Know Anything About Computer Crt Monitors?


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lately i've been trying to get a viewsonic g225fb that works. the first one flickered at anythng below 120hz expecially in the upper left hand corner, the second work find at first then started flickering in the lower left hand corner at 85hz.... so then i sent it bakc to viewsonic for repair. the day that i recieved it back it would start making a hissing/buzzing sound in the back of the monitor at 1600x1200 at 85hz, that being the optimal setting for the monitor so says the instructions. it wouldn't make the sound at ANY other setting, including those with even higher frequencies such as 1600x1200 at 100hz. after a while i noticed that if i left the monitor on at another setting for a while, then switched it to the 1600x1200 at 85hz setting the hissing wouldn't occur, but it would still happen if i left the monitor off for 5 minutes and then turned it back on at the 1600x1200hz setting. now, the sound seems to not occur at all. i got the monitor back last wednesdy i think.

i've asked for my money back as i don't trust this thing. should i send it back? no? and do any of you have any idea what's wrong with this monitor? with the previous ones?

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Short answer-

it needs a major part replaced... factory did a quick fix on it.

the hiss is an arc... turn off the lights and look down the ventilation slits... see *anything at all*?

I could be wrong... but I've seen this many times...

Could also be more minor... but will ultimately lead to the same result- arcs.

Longer Answer-

The hiss is caused by the monitor trying to synchronise at a particular frequency.

If it is worse case scenario-

the monitor may already be arcing internally. The corners reacting differently from each other led me to think this is your problem already.

If it is NOT worse case-

If it isn't 'just right', you may hear a hiss. The hiss will disappear when the hardware finally 'catches' and is in sync. This will only ever get worse as it ages.

Biggest problem-

Both scenarios share too many characteristics in the real world... And both scenarios mean the manufacturer didn't repair it properly.

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How many monitors have you 'burned through'?

Perhaps your video card is overheating and over-driving the video?? Or maybe your monitor isn't on a protected circuit?

**Brand new** monitors shouldn't hiss at all.

Could your power to the monitor be 'dirty'?

Have another video card to test your replacement monitor on before using with your normal video card? Your card could be killing the screens....?

Is your video card overclocked??? If it is... then that is most likely killing these poor monitors...

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  • 2 weeks later...

You may be using the wrong graphics driver that is trying to run your monitor on too high of a refresh rate or you have set your refresh rate too high. Lower your refresh rate.

Right click your Desktop and select Properties. Click the Settings tab then the Advanced button. Click the Monitor tab and set the Refresh rate to 70 Hertz. Make sure the box is checked to hide modes the monitor doesn't support. I would also reduce the resolution to 1024 x 768 for now.

If the hissing has gone away you are on the right track to solve the problem.

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  • 3 months later...

Usually if the monitor makes hissing and popping noises at the back it means that the connection from the LOPT (transformer) to the anode on the screen is loose, there is a way of fixing this but it wont always work. BEWARE THAT THIS IS VERY DANGEROUS. THERE ARE VOLTAGES IN EXCESS OF 30000 VOLTS AND THE TUBE CAN IMPLODE CAUSING A GREAT DEAL OF INJURY. THIS IS NOT FOR IDIOTS - YOU PERFORM THIS CHECK AT YOUR OWN RISK - I WILL NOT BE HELD RESPONSIBLE FOR ANY DEATH OR INJURY AS A RESULT OF THIS. THIS CAN KILL YOU. YOU HAVE BEEN WARNED!

Anyway, unplug your monitor and take the back off. The first thing you should see is a red cable going from the circuit board to the tube (the screen). You need 2 LONG metal screwdrivers WITH PLASTIC HANDLES. Slide 1 screwdriver underneath the plastic cup touching the metal prongs inside the plastic cup and hold the other screwdriver on the grey painted surface of the screen. Touch the metal parts of the screwdriver together and hold them there for at least 30 seconds. Slide your fingers underneath the plastic cup and pull it away from the tube. Check the 2 metal prongs for any sign of damage and if they are both OK then place them back in the hole making sure that the 2 prongs do not touch when they are in. Press the plastic cup gently, put the cover back on the monitor and then turn it on. If it continues to hiss and pop then it might be a problem with the LOPT its self which will need to be sent in for servicing to change it. Hopefully this advice will help and you wont kill yourself.

Jed.

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