I built my own 27FV310.

[Ryeno]

Hello everyone. I think this is the right forum to post my build log and guide. I hope you appreciate my work and maybe someone will build their own 27FV310.

Background
The 27FV310 is the best consumer grade television because it has good high voltage regulation to prevent bloom. Bloom is when brighter images expand the raster and dark images shrink the raster. In addition, the TV supports YPbPr inputs, is RGB moddable and has a good gamma curve.

The problem is that this TV is pretty rare because it was released during the switch between SD and HD. So most people skipped it for an HD set. Quite ironic because today HD consumer CRTs are the worst sets. The other issue is that the FV310 was a high-end SKU so if someone was willing to pay the premium over the entry (FS) and mid series (FV300) SKUs, they would likely get the 36" or 32”. For this reason the 27FV310 appears to be rarer than the 36FV310.

The biggest weakness is the geometry tends to be poor on these flatscreen Trinitrons but the quality really varies from yoke to yoke and you can generally find a decent yoke if you bin a few. Quite a few people say to avoid the flatscreen Trinitons because they do have worse geometry on avg than the curved Trinitons and that is true but it really does vary from set to set and if you want great geometry then get a 13”/14” PVM or a BVM. The trade-off for screen size is worse geometry.

With that said, let’s get to the modding.

The Problem
As I said, it’s very hard to find a 27FV310 so I decided to build my own using a 27FS210 donor chassis and 36FV310 circuit boards. You would think that it would be possible to swap the 27” components from the 27” PCBs to the 36” PCBs and you’d be correct but it’s not possible to swap T510. T510 generates the heater voltage and it’s driven by the horizontal deflection circuity so it affects horizontal deflection size and linearity. Luckily it’s pretty simple to compensate for the 36" T510 using a few 36” components.

The Guide

A Board

SWAP:
These caps control the timing so they must all be swapped to adjust from the 32" or 36" to the 27”.

• C511: 17000pF
  C513: 0.047uF
  C514: 0.68uF
  C554: 2700pF
  C553: 0.1uF (from C1501) // Decreasing capacitance from 0.24uF to 0.10uF increased raster size.
  R504: 1k ohm // Transformer inrush current resistor. I recommend upgrading to a 1K 2W resistor
  R526: 4.7 ohm // This resistor separates the pin correction circuit from H drive circuit but it also effects raster size.
  R576: 22 ohm // Horizontal centering resistor.

OPTIONAL SWAP:
These components control pincushion, vertical deflection and over current protection. I swapped these components on my set but I would recommend leaving the 32/’36” values unless you have issues, e.g. pincushion not calibrating properly.

• R501: 330 ohm // I believe this resistor forms a voltage divider with R502. If so decreasing the value of the resistor from 470 to 330 increases the voltage range. I used 330 ohm on my set but I would recommend leaving the value at 470 ohm.
  R516 & R523: 8.2k & 22k // I believe these resistors form a voltage divider. 4.7k & 12k = 6.47v, 8.2k & 22k = 6.56v. .1v difference. Very minor.
  R531: 180k // Possibly a voltage divider with R529 and R530. Regardless it’s parallel with R530 so it’s 12K & 56K = 9.9k, 12K&180k=11.3kohm. I swapped these on my set but I would recommend leaving 56k unless you have problems with pincushion not working,
  R534, R558, R666, R568: 10K & 15k in parallel = 6k // Don’t swap these. The value is close to the 27” 6.8k. Furthermore the 32” uses 5.6k so the pattern isn’t consistent.
  R593: 1k // Didn’t swap. Protection resistor.

DO NOT SWAP:
The components are part of the size adjustment and dummy yoke circuit. I initially swapped these values to the 27” but my raster was too small. I changed these values back to 36” and I was able to get adequate raster size in the service menu and horizontal linearity. Hsiz 59-63 with 2.5% overscan.

• T505: 098 // IIRC using 098 (36FV310) over 850 (27FS210) increased the raster size. 27FV300 has a different part (693).
  T510: 848 // Can’t swap.
  L505 150mH inductor // IIRC increasing inductance from 100mH to 150mH increased the raster size.
  C516 1.2uF // IIRC increasing capacitance from .82uF to 1.2uF improved horizontal linearity..

D Board
This board controls dynamic focus and protection circuits. You probably don’t need to swap any components but it’s a good idea to swap the dynamic focus resistors and capacitors.

SWAP:

• C8512: 3900pF
  C8542: 220pF
  C8850: 680pF
  R8542: 8.2k
  R8554: 8.2k
  R8554: 15k

OPTIONAL SWAP:
These components are all part of the protection circuit and don’t require swapping.

