V. Linearity help for PVM 1454QM

[keropi]

Hiya!
Anyone here knows what's the secret to fix VERTICAL LINEARITY on my PVM1454QM set? I've been messing with settings but I could not get it to look better...
See the following photo, the squares at the top area are taller that those at the bottom - and V.LINEAR is at 0






One would think that setting the value at 0 is not really good but here is what happens the more I raise it:



the upper squares gain more height

This test pattern is from 240p Test Suite running on a JP Megadrive 1.
What am I missing here? Is there something else that affects that and I need to adjust it? I have tried inputting the default values from the service manual but they kinda kill the geometry - so much that I think there is a typo in a couple of values on the service manual...

Any ideas how to proceed? It's not supposed to look like that right?
Thanks!

[xAzurexEonx]

Welcome to the world of pain for perfect picture.

I'll assume you already know how to access and use the service menu.

You'll just have to keep playing with those settings. Pin amp variables might help here.

Maybe someone will tell you their exact settings for this model.

[keropi]

heheheheh well I am not *that* picky but vertical scrolling games do show a distortion.
Indeed I have accessed the service menu and tried various combos but the exact ones elude me. Maybe there is a pot on the chassis?

At any rate, I have purchased the Service Manual as well since I could not find a free download, it is valid for the 1450QM and 1454QM models , you can grab it here: http://www.mediafire.com/file/dab6oxm8y ... M_SONY.rar

[xAzurexEonx]

Thanks for sharing.

Looking at it, it does look like it is the very same menu as my 20M4U.

Page 22

The ones listed with the NOR settings.

The only POT I know of that affects the screen is one in the upper right (if looking from the back of the monitor), but believe this only influences how far right/left.

[keropi]

here is what the default values on the service manual look like:



quite horrible that's why I think they are wrongly listed.

I will do a settings reset, there is no telling what the previous owner(s) did.

edit:

I don't understand how to perform a complete factory reset... can someone break it down to me? I can go into service menu and change/store settings but how to do a global reset?! page21 instructions are not clear to me

[xAzurexEonx]

Supposedly : Open Menu, press Enter+Degauss, hold Blue only/Reset until it says factory, press Blue only/Reset again.

The service manual has the base setting fro which the factory would start from or if tech had to redo it all. Like now you now have the entire screen filled. It is a very big pain.

[Rossyra]

I would not do a factory reset. As the components age, the settings drift. As already said, it's a matter of tweaking not bludgeoning.

[DoomsDave]

Highly recommend NOT doing a factory reset as well. Not all monitors are the same and most were calibrated by a technician. Doing a factory reset will most definitely cause more problems then it will fix.

You're just going to have to spend the time going through the settings and documenting your changes until you find a solution. It's a pain in the ass but it's just something you have to go through.

[AndehX]

I have a similar issue with my 20G1E, It has horizontal linearity issues on the left side of the screen. You can clearly see horizontal scrolling games (every 2d platformer ever?) visually warping on the left side. It's horrible and I've tried every setting in the service menu to fix it, but I think its simply down to wear and tear on the components over time. Next to a recap... there's pretty much nothing I can do about it

[keropi]

Thanks again for all your replies, appreciate them.
I went ahead and did a factory reset. I know some of you don't approve but consider this: I have no idea how many previous owners the monitor had or what they did to it so there is no real guarantee the settings are good .
After the reset ofcourse I had terrible geometry but after fiddling 5mins on the service menu I ended up having the same result as the one I posted above, so nothing was really lost. Colors are good like before, geometry the same and V.LINEARITY at 0 is still the best option.

I have no idea how to proceed now, it seems to me the issue is not on the settings. Maybe a recap?

[AndehX]

It could help, but i'm not exactly sure what issues a recap will improve/fix. I think geometry issues can definitely be rectified by installing new capacitors, but linearity? Maybe someone else can chime in on that one...

[AndehX]

Heres an example of the linearity on my monitor. It might be hard to see (hard to capture on camera) but if you look at the area I've marked in red, you should be able to see the image compressing slightly, before returning to normal at the edge of the screen

https://www.dropbox.com/s/ipw8tci17qfjt ... 4.mp4?dl=0

[keropi]

oh my that's annoying!

