NEC XM/XP 29/37 Pro/Xtra Thread

The place for all discussion on gaming hardware
chibishin
Posts: 13
Joined: Wed Mar 23, 2016 2:30 pm
Location: USA

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by chibishin »

kel wrote:My 3778G is partially disassembled awaiting a recap so I should be able to easily check for you although due to the fact that they are slightly different models I can't guarantee either way that what I find in mine should be the same in yours.

EDIT: Just had a quick look and none of the boards or connectors seem to match the numbers on yours. Could you take a photo of the board that you are referring to and maybe a close up of the section with the missing part so that I can see if it is anything like the one in mine?
Sure, here's a hi-res photo.
kel
Posts: 227
Joined: Wed Dec 22, 2010 11:11 pm

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by kel »

Sorry but it doesn't seem like I'm going to be much help with this one. My 3778G doesn't have a board that looks anything like that one in it, must have been something they added when they designed your particular model.
xga
Posts: 205
Joined: Thu Jun 04, 2015 12:59 am

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by xga »

chibishin wrote:I'm in the process of replacing the electrolytic caps on an XP37 (XP-3790) I recently picked up, and I've possibly run into a slight issue.

While working on the Chopper Reg PCB (PG319B), I noticed that the transistor in location Q1 is missing but there are definitely still leads in the through-holes. It looks like the legs were snipped because they're all pretty level and straight upright, and I know I didn't do it.

Before I go down the path of possibly replacing a part that was removed at the factory, I was hoping another XP37 owner could check theirs for me and see if they have a transistor at Q1--it's adjacent to CNB01 which connects to CN406 on the Horizontal Deflection PCB. If there's one there, could you get the value for it? I'm assuming it's a 1202 like the others on that circuit, but just in case it's not.

Or if anyone has a schematic handy, that'd be helpful, too.
So the service manual states that Q1 is a 1202 like you said:

Image

However, looking at the circuit diagram it says that Q1 (and Q20 also) are NC (no connection?) so I presume that there was never a Q1 from the factory. I can see in the photo that you took that Q20 is also vacant, matching the NC marking in the circuit diagram.

Image
chibishin
Posts: 13
Joined: Wed Mar 23, 2016 2:30 pm
Location: USA

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by chibishin »

xga wrote:
chibishin wrote:I'm in the process of replacing the electrolytic caps on an XP37 (XP-3790) I recently picked up, and I've possibly run into a slight issue.

While working on the Chopper Reg PCB (PG319B), I noticed that the transistor in location Q1 is missing but there are definitely still leads in the through-holes. It looks like the legs were snipped because they're all pretty level and straight upright, and I know I didn't do it.

Before I go down the path of possibly replacing a part that was removed at the factory, I was hoping another XP37 owner could check theirs for me and see if they have a transistor at Q1--it's adjacent to CNB01 which connects to CN406 on the Horizontal Deflection PCB. If there's one there, could you get the value for it? I'm assuming it's a 1202 like the others on that circuit, but just in case it's not.

Or if anyone has a schematic handy, that'd be helpful, too.
So the service manual states that Q1 is a 1202 like you said:

<snip>

However, looking at the circuit diagram it says that Q1 (and Q20 also) are NC (no connection?) so I presume that there was never a Q1 from the factory. I can see in the photo that you took that Q20 is also vacant, matching the NC marking in the circuit diagram.

<snip>
Yesssss, you are a lifesaver. Thanks a bunch for the help! Any chance the manual/schematic are scanned somewhere? I've dug through google quite a bit but could only find the user manual.

If not, any chance you could be persuaded to scan it? I'd be willing to make it worth your while.
Nodoyuna
Posts: 117
Joined: Tue Jul 24, 2012 10:09 am

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by Nodoyuna »

Quick question: are the case of the XM29 and XM37 made from plastic or are more like PVM's (I think they're metal cases)

I'm having issues at home with interferences, but it seems to only affect one of my monitors (Hantarex with plastic case), but the other one seems not affected (PVM 2730QM)

As I'm planning to get both monitors in the future, I'd like to know if the cases are prone to getting interferences or not

Thanks in advance
chibishin
Posts: 13
Joined: Wed Mar 23, 2016 2:30 pm
Location: USA

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by chibishin »

Nodoyuna wrote:Quick question: are the case of the XM29 and XM37 made from plastic or are more like PVM's (I think they're metal cases)

