What's new
By:
Filters

Nanao MS-2933 Issue after taking it in for Repair at PNL

incase anyone needs to know this is basically the block of caps your looking at for vertical. Around the vertical IC.

There is also a red mylar cap in front of the output Ic may be out of spec (odd for a mylar but I have seen it)

1711488372842.png
 
Unfortunately, after a couple months, my monitor is starting to curl. It only happens after about 10 minutes of playing. It only happens on 31khz. I’ve yet to test the 15khz mode. But if I reset it, it will be fine until it’s on for another 10 minutes.

I will reach out to John again at PNL, but was wondering if this is a cap that I can fix? Apparently, John replaced EVERY cap on the chassis.
 

Attachments

  • IMG_7870.jpeg
    IMG_7870.jpeg
    339.5 KB · Views: 49
  • IMG_7869.jpeg
    IMG_7869.jpeg
    379.1 KB · Views: 50
  • IMG_7868.jpeg
    IMG_7868.jpeg
    337.1 KB · Views: 51
  • IMG_7856.jpeg
    IMG_7856.jpeg
    199.4 KB · Views: 54
  • IMG_7858.jpeg
    IMG_7858.jpeg
    180.6 KB · Views: 57
  • IMG_7862.jpeg
    IMG_7862.jpeg
    157.7 KB · Views: 53
  • IMG_7860.jpeg
    IMG_7860.jpeg
    251.9 KB · Views: 50
  • IMG_7859.jpeg
    IMG_7859.jpeg
    231.4 KB · Views: 54
  • IMG_7863.jpeg
    IMG_7863.jpeg
    239.9 KB · Views: 47
With what you've spent and will continue to spend sending this off to John, I'd recommend getting a working chasiss at this point. Don't wanna risk that chassis failing and taking out the tube. Then you'll have a nice paper weight Blast unless you have a spare tube, access to a spare tube off a game or a D9200 handy.
 
I agree send it back for an inspection again. This is having to do with vertical drive circuits in some capacity. Usually its a capacitor that causes curl but could be a passive could be the actual IC.

I wouldnt worry about the tube being taken out from this. This doesnt look like a HV issue. The reason the tubes die on these is if the flyback is failing and shorts theres a CHANCE that the shutdown circuit doesnt catch the short and shut down fast enough. The HV ramps up too high and it arcs internally into the gun of the tube. Killing the tube and the heat usually cracks the neck.
Rare occurance but it deals with failing flybacks and HV not geo deflection circuits.

However I also would not really continue to run it like that for longer than needed to test stuff because it could be stressing other parts out in the drive deflection or drive.
 
GeekMan1222 said:
I agree send it back for an inspection again. This is having to do with vertical drive circuits in some capacity. Usually its a capacitor that causes curl but could be a passive could be the actual IC.

I wouldnt worry about the tube being taken out from this. This doesnt look like a HV issue. The reason the tubes die on these is if the flyback is failing and shorts theres a CHANCE that the shutdown circuit doesnt catch the short and shut down fast enough. The HV ramps up too high and it arcs internally into the gun of the tube. Killing the tube and the heat usually cracks the neck.
Rare occurance but it deals with failing flybacks and HV not geo deflection circuits.

However I also would not really continue to run it like that for longer than needed to test stuff because it could be stressing other parts out in the drive deflection or drive.
Click to expand...
I went back to John and he pulled the flyback and chassis from my monitor. He's gonna work on it for a few weeks. I'll keep you posted.
 
I had over a year of back-and-forth with a 2933 and PNL.
  • Tube was bad. Replaced that.
  • Chassis was recapped. But ended up an IC chip was bad. Replaced with a 2931 chassis.
  • 2931 was having issues. Recapped.
  • During this time was able to get a nice, working, 2930 from @garou81 (thank you again!)
  • Flyback ended up being bad. Replaced that.
  • Now it's a beautiful spare monitor.
PNL did a great job. But it was also rough for me to keep going out to Covina.
 
IMG_0760.jpeg


Apologies for the late response.

John was able to do a bunch of extensive testing as it kept randomly vertical folding due to temperature. He was able to fix the chassis and do overnight tests to make sure the folding stopped. He also did some preemptive repair work on the flyback. All with no extra charges!
He did so much work and spent a lot of time, I offered to do some web marketing for him in return.