• R8009:
  R8017:
  R8021:
  R8040:
  R8046:
  R8052:

C Board
This board controls the heater voltage. The voltage must be 6.3v+/-.2v. The problem here is that the voltage is AC and runs at 15.7khz. Most multimeters aren’t designed to sample this high frequency. I use a Fluke 189. I think a Fluke 87V would work as well.

SWAP:

• R717:
  R718: 2.2Ohm?

Conclusion
This is a fairly simple conversion once you know what you're doing: you're changing some parts to 27" spec, you're leaving a few parts 36" spec as to compensate for the 36" heater transformer, you're not swapping some parts because they're not required or very similar to 27" spec, and you're measuring heater voltage. So if you're in the unique situation of having both a 27FS210 or 27FV300 and a 32/36FV310, you too can make your own 27FV310. Enjoy.

Pictures

Spoiler

Resources

https://www.slideshare.net/JamesWebb15? ... sslideview
1 _CRT Display Design_ 
2 _CRT Display Design_A_ 
3 _CRT Display Design_A_ 

https://elektrotanya.com/sites/default/ ... BET%5D.pdf

https://twitter.com/turom_/status/1011142753751793666

[Josh128]

What would you suppose is the issue when a TV actually shrinks a bright image a bit and expands a dark image? Power supply or B+ regulation issues? What specifically? I have a very nice Hitachi dual scan that does this, but none of the other units of the same models do.

[Ryeno]

What would you suppose is the issue when a TV actually shrinks a bright image a bit and expands a dark image? Power supply or B+ regulation issues? What specifically? I have a very nice Hitachi dual scan that does this, but none of the other units of the same models do.

You could measure B+ and see if it decreases during a bright image. If it does then probably the issue is in the power supply circuit. If B+ is constant then the issue is likely in the high voltage circuit. You could also buy a high voltage probe and test the high voltage.

[maxtherabbit]

why not just use the 36" FV310? bigger is better mmkay

[bobrocks95]

So you had to sacrifice a 36" set to make a 27" set? Did your geometry really improve that much? I wouldn't call the 36" FV310 common either...

Impressive engineering work of course though.

[Ryeno]

why not just use the 36" FV310? bigger is better mmkay

Technically the 27" has a better tube. M68LNH050X vs A90LPW80X.
https://www.streetdirectory.com/travel_ ... mbers.html
With that said, the 36" has a better yoke.

The 36" is too big IMO. You can't fit in a bedroom and it's very difficult to move: 50kg vs 103kg. IMO the only advantage of the 36" is if you want to play splitscreen with other people but 27" is still very good for 4 plays: 27" = 4 x 13.5", 36" =4 x 18".

[Taiyaki]

This is a really cool thread. I can't handle those huge size crt's either. Even 27 inch really needs two people or one really big strong person. Other than that wish you'd done this to a 24 inch, or even 20 inch model would have been even more practical.

All that being said personally I'd dispense with the high voltage regulator because it takes out a quintessential attribute of CRT technology to me, but otherwise indisputably one of the best CRT's.

The FV series flat Trinitrons in general are simply the best ever made imo.

[tongshadow]

Curved black Trinitrons with component inputs were the best imo, but it seems these high-end FV's were in a class of their own.

[Taiyaki]

Curved black Trinitrons with component inputs were the best imo, but it seems these high-end FV's were in a class of their own.

Those were fantastic too but I prefer horizontally and vertically flat Trinitrons. Nothing compares in terms of picture quality imo, assuming one can deal with the less good out of the box geometry that is.

[fernan1234]

All that being said personally I'd dispense with the high voltage regulator because it takes out a quintessential attribute of CRT technology to me, but otherwise indisputably one of the best CRT's.

Apologies in advance if I misunderstand you, but are you referring to what some people call scanline "bloom" where scanlines displaying brighter colors appear thicker or more intense than with darker colors? That's indeed a nice thing, but different from what the OP refers to which is also often called "bloom" for the whole picture or raster, where the edges of the whole picture grow or shrink depending on the overall brightness of the displayed frame (or field). This kind of bloom is often hidden away in the overscan area though, but is objectively a bad thing and good HV regulation is definitely something desirable in any CRT display, especially for signals that are displayed with some underscan.

[bobrocks95]

Yeah geometry outright changing because some white is on the screen sucks. Play a game with a white speech bubble fading in or out and watch that portion of the screen inflate like a balloon. Very notable upgrade when I got my 32" FV310.

[Ryeno]

Curved black Trinitrons with component inputs were the best imo, but it seems these high-end FV's were in a class of their own.