[keropi]

It seems these linearity issues are caused by caps going out of specs so a recap is needed. Caps near hot places just drift over time and affect geometry. I will recap the chassis (at least the large caps near hot transistors and heatsinks) and report back, I found a post on facebook with someone having the same issue as mine (his was way worse though) and a recap did the trick.
AndehX you should recap as well IMHO

[AndehX]

I will definitely recap at some point, but getting caps will be a pain as I'll have to pull the boards out and note all the capacitors and their locations. I'll definitely do it at some point. What caps would be best? Nichicons? Definitely update with your results!

[DejahThoris]

I will definitely recap at some point, but getting caps will be a pain as I'll have to pull the boards out and note all the capacitors and their locations. I'll definitely do it at some point. What caps would be best? Nichicons? Definitely update with your results!

Nichicons 105 degree are an excellent choice. It's a long process, but worth the trouble. Be sure and write down the values and locations and post them here as well for the next guy. People would be able to easily order cap kits for their model if more people shared their work!

[AndehX]

I have a 9" BVM being delivered tomorrow, which which will give me the opportunity to recap my 20" Once I record down the caps and their locations, I'll post them here.

[keropi]

I don't plan to do a full recap atm, there are just TOO MANY on the board. I'll start with the bigger value ones - that tend to be more sensitive to time/heat. The 1454QM must have close to 180-200 caps
I will update with my results once that is done.

[AndehX]

Well, I'll only be replacing the caps on the input and deflection boards. Those seem to be the source of most of the issues that plague these monitors. The deflection board has somewhere around 30- 40 caps on it

[keropi]

Mine has 3 boards with caps: main , psu and the neckboard that has 2-3 electrolytics. I'll only do the 220~1000uf ones and the 7-8 that are few uf but high voltage. It must be 20-25caps in total.
I also noticed that the main/neckboard use good japanese caps and the PSU is full of LeLon ones... sony went cheap again

[xAzurexEonx]

Service manuals have parts list, which include location. No need to map out. This also helps if you ever encounter the odd Sony exclusive resistor (etc) and need the exact name to find a newer replacement.

[buttersoft]

Service manuals have parts list, which include location. No need to map out. This also helps if you ever encounter the odd Sony exclusive resistor (etc) and need the exact name to find a newer replacement.

Actualy most newer Sony SM's include cross references for all parts *except* caps, believe it or not. And possibly resistors. Older SM's don't have any references beyond the fact the lists are broken up by board.

Thanks to Keropi for sharing that SM, i have a busted one of those sets sitting on the bench right now

[keropi]

^ glad the SM can help , do post what the issue turned out to be

[xAzurexEonx]

Service manuals have parts list, which include location. No need to map out. This also helps if you ever encounter the odd Sony exclusive resistor (etc) and need the exact name to find a newer replacement.

Actualy most newer Sony SM's include cross references for all parts *except* caps, believe it or not. And possibly resistors. Older SM's don't have any references beyond the fact the lists are broken up by board.

Thanks to Keropi for sharing that SM, i have a busted one of those sets sitting on the bench right now

What I was saying that the SM actually gives you the value/type. So you can do the cross-referencing for those yourself if you had to. Caps dont need them since you only need to match a value 99% of the time.

The 20M4U has a pair of resistors that handle fast switching. They were Sony design and now hard to find cheaply, but the manual at least had its official name. So it helped narrow down a suitable replacement.

[AndehX]

Quick question. Is it wise to replace the SMD capacitors as well as the through holes?

[xAzurexEonx]

Quick question. Is it wise to replace the SMD capacitors as well as the through holes?

There isn't any issue but smd can be a pain if you don't have hot air imo.

From MY experience the SMD caps will be VERY visibly damaged if they are no good, pretty sure this is how they are intended to be, think fuse?. Through hole is harder to tell sometimes that they are damaged/weakening/leaking and cause of an issue.

[AndehX]

Ok well, it's easy enough to remove the boards from the monitor, so I'll just do the through holes for now and see if it makes a difference.

[AndehX]

removed the input, deflection and power supply boards today. Made a parts list of all the electrolytes. 99 capacitors all together. Now I need to find somewhere to buy replacements in the UK.