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Nanao-MS8FSG Washed Out/no brightness adjust

bbickell

bbickell

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Stillwater OK
Hey guys, just rotated my Astro City this afternoon into vert from horizontal and now after I've got everything back up I've got a very washed out picture.

I can adjust screen down, but eventually rather than an all-black I just get a cloudy white. I can't get this thing to make a real black for anything right now. I've tried adjusting the brightness on the remote board, but it doesn't seem to make any difference all. I know how the contrast on this monitor is a bit weird, and it is a combo of the R/G/B bias so i can't adjust it directly.

The chassis was rebuilt by PNL about a year ago and everything was working fine up until I rotated it, so I can't quite figure out what I've done. Still gets a picture, just seems to have lost some sharpness and is washed out.

Any suggestions?
 
I haven't tried adjusting the R/G/B bias and seeing if I can bring it in yet, because it's in the cabinet and tough for me to get in and out.

It can't be common to see big adjustments to calibration because a monitor has been rotated, right? I can't spot anything grounding out, or that was disconnected. What I don't get is why lowering screen eventually just goes to a washed out but not dark screen.
 
The monitor should work exactly as it was unless something got messed up.

Recheck all connections over again carefully, and make sure all cabling/connectors are making good contact/are seated properly.

I would suggest rotating it back and see if things change but that would be a pita.
 
I left it as is for a while (off) and came back after dinner and now when I just turned it on it starts making a distinctly electric-clicking sound while it's warming up. It stopped this and finally got a picture, but it looks the same. I turned it right off after it got a picture thinking that this likely wasn't great.

Am I right to think maybe my next step is to discharge it, pull and replace the anode cap and make sure that it's firmly on? I do realize that it's now rotated sideways so maybe gravity, plus movement has loosened it?
 
Discharge it and recheck all connections/ reseat them, make sure they are making good contact, etc... and retest
Also, make sure you didn't short any components in the process, Just double-check what you removed, plugged/unplugged, etc.

Post some pics of your neck board, pot positions, wiring hook ups, etc. If everything is connected properly with good contact, it could be your screen, bias voltages, could also be a short at the crt. So many different things.
 
I would check the wiring harness from the chassis to the remote. The harness on the MS8 is extremely poor and I've had multiple issues with them. You need to check continuity with a meter, eyeballing it won't be enough.
 
I’ve had problems with that harness before where I totally lost blue signal because of a wire out in the connector. I would believe it could be something to do with that smaller green connector on the bias/brightness side.

If someone could tell me a replacement for that cable that is longer I’d just replace it since I’ve had issues before.
 
I'm certainly not great at eyeballing JST connectors yet, but is that a JST-SH that goes to bias/brightness on the remote board? In my head it makes sense that I'm not getting that brightness remote board in the "loop" somehow and since it's a potentiometer wouldn't it's effect be to restrict the brightness? IE, if not connected perhaps that's effectively max brightness?

Sorry if that sounds stupid, just trying to understand monitors better and figure out what to do about the harness since I've already had to bodge the blue wire in a prior thread about this cabinet. Like I said, if I could figure out what standards were on each side and get a new cable that's significantly longer, I'd love to do that.
 
nem said:
I would check the wiring harness from the chassis to the remote. The harness on the MS8 is extremely poor and I've had multiple issues with them. You need to check continuity with a meter, eyeballing it won't be enough.
Click to expand...

I've pulled the monitor, discharged and cleaned around the anode cap and then replaced the anode cap and retried everything. Same overly bright, washed out image.

I get no change when turning the BRIGHT pot on the remote board. This makes me think something is wrong there? Would there be any harm in testing the monitor with the remote board disconnected completely at the chassis to try to determine if it's behaving as if the remote board isn't working?
 
Bro,

Post some Good Pics / Video of what you are working with would go a long way towards helping you troubleshoot things on your end. (Chassis, harness, remote board, connections, etc...)

Could be anything a simple as a pin not making a good connection, to a bad high voltage screen capacitors, to a shorted tube, etc...
 
bbickell said:
Would there be any harm in testing the monitor with the remote board disconnected completely at the chassis to try to determine if it's behaving as if the remote board isn't working?
Click to expand...

Don't do this. It's a bad idea.

Check continuity between the remote and the chassis.
 
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I’ve pulled the remote board to check continuity and I can visually spot one wire pulled out of the connector on the remote board side.

This is pin 11 on the remote board and as well as I can trace it goes to one leg of the SS Switch SW502. If you look at the other side you can spot my original bodge to fix the blue gain wire that was broke when I received the monitor from KC.

This wire is pretty brittle feeling, and I don’t really have good means to clear the connectors and try to re-punch this. I’ll get to continuity testing the rest of the connectors, but if I’d be happier replacing the cable instead of putting it back in the cab.
 
Just tested each connector and I get no continuity across pins 9, 10, 11. This was probably caused by me snagging it while trying to rotate the monitor, if I had to guess since you have to grab the bottom (where the remote board is located) to move the monitor and it's easy to accidentally snag some cable with it and crush it.

I've ordered a 1 foot cable with JST-SH/SR on both ends that should allow me to test if this resolves me problem, but will be too short to button everything back up with the remote board in it's original location.

If that solves my problem I'll still have the challenge of finding a longer one of these cables.
 
Well, I've learned a few things since I last posted. I found out my cable does NOT have SH/SR ends on it, but has PH ends on it.

I also learned that it is actually connector to connector-reversed. I plugged it in first with a connector to connector cable from the R/G/B/bright section of the remote board to the chassis. I then got a grey image (no color) with raster lines. I realized that this didn't look right on the connectors and re-made my cable to be connector to connector-reversed and tested the cable with a multi for continuity.

Now I get no image, just raster lines. I'm afraid I've hosed something on the chassis perhaps (again). Tested with a few devices to make sure it wasn't a problem with my MiSTer. Tried with 2 MiSTers and a 16-in-1 board.

No colors, no sync seem to be detected by the monitor. Just grey image, white raster lines.
 
There is a 4.7 ohm fuse resistor just near the flyback, check if this is ok, you have an issue with 200v line to the neck board. Start checking this resistor
 
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