Those were fantastic too but I prefer horizontally and vertically flat Trinitrons. Nothing compares in terms of picture quality imo, assuming one can deal with the less good out of the box geometry that is.

The overall image quality is better on the late 90s and 00s flatscreen WEGAs vs the curved late 80s and 90s consumer sets. The BA-5D chassis specifically has very nice gamma curves. I think whether one prefers the curved or flat really depends on the games.

Flatscreen WEGAs have 2 common geometry issues:

• 1. Warping in the top and bottom regions. This can be minimized through the HOSC setting and hidden by increasing overscan.
  2. Vertical pincushion aka the famous "WEGA bow". This can be equalized between the bottom and top with the 2 rings on the VM board.

For 3D games, the flatscreens look better because 3D hides minor warping.

For 2D games, conventionally many 2D games output in reduced 224p rather than 240p and so the lower resolution crops the worst area of the WEGAs. So if you find a decent yoke, you could find a flatscreen that plays 2D games well.

IMO, if someone really really wants good geometry. I would recommend sticking with a 13/14" set. Even a lower-end set like a 14N5U has good geometry and better than the 20M2Us that I've seen.

[it290]

• 2. Vertical pincushion aka the famous "WEGA bow". This can be equalized between the bottom and top with the 2 rings on the VM board.

Can you elaborate on this? My set suffers from this and I've been told it requires a yoke adjustment, not familiar with the rings you mention.

[Ryeno]

• 2. Vertical pincushion aka the famous "WEGA bow". This can be equalized between the bottom and top with the 2 rings on the VM board.

Can you elaborate on this? My set suffers from this and I've been told it requires a yoke adjustment, not familiar with the rings you mention.

I wrote this calibration guide.
https://www.retrogameboards.com/t/honey ... log/852/61

Do you see how the horizontal (especially top and bottom) white lines bow upward? That can be fixed or reduced by opening or closing the 2 rings on the VM board of flatscreen trinitons.
https://i.redd.it/ci0071z6lo621.jpg

The vm board is between the neckboard and the yoke and it has 2 rings that you can open or close. Using those rings you can equalize the the bowing between top and bottom. Just make sure to keep the rings symmetric/equally spaced around the horizontal axis.

https://uploads.tapatalk-cdn.com/201708 ... dc6691.jpg

[FinalBaton]

A friend picked up a barely used 24FV310 and I gotta say, it looks pretty damn good. I was impressed, as I had a 36FV300 myself and it didn't seem to have that great contrast and colours, but I think the tube in mine was worn quite a lot.

Only saw PS1 through s-videi on the 24 but it looked damn crisp and the colours popped.

[Taiyaki]

A friend picked up a barely used 24FV310 and I gotta say, it looks pretty damn good. I was impressed, as I had a 36FV300 myself and it didn't seem to have that great contrast and colours, but I think the tube in mine was worn quite a lot.

Only saw PS1 through s-videi on the 24 but it looked damn crisp and the colours popped.

A 24FV310? You sure it wasn't a 27FV310? I didn't know they ever manufactured 24 inch versions of it.

My experience with those was that post calibrated they're near identical except for the 310 having the benefits of the high voltage regulator. Granted the FV300's I picked up were new in box from an oldstock dealer some 7 years ago or so so there was no color fading or worn down contrast at all. Never saw a barely used 310 but that's a great find.

[matt]

Might have been a 24FV300. It uses a completely different chassis from the 27 to 36" FV300/310, so the picture does look different (plus smaller tubes tend to be brighter).

I have one of these, and it's one of my favorite sets. Just the right size and the picture's nice and clean. But as with all Wegas it takes a lot of tweaking to optimize it for games.

[Taiyaki]

Might have been a 24FV300. It uses a completely different chassis from the 27 to 36" FV300/310, so the picture does look different (plus smaller tubes tend to be brighter).

I have one of these, and it's one of my favorite sets. Just the right size and the picture's nice and clean. But as with all Wegas it takes a lot of tweaking to optimize it for games.

I second that opinion. The 20/24 inch versions of the FV300 are my favorite versions. Just like the bigger ones it does take some internal tweaking to get right, but frankly I'd say they're the nicest consumer CRT's I've ever seen.

[FinalBaton]

A 24FV310? You sure it wasn't a 27FV310? I didn't know they ever manufactured 24 inch versions of it.

My experience with those was that post calibrated they're near identical except for the 310 having the benefits of the high voltage regulator. Granted the FV300's I picked up were new in box from an oldstock dealer some 7 years ago or so so there was no color fading or worn down contrast at all. Never saw a barely used 310 but that's a great find.

