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Astro City monitor nanao ms8 no blue signal

I mean the tube should be fine assuming the anode cap wasn't like laying on the neck or something.

As for what goes on a chassis when you don't plug the anode cap in before turning it on: I'm not certain. I just know you're really not supposed to.
 
Image looks incredibly washed out and when I don't have a source the raster lines are very bright. It's like "black" is gone, for lack of a better word, and I can't really make out any color. Uh, and it's super out of focus and blurry.

I've torched this chassis, haven't I?
 
bbickell said:
I've torched this chassis, haven't I?
Click to expand...
Maybe.

Let's wait for someone else to chime in before assuming the worst.

I assume that SCREEN and FOCUS are useless now?

And out of curiosity: where was the anode wire?
 
Anode cup was resting near the top of the tube, no metal was touching anything, but I'm sure that kind of voltage could potentially arc.

I will test screen and focus.
 
Monitor does react to screen and focus adjustments. Got it un-blurry to some degree but now if I lower SCREEN it goes blurry and if I raise SCREEN I can get focus but my blacks are washed out. If I raise screen further, I start to get a clicking. If I lower it, I loose focus.

I wonder if I have just damaged the fly-back?

Are SCREEN and FOCUS adjustments on the flyback, or the chassis? I'm not sure how to call these parts exactly.
 
@bbickell they're on the flyback. It's the big black kinda canister shaped thing with pots and the anode wire coming out of it.
 
First thing I would do is smell around for burnt capactiors on the chassis.

Look for brown marks around capcitor legs, Bulging, Leaking electrolitic fluid. Hopefully something pops out in front of you.

On a side note. How do you take animated gif pics?

I notcied them in your imgur
 
hoagtech said:
First thing I would do is smell around for burnt capactiors on the chassis.

Look for brown marks around capcitor legs, Bulging, Leaking electrolitic fluid. Hopefully something pops out in front of you.

On a side note. How do you take animated gif pics?

I notcied them in your imgur
Click to expand...
I'll take a look and see what I come up with. Nothing jumps out at me right now, but I've got it powered down and discharged. I'll poke around at it.

As for the animated gif - that's just a "live" photo from an iPhone 11 posted in the imgur app. Seems to do a better job capturing monitors so you don't get a sync line right in the middle.

Even though I am in fact a complete newb idiot, I am feeling somewhat better that the tube is likely undamaged, and that the damage to the chassis seems manageable, whatever it is, given that all of my geometry, convergence etc seems ok - it's just that screen/focus adjustments seem pretty busted.
 
There are a couple of things, but if you are getting anything on-screen then that's better than it could be. That same situation has lead to dead chassis for others in the past.

I think it's a very low chance your tube got damaged, but it's not impossible. I wonder if the HV divider, responsible for both screen and focus voltages, could have been damaged. That's not fixable, and not measurable without proper equipment.

It is not too hard to find an MS8-29 that's broken to salvage a flyback off of, though. That might be a good course of action.

If you find an MS8-29FN22, a later variant, then I'd say just use that chassis and never let the other type back into your house!


As for the cap, it looks fine. That looks as if it is just factory goop to hold it in place (with its neighboring cap having been replaced, though, it does nothing).
 
Is salvaging a flyback from another chassis the best route, or is there a replacement component I could look for?

The current behavior I’m observing is that if I lower SCREEN any more than it is in the prior photos, I lose my picture and it goes to a grey/white almost blank screen. I don’t know if that’s normal behavior when lowering SCREEN or not.

All indications from other monitor calibration articles I’ve seen is that lowering SCREEN should produce an all black absence of image.


Or could this indicate that the pots on the flyback are hosed?
 
Yeah, what I thought might be damage was just weird lighting.
 
I have tracked down what based on the picture and comparison with my chassis looks to be the exact same unit, including neck board and remote adjustments which seems to be a give away that it’s a 29FSG. Seller indicates that it’s sold untested for parts/repair.

Is that about how this goes? Snag a few and hope I find the working parts I need?
 
Well, for those playing along at home I think I’m going to end up boxing the chassis, neck board and remote board up and sending it to PNL. I just had a nice conversation with John over there about how stupid I am (my words not his). He made me feel a lot less stupid and thought that he could fix whatever I’ve destroyed.

I suspect I’ll feel better about that, even if I spend some money, than trying to buy parts chassis’s from eBay and not having to skill to work on it myself.
 
Glad you're getting it sorted, no matter what direction you're headed in.

We've all made really stupid mistakes at one point or another. Live and learn.

Least you didn't get shocked. I've done that one.
 
Yeah I told my wife as much - hey at least it was a mistake with high voltage that didn’t kill me. That’s not too bad!

I am going to be much more certain of where an anode cap is at all times before powering a monitor on now.

What’s probably the most annoying is that I just tracked that blue signal issue down and had finished cleaning this Astro City and was getting ready to put the monitor back in when I torched it.
 
@bbickell Yeah, you were on top of things, and it was all coming together. Small mistake doesn't change that. Still doing great for being new to this, and willing to do more than most!
 
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