Due to his place being burned down, he had to move to a new location. However, he didn’t know how to update his information online (google, yelp, pnlvideo.com).

It took some time to get his accounts verified, but now his site and online address are now updated!

He’s now repairing monitors for fun as he’s pretty much retired. Try to visit in person if you have the chance before he leaves the business for good.
 

Attachments

  • IMG_0842.jpeg
    IMG_0842.jpeg
    198.7 KB · Views: 68
  • IMG_0841.png
    IMG_0841.png
    667.3 KB · Views: 67
  • IMG_0795.png
    IMG_0795.png
    191.2 KB · Views: 77
  • IMG_0587.jpeg
    IMG_0587.jpeg
    248.4 KB · Views: 78
  • IMG_0605.jpeg
    IMG_0605.jpeg
    276.1 KB · Views: 84
  • IMG_0611.jpeg
    IMG_0611.jpeg
    199 KB · Views: 80
I also had this exact problem with the twisting of the monitor (MS9 Nanao). After warming up (10 minutes), it was displayed normally.
I changed capacitors, diodes several times, still the same problem.
I couldn't find any information on the Internet.
I didn't like this for a long time..
In the end, it was such a banal problem.
Bad connection LA 7837.
The multimeter always reported a correct connection to IC LA7837 even when it was bad.
That's why the conductivity probably improved after warming up and the monitor then worked properly
If you have this problem, try to connect with a cable, each suspect connection of the Vertical IC.
 
tacobell said:
IMG_0760.jpeg


Apologies for the late response.

John was able to do a bunch of extensive testing as it kept randomly vertical folding due to temperature. He was able to fix the chassis and do overnight tests to make sure the folding stopped. He also did some preemptive repair work on the flyback. All with no extra charges!
He did so much work and spent a lot of time, I offered to do some web marketing for him in return.

Due to his place being burned down, he had to move to a new location. However, he didn’t know how to update his information online (google, yelp, pnlvideo.com).

It took some time to get his accounts verified, but now his site and online address are now updated!

He’s now repairing monitors for fun as he’s pretty much retired. Try to visit in person if you have the chance before he leaves the business for good.
Click to expand...
glad its fixed. I wonder if he would post info on his site for various failures and fixes hes tackled over the years. A lot of business will fix and never tell you the “fix” to keep business coming back, but now is a good time to extract and share knowledge if hes hanging up the profit side of things.
 
advans14 said:
glad its fixed. I wonder if he would post info on his site for various failures and fixes hes tackled over the years. A lot of business will fix and never tell you the “fix” to keep business coming back, but now is a good time to extract and share knowledge if hes hanging up the profit side of things.
Click to expand...
This. Last time I had a chassis serviced (Elvis at Sharp Image) 3 or so years ago, I asked for any replaced components to be returned with the chassis. He did that. Obviously this doesn't tell you everything but at least I knew what component was bad and could infer pseudo-diagnosis from that.
 
advans14 said:
glad its fixed. I wonder if he would post info on his site for various failures and fixes hes tackled over the years. A lot of business will fix and never tell you the “fix” to keep business coming back, but now is a good time to extract and share knowledge if hes hanging up the profit side of things.
Click to expand...
I respect if it dies with him. Og azn right here.
 
I respect your opinion just solely on your username. Respect the bell
 
Just got this back again from John at PNL. Ran a 24 hour test and it’s pretty stable now. No vertical folding!
IMG_1950.jpeg


So when I got it back in October, it was running fine for a couple days. Unfortunately, it folded again after running the machine for about 2 hours:
IMG_1398.jpeg


It would fix itself after a restart but come back eventually and exponentially. Next time it came back was an hour, followed by 15 min, then as soon as it turned on.

At first he thought there wasn’t anything wrong since it played fine when he received it. However, when he ran it for about 4 hours, it started to fold.

We originally thought it was temperature based as it was a bit colder now and it took some time for the issue to show up. He reviewed IC LA 7846 with the oscilloscope on the chassis and that was the issue. He replaced it and ran the monitor for 8 hours straight with no folding.

Hopefully, this will last for many years to come. Now, onto the other monitor…
 
You must log in or register to reply here.
Back
Top