Yep it's a 24FV310, saw the model number on the back label myself.

And indeed it's got a different chassis part number than the 27FV310-to-36FV310.


I gotta say, I've very rarely seen the 24FV310. This was the first time I saw one with my own eyes, and I've seen one or two others max on local classifieds/FB marketplace/what have you.

[matt]

Sony didn't make TVs smaller than 27" with the FV310 label. You must be thinking of the 24FV300.

The smaller size FV300s are pretty rare, for good reason. They're basically the same TV as the FS100, but the price point was significantly higher. I don't think they sold very well.

[Ryeno]

Sony didn't make TVs smaller than 27" with the FV310 label. You must be thinking of the 24FV300.

The smaller size FV300s are pretty rare, for good reason. They're basically the same TV as the FS100, but the price point was significantly higher. I don't think they sold very well.

Actually they're the same as the FS120.

There are 3 (or 4) flatscreen chassis: BA-5 (27FS13, 27FV17), BA-5D (27FS100, 27FV310), and BA-6 (27FS120, 20FV300). You can argue 4 if you consider the FV310 a separate chassis.

The BA-5 and BA-5D chassis have separate jungle chips while the BA-6 has a combined micon and jungle chip. IIRC the image quality was slightly lower on the BA-6 chassis. Also the BA-6 Chassis don't fully disable VM even at 0, IIRC. So you must manually 0 out VM in the service menu or disconnect the neckboard. BA-5D has better gamma curve than BA-5.

[matt]

The 24FS120 is similar, but it was a couple of years later and had a couple of minor upgrades from the FS100/FV300 (most notably 16:9 mode). Personally, I prefer the earlier models because the case design of the FS120 is difficult to TATE.

BA-5/5D both seem to have better gamma than the BA-6, and slightly less pixel jitter. On the other hand, BA-5/5D component video has some weird artifacts and really needs an RGB mod to look its best. Chroma doesn't quite line up properly and there doesn't seem to be a perfect setting for sharpness. BA-6 seems to have a cleaner picture with YPbPr as long as the TV is adjusted well.

There are a few other flat Sony chassis. BA-4C (20FV10), AA-2U (36FS12), and maybe a couple others.

[Taiyaki]

Sony didn't make TVs smaller than 27" with the FV310 label. You must be thinking of the 24FV300.

The smaller size FV300s are pretty rare, for good reason. They're basically the same TV as the FS100, but the price point was significantly higher. I don't think they sold very well.

Having had many FS100's and FS120's of 20/24 inch models as well as FV300's of the same sizes, I can definitely say they're not the same. The tubes installed may come from the same source but they did this with the larger models too. The FV models have a few different features despite the chassis being numbered the same, better built in speakers, and much better quality control (although as with all fully flat WEGA's you need to open them up to tweak anyway).

A 24FV310? You sure it wasn't a 27FV310? I didn't know they ever manufactured 24 inch versions of it.

My experience with those was that post calibrated they're near identical except for the 310 having the benefits of the high voltage regulator. Granted the FV300's I picked up were new in box from an oldstock dealer some 7 years ago or so so there was no color fading or worn down contrast at all. Never saw a barely used 310 but that's a great find.

Yep it's a 24FV310, saw the model number on the back label myself.

And indeed it's got a different chassis part number than the 27FV310-to-36FV310.


I gotta say, I've very rarely seen the 24FV310. This was the first time I saw one with my own eyes, and I've seen one or two others max on local classifieds/FB marketplace/what have you.

Assuming this is correct that's amazing. Big revelation. I've never seen one even in pictures.

[Taiyaki]

The BA-5 and BA-5D chassis have separate jungle chips while the BA-6 has a combined micon and jungle chip. IIRC the image quality was slightly lower on the BA-6 chassis. Also the BA-6 Chassis don't fully disable VM even at 0, IIRC. So you must manually 0 out VM in the service menu or disconnect the neckboard. BA-5D has better gamma curve than BA-5.

I've had a somewhat opposite experience as the BA-6 has generally given me a slightly more favorable picture than the BA-5. The BA6 does have one weakness, which is in dealing with anything even slightly off the NTSC standard of 59.94hz. This means systems such as the Neo Geo (59.25hz) tend to show visual anomalies. The more off it is the more apparent the issues become. I think the BA-5 develops issues when going off the standard too but has more leeway. On the Neo Geo this is resolved by using a chip to force it to run at 59.94hz, which is within a margin of error that no one should notice, but for some MAME games this is an issue against the BA-6. For everything else the picture is actually cleaner and better to my eyes on the BA-6 chassis than the BA-5.

