BVM-20E1U "Micro" Vertical Shake Help

[DatPhosphorGlow]

I've made a video to help explain the issue I'm having with a BVM-20E1U.

The picture seems to have "micro" shakes vertically.

Camera was placed on a tripod, set to manual focus, and countdown timer to start the recording. The shake you are seeing is not camera shake, except for the last 2 second of video where I need to press the shutter to end the recording.

Any ideas what could be causing this?

The sync isn't pure as it's an unmodified 1CHIP-03 SNES and I'm borrowing a friend's N64 scart cable to test, so I'm assuming it's sync on luma, maybe sync on composite.

The reason I do not think it's a sync issue is that when I connect a composite source to the monitor the shake is still there. Also, when I hook up the exact same setup to my BVM-D14H1U there is no shake. I have a non 1CHIP-03 SNES and CSYNC cables on the way.

Is it possible the non D BVMs are more sensitive with SYNC signals than the newer D series? If so, then why do I get a shake with a composite source on the 20E1U?

Here's the video:

https://www.youtube.com/watch?v=UBIfJfV ... e=youtu.be

[andy251203]

This is a known issue with your series of BVM.

I have had 5 or 6 BVM-20F1Us that all have this behavior. I am convinced it is a design flaw with the deflection board. I do not think replacing capacitors will fix it. I have a pristine BVM-14F5U with less than 3000 hours on it, and it still has this issue, albeit not as bad as yours.

I want to say it may be because the monitor is not designed to handle 240p, but I think the shaking is still there for a 480i image, just less noticeable.

I ended up selling all of my 20F1Us because of this. I would get a headache after an hour of viewing. The people I sold to didn't notice the issue or didn't care.

FYI, the BVM-D series does not have this issue.

[22point8]

Have you tried the AFC setting?

[DatPhosphorGlow]

Have you tried the AFC setting?

Just tried that, still shakes. It was set to "SLOW", I tried "FAST".

[DatPhosphorGlow]

This is a known issue with your series of BVM.

I have had 5 or 6 BVM-20F1Us that all have this behavior. I am convinced it is a design flaw with the deflection board. I do not think replacing capacitors will fix it. I have a pristine BVM-14F5U with less than 3000 hours on it, and it still has this issue, albeit not as bad as yours.

I want to say it may be because the monitor is not designed to handle 240p, but I think the shaking is still there for a 480i image, just less noticeable.

I ended up selling all of my 20F1Us because of this. I would get a headache after an hour of viewing. The people I sold to didn't notice the issue or didn't care.

FYI, the BVM-D series does not have this issue.

This is the first I'm hearing of it, thanks for your input. How many D20 monitors have you tested that do not have this issue? Have you ever experienced a D series that does shake like so?

Can you elaborate on why/how the monitor is not designed to handle 240P? I'll try 480i and see if that makes a difference.

I wonder if all BVMs of that series do this, I find it hard to believe. To be honest though most people don't notice it, I'm just very very anal. The video exaggerates it as it's real close up.

[andy251203]

It's not that the monitor wasn't designed to handle 240P, rather that displaying 240P is not the original intention of the monitor. Your BVM was designed to monitor 480i broadcast video signals. (Remember that 240P is not considered a valid display mode by NTSC; it's just a mode that happens to work with TVs that was used by video games.)

I only have one BVM-D20F1U and a BVM-D24E1U. These don't have the vertical shaking issue at all. Only the BVM-14/20E/F/G1/5U/E/A series has the issue. Like I said, I think it's a design flaw in the deflection board. Even the older BVMs such as the BVM-1910 and the BVM-1911 do not have this issue, and no PVMs have this issue.

FWIW, of the 5 or 6 20F1Us that I had, while all of them had the vertical shaking issue, some of them were not as bad as others. So it may be an issue that gets worse as the monitor ages. How many hours does your BVM have on it? If it has over 100,000 I would consider finding another monitor.