I'm having issues at home with interferences, but it seems to only affect one of my monitors (Hantarex with plastic case), but the other one seems not affected (PVM 2730QM)

As I'm planning to get both monitors in the future, I'd like to know if the cases are prone to getting interferences or not

Thanks in advance
viewtopic.php?p=1330946#p1330946

The XM/XP37 have what I'm assuming is an ABS back, but this is what is underneath. I'd say it's pretty well shielded with the exception of the PCB handling video input.
kel
Posts: 227
Joined: Wed Dec 22, 2010 11:11 pm

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by kel »

chibishin wrote:
xga wrote:
chibishin wrote:I'm in the process of replacing the electrolytic caps on an XP37 (XP-3790) I recently picked up, and I've possibly run into a slight issue.

While working on the Chopper Reg PCB (PG319B), I noticed that the transistor in location Q1 is missing but there are definitely still leads in the through-holes. It looks like the legs were snipped because they're all pretty level and straight upright, and I know I didn't do it.

Before I go down the path of possibly replacing a part that was removed at the factory, I was hoping another XP37 owner could check theirs for me and see if they have a transistor at Q1--it's adjacent to CNB01 which connects to CN406 on the Horizontal Deflection PCB. If there's one there, could you get the value for it? I'm assuming it's a 1202 like the others on that circuit, but just in case it's not.

Or if anyone has a schematic handy, that'd be helpful, too.
So the service manual states that Q1 is a 1202 like you said:

<snip>

However, looking at the circuit diagram it says that Q1 (and Q20 also) are NC (no connection?) so I presume that there was never a Q1 from the factory. I can see in the photo that you took that Q20 is also vacant, matching the NC marking in the circuit diagram.

<snip>
Yesssss, you are a lifesaver. Thanks a bunch for the help! Any chance the manual/schematic are scanned somewhere? I've dug through google quite a bit but could only find the user manual.

If not, any chance you could be persuaded to scan it? I'd be willing to make it worth your while.
I would also be interested in a copy if you do ever make a scan of it. Although it might be different from the 3778G I'm sure that there would be some similarities shared between them. Unless by any chance you have a service manual for the 3778G lying around also, I'd definitely be willing to make it worth your while too if so.
shmupsman
Posts: 11
Joined: Fri Jul 29, 2016 10:58 am

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by shmupsman »

kel wrote:I would also be interested in a copy
+1 :) PLEASE
Twin-X
Posts: 11
Joined: Tue Jul 22, 2008 12:15 pm

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by Twin-X »

Hi,

Does anyone have servicemanual copy for the pg-2940G (4PG)

It stopped working and i suspect a burned transistor to lopt or somekind. Black screen however tube is nice glowing and leds on front + sound work.

Thanks
Sefirosu789
Posts: 83
Joined: Sun Jul 30, 2017 5:05 pm
Location: UK

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by Sefirosu789 »

Hi all. Can someone please upload the service manual for the NEC XP29 Plus? The link in the first post doesn't appear to work anymore and I can't find it anywhere online.

I managed to pick up two of these but like most NEC's I've seen online, both have some kind of small geometry issue in one or two corners. I would really like to take a look at the service manual!
User avatar
aaronmjr
Posts: 103
Joined: Mon Dec 08, 2014 5:06 pm
Location: MN

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by aaronmjr »

Wondering if anyone has a service manual for....

Just kidding. 8)
User avatar
andykara2003
Posts: 1338
Joined: Sat Apr 27, 2013 3:26 pm

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by andykara2003 »

Out of interest, does the XM29 produce scan lines when displaying 480p content?
User avatar
Hoagtech
Posts: 939
Joined: Mon Apr 27, 2015 3:53 am
Location: Bellingham, WA

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by Hoagtech »

andykara2003 wrote:Out of interest, does the XM29 produce scan lines when displaying 480p content?
I don’t own that model but I own the mitsu..