I forget if it's the BA-5 or BA-5D but one of them has slight red push that is never fully correctable in my experience (you either end up below or above the desired levels). Also regarding the BA-6 there's no VM at all when turned off (although that may have been via service menu as I disable it there anyway). That's never been an issue with the WEGA's as far as I know (unlike later Toshiba models).

[matt]

Having had many FS100's and FS120's of 20/24 inch models as well as FV300's of the same sizes, I can definitely say they're not the same. The tubes installed may come from the same source but they did this with the larger models too. The FV models have a few different features despite the chassis being numbered the same, better built in speakers, and much better quality control (although as with all fully flat WEGA's you need to open them up to tweak anyway).

That hasn't been my experience - the chassis and tube on the FS100 and FV300 are identical, as is the picture quality. The differences are in case design, speakers, and the inclusion of S-Video inputs on the 20FV300. Either way, I'd guess that I see at least 10 FS100s for every FV300 (of all sizes) locally, so it seems like the extra features weren't a big selling point at the time.

One downside of the FV300s these days is that (for the 24" model at least), the speakers suffer from foam rot and are usually blown out. The FS100 and FS120s seem to have fared better in this regard. I do live in a hot climate so it's probably not as big a problem in other parts of the world.

I forget if it's the BA-5 or BA-5D but one of them has slight red push that is never fully correctable in my experience (you either end up below or above the desired levels). Also regarding the BA-6 there's no VM at all when turned off (although that may have been via service menu as I disable it there anyway). That's never been an issue with the WEGA's as far as I know (unlike later Toshiba models).

VM can be disabled in the user menu on the FS100/FV300 models, but you do have to go into the service menu to completely turn it off on the FS120.

It's a bigger issue on curved Trinitrons - some of them have VM that can't be disabled except by disconnecting it. A few of the larger models have the VM board attached directly to the neck of the tube, and for these you have to either pull a component or physically cut one of the wires.

[Taiyaki]

I didn't know that older Trinitrons had forced VM. When I got back into CRT's I didn't bother all that much with the horizontally curved ones (aside from PVM/BVM monitors) since I have had a preference for flat flat ever since having them in the early 00's.

I think the main reason the mid size range of Trinitrons are so rare in the FV line is because people who went mid size were often more price conscious to begin with versus those who wanted to go big. I forget what the price difference was (had found the listings online some years ago) but it wasn't insignificant.

Oh and one other quirk of the BA-6 chassis is that they shipped out of the box with sub-normal contrast levels (brightness in the menus). Although I first discovered this when calibrating it myself, I found reading old reviews for these TV's that it was already documented back in the day. Users had to go into the service menu to push up the sub brightness settings as the regular menu max brightness setting was still clipping blacks. Pretty amazing a slip up really. All the different chassis have quirks that require tweaks to correct, but I found this one quite amusing.

[andykara2003]

A while back on this forum (10 years or so), 20/21” was often considered the best size for 240p on a consumer set. I think that was because the scanlines almost disappear in lieu of an even phosphor grid & hence the graphical elements are condensed enough to form a contiguous image, just like many of us were looking at back in the day when these games were current.

Now people want heavy, thick scanlines with as little scanline bleed as possible. Nothing wrong with that, or any image style, it’s just ironic that no one gave a shit about scanlines back then - in fact I remember hating excessive scanline prominence. I once went to a 27” (29” in the UK) & regretted it.

[FinalBaton]

24/25 inches crt is my preferred size these days, hands down. (outside of desktop gaming setups where 13/14 inch are my fave).



Regarding my friends tv : I guess it was a 24FV300 altough I remembered 24FV310.

[Taiyaki]

A while back on this forum (10 years or so), 20/21” was often considered the best size for 240p on a consumer set. I think that was because the scanlines almost disappear in lieu of an even phosphor grid & hence the graphical elements are condensed enough to form a contiguous image, just like many of us were looking at back in the day when these games were current.

Now people want heavy, thick scanlines with as little scanline bleed as possible. Nothing wrong with that, or any image style, it’s just ironic that no one gave a shit about scanlines back then - in fact I remember hating excessive scanline prominence. I once went to a 27” (29” in the UK) & regretted it.

Actually I feel the peak of wanting thick scanlines was about 5 years ago. Slowly little by little I've seen more and more people want thinner or near invisible scanlines, in favor of more noticeable phosphor grids.

My favorite size is 20/21 inch CRT TV's, but 24/25 inch is outstanding, and arguably optimal for multiplayer too.

[andykara2003]

Yes 25” is great too, mine packed up so I might have to pick another up.