[AndehX]

My G1E has 52000 hours and doesn't show this issue at all...

[DatPhosphorGlow]

It's not that the monitor wasn't designed to handle 240P, rather that displaying 240P is not the original intention of the monitor. Your BVM was designed to monitor 480i broadcast video signals. (Remember that 240P is not considered a valid display mode by NTSC; it's just a mode that happens to work with TVs that was used by video games.)

I only have one BVM-D20F1U and a BVM-D24E1U. These don't have the vertical shaking issue at all. Only the BVM-14/20E/F/G1/5U/E/A series has the issue. Like I said, I think it's a design flaw in the deflection board. Even the older BVMs such as the BVM-1910 and the BVM-1911 do not have this issue, and no PVMs have this issue.

FWIW, of the 5 or 6 20F1Us that I had, while all of them had the vertical shaking issue, some of them were not as bad as others. So it may be an issue that gets worse as the monitor ages. How many hours does your BVM have on it? If it has over 100,000 I would consider finding another monitor.

60K hours, picture is great, way better than my D14 with 50K hours. I have another D14 with 3K hours on the way so I can have a basis for comparison (in terms of just how much better low hour monitors are).

What were the hours of your 20F1Us? Since you've had a somewhat decent sample size, did you notice a direct relationship between hours and vertical shake?

I checked the service manual and it seems the 20E1U does not have a unique part number for the deflection board (same as 20F1U), this is some good news I guess, as the 20E1U is quite rare. I guess I'll try swapping out the deflection board if I can come across one cheap enough, or a whole monitor for parts perhaps. I'm assuming the deflection board is board "E"?

Can something other than the deflection board cause this behavior? I'm going to try and find an experienced CRT tech.

I know a guy looking to possibly unload a D20F1U with 7K hours, but not at all cheap. Reading about your experiences is making me want to pull the trigger and have it done with. It's unfortunate because the 20E1U is my dream monitor as 95% of the stuff I play is 240P. I've patiently waited a long time to find one. I have no interest in the D24 as the 4:3 picture is a good deal smaller (in my opinion), and the D32 is just a pipe dream. Plus, I like the nostalgia of the curved screens.

My G1E has 52000 hours and doesn't show this issue at all...

It can be very hard to see, my video makes it really easy as it's shot in macro. What I initially did to check if my eyes were screwing with me was adjust the vertical picture so that it's very close (about a single scanline) to the top or bottom bezel of the monitor, and then observe the "empty" scan line space to for fluctuations. As I said, no-one noticed it till I point it out to them.

[andy251203]

The D14 is not a real BVM in terms of quality. That's why the picture is not as good as your 20E1U. When the D series came out, the 14s got the shaft. Internally, they are built more like a PVM than a BVM and take the PVM input cards. Even Sony refers to the BVM-D14 as a "viewing monitor" rather than a "mastering monitor". I've picked up 5 D14s last year and all of them had failed. Either a chassis failure or a bad tube.

The deflection board should be the same between the BVM-20E/F/G. The only difference between these monitors is the tube resolution. E=1000 lines, F=900 lines, G=800 lines. Unless you are able to find a brand new deflection board, swapping probably won't make the issue go away.

Actually you make a good point, between the 20F1Us I owned, some with less hours actually had worse jitters. All of mine were between 60000 and 100000 hours.

I'm actually going to speak with a technician about this issue soon. He might have some info about this issue.

[DatPhosphorGlow]

I know replacing the deflection board will not solve the problem as it's highly probable I will get another defective deflection board. However, if it is what's causing the issue I can sort of verify that by seeing if I get different behavior with a different card. If so, I'll attempt to diagnose and repair the deflection board.

It's definitely interesting that your sample of 20F1Us did not have a direct relationship between hours and shake behavior, supports your theory that it's a design flaw.

Let me know what your tech says, I'm still trying to find a local one.