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Nanao MS8-29FSG "fixed" but now with new problems

notsonic

notsonic

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I have a Nano MS8 that has been giving me problems for a little while and has finally given up completely.

At first it would turn on and immediately turn off. If I kept trying it would eventually stay on.

That stopped working, and the next trick was to leave it powered on for a while and then quickly turn it off and on.

The last time I tried this, I left it on for a while (I forgot it was on) and eventually a garbled picture came up. And now it seems like, pretty reliably, this garbled picture state will come up. It does not have the signature high pitched whine it used to have when working correctly.

I'm most likely going to send this to someone for repair (if anyone has any recommendations I'd appreciate it) unless this happens to be super common and all you gotta do is replace this one easy part.
 

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That looks like an issue with horizontal sync, but given the gradual worsening of performance there's clearly more going on.

Common problems with monitors are electrolytic capacitors and cold solder joints, and if the caps haven't been replaced and solder joints haven't been gone over, that's a maintenance point to start.

If you've never done monitor or general electronics repair, and you don't have the proper tools or experience, you can learn but understand you are likely to make things worse when you're just starting out. Be prepared to send it in for repair or buy a new monitor chassis.

The two repair shops I see mentioned most often are:

https://sharpimagerepair.com/
http://www.pnlvideo.com/
 
I don't think its a sync issue, at least not primarily, since there's a lot more going on. The image is dim and not full height or width, and there's no high pitched whine anymore, which makes me think there's something wrong with the high voltage.

I'm relatively comfortable working on electronics, but I've mostly kept away from working on CRTs. I'll reach out to repair places and keep the thread updated.
 
I got my chassis back from PNL today and it seems like it's mostly working. I have had some problems though.

1. 3 times it shut off right when powered on but it hasn't for a few more power ons since.
2. It seems to have high pitched whines that come and go, not directly related to what's on screen.
3. Every once and a while the picture jumps up and down, but i think this is related to the remote board.

And finally, the big one. Something just doesn't look right with the picture. I spent about an hour twiddling the remote board knobs and I think I just need to pull it back out and adjust it properly with the other knobs on the chassis. It kind of looks like when you turn up the sharpness on a consumer crt (the sharpness switch is off on the remote board) like there's extra detail on the edges and beyond the edges of things. Third Strike looks exceptionally bad. Maybe it's convergence?

The test grid from third strike looks like this (ignore the speckles, I should have turned off my Christmas lights):
PXL_20220129_013718016.jpg
And some in game screens:
PXL_20220129_013655544.jpg PXL_20220129_013637993.jpgPXL_20220129_012616680.jpgPXL_20220129_012607853.jpg
 
There's a switch on the remote, S.S. It's for 'enhancing sharpness'. It is terrible and should always be turned off. Try pressing it.

Also, it could be just your pic, but your focus looks out of whack. Adjust that from the flyback.
 
I have the SS switch off in those pics.

I spent a few hours diddling the knobs last night, including convergence rings. The bottom left corner definitely has a convergence problem but I think I have the picture dialed in.

PXL_20220129_054700157.jpg

I'll take some test pattern pics later today when I put it all back together again.
 
Just note that PNL may have fixed your major issue with garbled graphics, but I am almost certain they did not recap the chassis for preventative maintenance. Also if PNL does change out some caps, they use the cheapest Chinese knockoffs. Not trying to hate on PNL, because they brought back numerous chassis boards from the dead for me. I am just giving you a heads up from experience.

Recapping may help with picture stability. Those caps on that MS8 are probably all original from 30 years ago, so it would be good to change those out later down the road.
 
Yeah for sure. I think the majority of that was the focus. But I really had to dial it in with the RGB controls, screen, and brightness first to get the focus to look right. It's like it would be blurry, correct, or like over correct to the point where it looked like the pixels breaking up.

I got some convergence strips on order to fix up the bottom left corner and hopefully that'll be that.
 
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I got a 100v step down converter (my house voltage is 125v, converter output is 107v) to see if it did anything. I was hoping it would help with the monitor instantly shutting off on cold start. It did not. It also did not seem to have any effect on the picture or various noises the monitor makes. The only thing that did happen is my marquee light stopped working. So I just plugged it back into the wall.

I got the convergence strips in the mail, I'm just waiting on my Wheaties to kick in to feel like pulling the monitor back out.
 
notsonic said:
I got my chassis back from PNL today and it seems like it's mostly working. I have had some problems though.

1. 3 times it shut off right when powered on but it hasn't for a few more power ons since.
2. It seems to have high pitched whines that come and go, not directly related to what's on screen.
3. Every once and a while the picture jumps up and down, but i think this is related to the remote board.

And finally, the big one. Something just doesn't look right with the picture. I spent about an hour twiddling the remote board knobs and I think I just need to pull it back out and adjust it properly with the other knobs on the chassis. It kind of looks like when you turn up the sharpness on a consumer crt (the sharpness switch is off on the remote board) like there's extra detail on the edges and beyond the edges of things. Third Strike looks exceptionally bad. Maybe it's convergence?

The test grid from third strike looks like this (ignore the speckles, I should have turned off my Christmas lights):
PXL_20220129_013718016.jpg
And some in game screens:
PXL_20220129_013655544.jpg PXL_20220129_013637993.jpgPXL_20220129_012616680.jpgPXL_20220129_012607853.jpg
Click to expand...
I have pretty much this same issue. I dont get how you are supposed to make the adjustments on the side of the chassis while its turned on. I think mine is convergence, plus everything seems to have a yellow tint to it. Did you ever mess with the chassis asjustments? I did the ones on the flyback but not the side.
 
I gave up on the MS8 and am using a different MS2931 for now until I swap the MS8's tube to an MS9 yoke and chassis.
 
You are using an MS2931 with the original tube?

Yeah I’m at the point where I just want an MS-9 in there.

I ordered another Ms-8 tube and chassis that I will test first.

Curious what most ppl who own an Astro 2 or MS-8 have switched to or have encountered this issue
 
Sorry, I had an entire spare MS2931 (tube + chassis) from a Blast City that I swapped into my Astro for the time being.

I stopped using the MS8 because I could never get the convergence right, even after dropping the entire tube and chassis off with a local repair guy. In addition, it still shuts off randomly and doesn't always turn on. One thing that helped a little, specifically to reduce ghosting/ringing on CPS3 was to add resistors in line with the RGB and Sync. There's a thread about it somewhere. I think the MS8 is best paired with older/lower resolution games.
 
When you get the MS9 yoke and chassis, shoot me a DM--I'll take the MS8 yoke and chassis off your hands :)
 
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