in the Red LCD, not the Palm

[Leif Thomas]

I got a Palm aswell and there are software sollutions for that problem. Programms like Warp Speed (http://www.palmpowerups.com/readarticle.php?article_id=7) or "Whine Hack" eliminate the annoying sound. Understanding that the sound comes from the same piece of hardware (inverters), I think they can be treated and corrected the same way (with software)?!

[Jarred Land]

dont worry we are listening...

( sorry for the pun )