Sony GDM-F500 really blurry 1

[haslo]

I have bought a Sony GDM-F500 21' screen second hand via Ricardo about a year ago. It worked perfectly for the first few months, but then started to twitch randomly into being really blurry, a gaussian blur effect. This renders the monitor virtually unusable, since the blur is so strong it also renders text unreadable. The two horizontal lines from the Trinitron wires are still visible. Funny enough, the screen randomly switches back into its sharp state for some time (some seconds up to several hours), before going to blur again.

Since the monitor was manufactured in 1998, i have no warranty on it anymore. I opened up the monitor case to see if there are any lose connections, but there are none, as far as I can see, and my technical knowledge is too limited to spot anything else that is not as it should be.

I think the cause was that I had it on very high contrast settings for extended periods of time...

Does anybody have any idea if I can fix this on my own? Having the monitor repaired by Sony is not really an option, I guess, I don't think that would cost less than a new monitor...

haslo@haslo.ch - www.haslo.ch​

 

[paparazi]

Nearly all monitors have internal focus adjustment via a screw pot, I guess it's possible that this potentiometer's actual physical internal connections have become tarnished and require working back and forth to make a good connection again.
WARNING* extremely high internal voltages.
look for a "focus" adjustment screw.
Martin


We like members to GIVE and not just TAKE.
Participate and help others.

 

[buchacho]

I have a similar problem with this monitor except that the monitor's image starts out fine and then ramdomly gets blurry (after 20-30 min). If I turn it off for a couple of seconds and the turn the monitor back on, the image returns to normal. Would the solution provided by Paparazi work in this instance too? What does "working back and forth" mean exactly?

Thanks,
Thomas

 

[haslo]

Paparazi's solution unfortunately did not work for me - I had tried that already before, there are actually 3 potentiometers, but none of them seems to be the cause of the problem.

I have received a mail from somebody later on. The contents being:

I have the same monitor as you GDM F500 and surprisingly enough made in the same year 1998. I replaced a Module call the High Voltage Resistor which is used to focus the screen, 2 years age and it’s work since them till now, gone again. The monitor started to crackle sound like High Voltage leak, and then went out of focus as it did 2 years before. I purchase the same module again last week and this time the problem still persists. Works for 20 to 30 minutes then out of focus. Sorry to say when it is out of focus adjusting the module does not get it as sharp as it is suppose to be. I will be looking at this further. I did give Sony Service a call and was told they have never seen that problem RIGHT no freaking help. I did purchase a used CDP-G500 made in the year 2000 last week and it’s not bad at all, similar to the GDM F500 in spec but .24 dot pitch instead of .22, considering I bought it for $200 Canadian and the convergence is excellent. The Module by the way cost $73.00 Sony Part Number 1-453-271-11 Resister Assembly is the description on the packaging.

This sounds very reasonable to me. I haven't tried it as well though. One of the reasons being I'm in europe and getting spare parts from Sony is incredibly difficult here (I tried with a notebook keyboard once, their support just plain sucks if you're not inside their warranty time anymore), and the other being that I see no sense in spending money if it will break later on again anyways.

However, buchacho, my monitor started out like this as well - just blurring after some time on, and when switched off and then on again the image is crisp again. It will get worse over time though, trust me...

haslo@haslo.ch - www.haslo.ch​

 

[micker377]

From:

http://www.anatekcorp.com/faq/monitor.htm

QUESTION NO. P33103-3: Sony GDMF500 monitor with drifting focus and intermittent retrace, all main supply voltages checked ok, suspect focus divider.
Before replacing the CP701 focus module, rule out if the CRT has an internal leak-path, which may occur in this model. Detach the CRT board from the CRT, and check with a high-voltage probe, to see if any voltage is leaking into the CRT's focus pins, etc, while under power. If any voltage is seen on the CRT pins while the CRT board is removed, there is an internal leak-path in the CRT.

Kind of complicated. Looks like Sony repair or new monitor.

 

[haslo]

Thanks for posting. New monitor it was for me, I'm very happy with my Samsung SyncMaster 710N now...

haslo@haslo.ch - www.haslo.ch​

 

[buchacho]

Haslo,

This may be a site to check out:

http://www.pagel.net/monitor/

How long did it take for the problem to become permanent?

 

[haslo]

Oh, that site looks great I'll give that semiconductor a try then. And 3 Bucks is something I want to spend on that monitor...

For me, it took about half a year. I must admit that I didn't give the monitor the best treatment though - I live in a small apartement, with very restricted space, and after it didn't work anymore (the blur had become more and more regular over the period of about 2 months) had put the monitor in the attic. So, probably, if you treat it better it won't break at all.

haslo@haslo.ch - www.haslo.ch​