It displays 240p over 480p quite well with scanlines density options. *with OSSC and DAC

I would guess the same

*edit 3/20/19 added OSSC to message
Copyright 1987
User avatar
andykara2003
Posts: 1338
Joined: Sat Apr 27, 2013 3:26 pm

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by andykara2003 »

Cheers - although I mean scanlines when running a 480p on a console like the GameCube. Some CRTs do display small scanlines on 480p material.
Dochartaigh
Posts: 1519
Joined: Thu Mar 02, 2017 6:53 pm

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by Dochartaigh »

I asked this question elsewhere and never got an answer...hopefully you pros know: can these NEC monitors do 16:9 widescreen? (and I'm not talking about squeezing the image via the service menu so it's 16:9-esque, like a proper 720p widescreen mode via a button press or whatnot).
User avatar
aaronmjr
Posts: 103
Joined: Mon Dec 08, 2014 5:06 pm
Location: MN

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by aaronmjr »

andykara2003 wrote:Out of interest, does the XM29 produce scan lines when displaying 480p content?
I don't believe so for 480p content. For 480i content though, there are noticeable blank spaces between pairs of lines. This seems to be common with multisync monitors. My friend's Sony PVM 20L5 does the same thing.

Dochartaigh wrote:I asked this question elsewhere and never got an answer...hopefully you pros know: can these NEC monitors do 16:9 widescreen? (and I'm not talking about squeezing the image via the service menu so it's 16:9-esque, like a proper 720p widescreen mode via a button press or whatnot).
There's no dedicated button to change aspect ratios. There's a "Scan Select" button that may accommodate 16x9 resolutions better, but I'd have to test to see.
Last edited by aaronmjr on Thu Mar 21, 2019 7:18 pm, edited 1 time in total.
haightc
Posts: 12
Joined: Thu Oct 06, 2016 6:46 pm

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by haightc »

So how do I get my XM2950 do default to overscan mode, everytime a resolutions switch I have to press the scan button to fill the screen again?
User avatar
aaronmjr
Posts: 103
Joined: Mon Dec 08, 2014 5:06 pm
Location: MN

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by aaronmjr »

haightc wrote:So how do I get my XM2950 do default to overscan mode, everytime a resolutions switch I have to press the scan button to fill the screen again?
I keep trying to remember to test this at home. I'm going to try changing the scan mode while on an input, then press "User preset" and see if it sticks next time I power the monitor on.
User avatar
ChuChu Flamingo
Posts: 293
Joined: Sun Feb 19, 2012 9:32 am
Location: United States

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by ChuChu Flamingo »

Just acquired a nec xm 29 and having a few problems.

To begin here is my full setup.

Gscart Lite
BNC to scart female with no sync stripper
Sega Saturn Csync Cable with 470ohm resistor
PS2 Scart cable sync on luma with 1000uf caps
PS1 Scart cable sync on luma with 220uf caps


Hokuto No Ken

https://youtu.be/gsiC6aJ8JvE

Notice how the screen size changes. On my Nec XM2950 I have the switch set to HIGH, not 75 ohm. If I set to 75 ohm it doesn't do this but my contrast sucks ass. Turning down the contrast on high makes it not happen but then my contrast sucks.

https://youtu.be/BaRmw1eApXg

screen takes a split second to switch from 480i to 240p etc. I tested n64 majoras mask with 240p/480i switching via menu and bombers notebook and no such drop. Pokemon stadium is the same.


Is there a setting/dip switch I am missing here? Do I need a sync stripper for my rgb even though the gscart already provides clean cysnc?

I don't mind opening it up to adjust pots since S-video could use more contrast. I could also adjust the width pot but I can't find the PG2770 service manual that details all this. All I have to go by is Spiderwaffles postings...

Thanks
User avatar
ryu
Posts: 1876
Joined: Mon May 31, 2010 6:43 pm
Contact:

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by ryu »

I have never come across a fix for that problem. The screen distorts in accordance to the voltage required to display it (so depending on the brightness). Think you got to live with that. If there's a fix I'd be interested to know too.
blog - scores - collection
Don't worry about it. You can travel from the Milky Way to Andromeda and back 1500 times before the sun explodes.
User avatar
FinalBaton
Posts: 4461
Joined: Sun Mar 08, 2015 10:38 pm
Location: Québec City

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by FinalBaton »

You should not be putting the impedance to high (unless you have a source collected to the throughput).

