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Sony F500R CRT

A few months ago I located a "new old stock" Sony F500R CRT. It was bought as a spare for a corporation but had never been used since its manufacture date of November 1999.

When I first started using the set, the picture was absolutely perfect, until my nephew decided to see what the "auto restoration" feature was for on the monitor. Zip, zap, the picture flung around and then resettled back down. No harm, or so I thought.

Ever since, when I power on the monitor, the brightness is overdriven and I cannot get a pure black level. If I set the brightness to zero it's pretty close. After about ten minutes the brightness decreases rather rapidly, and I have to manually adjust it back upwards to achieve a proper black level, and it stays fine until it's powered off again, and I have to repeat the same cycle all over again.

My two questions are,

  1. What is the likely cause of this problem? Bad caps, or is there an internal way to reset whatever the "auto restoration" function did?

  1. If the likely problem is bad components, is anyone reading this in the Bay Area of California, and would you like to make some money repairing it for me? I can't say money is no object but I'm willing to pay several hundred in labor costs to get the monitor thoroughly tested and repaired correctly.

Thanks.

Reply to
<nospam
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I don't know what unit this CRT goes with, but I can offer a possible suggestion.

Look on the high voltage transformer assembly, or on the HV multiplier, or on one of the CRT drive circuit boards. Look for an adjustment called CRT bias, or Screen, or G2. Mark the position of the pot so that you can move it back. Try the adjustment.

Jerry G.

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Reply to
Jerry G.

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Hit the reset button on the monitor (after it has warmed up for 30 minutes), then get into the menu and do a auto restore. I think the restore function needs to have the contrast and brightness at a default setting to work sometimes. I had the brightness problem on my 420GS and doing the above steps fixed it.

Reply to
Powermac

If anything, the auto restore should fix any brightness problems, not cause them.

This behavior is normal for Sony monitors. Every single one I've seen starts out overly bright, but settles down after about 10 minutes. When fully warmed up, the brightness should need to be set to around

30 if everything is working correctly. The easiest way to set the brightness is to open a full screen DOS box, and adjust it so that the raster lines in the black area are just slightly visible in a dark room. Andy Cuffe

snipped-for-privacy@gmail.com

Reply to
Andy Cuffe

What's confusing is, my monitor did not behave this way until my nephew did the image restoration function. The monitor never required brightness adjustment.

I tried the reset button/image restore sequence suggested by another poster, it didn't help.

Reply to
<nospam

It's possible that the brightness was low enough that it wasn't noticeable even when it was first turned on. I'm willing to bet that the brightness level ended up being too low once it warmed up. Many people have the brightness set too low, and don't notice the missing shadow detail, or even prefer the high contrast look. Now that it's correctly adjusted, it's too bright when it's cold.

I've worked with dozens of these monitors, and every single one has been noticeably too bright when first turned on. I've seen this problem mentioned on discussion forums too. As long as you can get the correct brightness after warm up, the monitor is working properly. Andy Cuffe

snipped-for-privacy@gmail.com

Reply to
Andy Cuffe

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