optiquest flat screen monitor broke

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paulmars

New Member

• Nov 19, 2009

• #1

model Q7. Screen goes blank after 10-30 minutes. If I turn it off for long enough, it will work again for a while. Sometimes when I turn it back on the image flickers rapidly. I removed the over and the metal shroud over one of the circuit board and set a fan to blow air over it. This did not help.

Ideas?

paul

 

CalebG

New Member

• Nov 21, 2009

• #2

can we see a picture of the flickering?

 

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paulmars

New Member

• Nov 21, 2009

• #3

CalebG said:

can we see a picture of the flickering?

Click to expand...

For that I would have to hook it up and keep turning it on and off over time until I happened again. I dont think seeing the flickering would really help troubleshoot.

 

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picbits

Well-Known Member

• Nov 21, 2009

• #4

Quite often a dried out electrolytic capacitor in the power supply.

If you don't have an ESR meter to test them, just try and replace them - won't cost too much if it doesn't work.

I've fixed three LCD monitors all with the same problems as yours this way and they are all still going strong.

 

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paulmars

New Member

• Nov 21, 2009

• #5

thanks would a picture help identify the most likely cap(s)? Several have slightly bowed tops, which I thought indicated over heating.

 

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picbits

Well-Known Member

• Nov 21, 2009

• #6

Bowed tops = bad

One of my monitors had no bowed caps but they were still knackered - they had dried out and once replaced worked fine.

For the sake of pennies get them replaced and see if it helps. I think a complete set of caps for one of my monitors (from RS who aren't cheap !) were around £3

Don't get cheap caps, get proper low ESR switch mode caps at 105 degrees C and see what happens.

 

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paulmars

New Member

• Nov 21, 2009

• #7

ok, but from RS? When I took electronics in hi school and at the tech center everyone said stay away from RS. Now that was 20+ years ago, but are they actually better now?

 

blueroomelectronics

Well-Known Member

• Nov 21, 2009

• #8

Digikey will have low ESR caps.

 

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picbits

Well-Known Member

• Nov 22, 2009

• #9

RS as in RS Components in the UK not Radioshack in the USA