K7901 - 25 min run then dark (not blank)

Shift_ME

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Hoping someone here can shed some light on the issue I'm having
I power up the monitor, works great, great picture, and continues to run no issue for about 25 min. then the screen foes dark, like the brightness is turned low. If I power off and back on just the monitor its perfect again.

any thoughts?
 
Does it do it suddenly or does it drift into complete dark? Has the chassis been recapped? Because it sounds like that your flyback (screen adjustment) is drifting on you.
 
no has not been recapped, seems to be a gradual fade takes about 5 seconds, but itf I pull the repower the monitor have the safety switches that I just push in or pull out to re-engage the monitor, it comes back full power.

you think its cap related?
 
no has not been recapped, seems to be a gradual fade takes about 5 seconds, but itf I pull the repower the monitor have the safety switches that I just push in or pull out to re-engage the monitor, it comes back full power.

you think its cap related?

i would say flyback and if you have not done a cap kit then definitely do that too. if you need i stock the top quality 100% nichicon 105c cap kits and flybacks.
 
heater resistor on the neckboard R213, those solder joints can break.

if you're able to knock on the metal frame with a screwdriver and get the picture back its probably that. if you watch the orange neck glow fade out it could be that.

alternatively, it could be the flyback, that's where the heater voltage is provided. I would bank on cracked solder joints there though.

the cap kit won't help this, but K7000s always should get them. there's a number of problematic parts locations on these that the solder must be reflowed.
 
yeah I need a few cap kits, I have about 8 monitors in the garage and two in machines that could use them :-s

just resoldered the neck board and running down the clock. wish me luck :)
 
yeah I need a few cap kits, I have about 8 monitors in the garage and two in machines that could use them :-s

just resoldered the neck board and running down the clock. wish me luck :)

if you need any i don't have on my site yet let me know because i only have about 50 kits on my site but have done many others that i am slowly adding.
 
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