If your contrast completely sucks, maybe there's something wrong with the monitor.
I remember that with mine, I had to spend a ton of time tweaking brightness and contrast to find the best balance between the two. but once I did it looked great.
-FM Synth & Black Metal-
User avatar
Shogun
Posts: 98
Joined: Sat Jan 15, 2011 9:17 am

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by Shogun »

Rochabian wrote:Hi dear owners of those greatfull monitors
I've got an XM29 + in an arcade cab since 5 years and recently I hear a very high whistle when I play in 15khz. It does not occur on resolutions higher than 640x480. I was told that it could come from coils that would vibrate at 15khz and would be audible. I tried to touch the components with a stick to see if the noise stopped but since I do not know where these reels are, it's a bit difficult. Can someone tell me where I should look? It seems to me that the sound comes from the PCB on the right when we look at the monitor from behind. I was also told about the very high voltage module that can vibrate. What do you think ?
Its the flyback transformer. You can see my details of this problem and what I tried at: https://assemblergames.com/threads/nec- ... ise.48930/

I have had this problem for many years. Because of this my XM29 Plus has sat in the closet for a long time. I haven't looked for a while but I have yet to see anyone perform this repair. Because this is one of the most dangerous components in the monitor I wouldn't want to attempt this without some clear instructions. The thing is too much of a hassle with the fans and screeching noises.
DejahThoris
Posts: 719
Joined: Sat Oct 19, 2013 10:26 pm
Location: Riverside, CA

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by DejahThoris »

Tightening the screws that hold on the flyback helped one of the two of mine.

If anyone knows the part number for the flyback it'd probably do a few of us some good.
Cannonballs
Posts: 124
Joined: Tue Oct 30, 2018 8:29 pm

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by Cannonballs »

What is the best way to connect ypbpr component to the xtra/plus line?
User avatar
FinalBaton
Posts: 4461
Joined: Sun Mar 08, 2015 10:38 pm
Location: Québec City

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by FinalBaton »

Cannonballs wrote:What is the best way to connect ypbpr component to the xtra/plus line?
I used a Mayflash transcoder to connect a psp to mine : http://www.mayflash.com/Products/VIDEOA ... GA005.html
It certainly looked good but I haven't done any captures to analyze it's performance so I couldn't tell you whether it crushes black or not.

Also am not 100% sure if it accepts 480i/240p. I think it did. But the description in the link above doesn't mention it.
It's powered by USB, which may be handy depending of your setup.
It can also be had for as low as $13.

Not saying it is the "best" but, hey... just throwing my experience out there.
Now I'm sure someone will jump in to say it's trash, haha!

EDIT : looks like it looses sync for a half-second when a picture goes from full white to full black, but this can be repaired if you open the unit : https://www.reddit.com/r/crtgaming/comm ... erter_any/



Maybe you'd be best with an Extron CVC 200 or 300, as suggested in there. Extron gear is pretty much always reference level

Also, the OSSC does this I think, but you'd need an HDMI to VGA transcoder chained to the output
Last edited by FinalBaton on Thu Aug 08, 2019 3:04 am, edited 2 times in total.
-FM Synth & Black Metal-
xga
Posts: 205
Joined: Thu Jun 04, 2015 12:59 am

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by xga »

Cannonballs wrote:What is the best way to connect ypbpr component to the xtra/plus line?
Do you have a Xtra model? Both the XM-2961 and the XP-2991 Xtra models support component natively and don't require the use of a transcoder.
Cannonballs
Posts: 124
Joined: Tue Oct 30, 2018 8:29 pm

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by Cannonballs »

xga wrote:
Cannonballs wrote:What is the best way to connect ypbpr component to the xtra/plus line?
Do you have a Xtra model? Both the XM-2961 and the XP-2991 Xtra models support component natively and don't require the use of a transcoder.
It’s an xtra and it’s 37, xm3761 is the model number. Will YPbPR work through the RGB BNC input? Or do I need a YPbPR to VGA converter to put component in through the VGA input? I’ve never had a multi sync monitor or anything that does above 480i, sorry if this all sounds stupid.
User avatar
aaronmjr
Posts: 103
Joined: Mon Dec 08, 2014 5:06 pm
Location: MN

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by aaronmjr »

Cannonballs wrote:
xga wrote:
Cannonballs wrote:What is the best way to connect ypbpr component to the xtra/plus line?
Do you have a Xtra model? Both the XM-2961 and the XP-2991 Xtra models support component natively and don't require the use of a transcoder.
It’s an xtra and it’s 37, xm3761 is the model number. Will YPbPR work through the RGB BNC input? Or do I need a YPbPR to VGA converter to put component in through the VGA input? I’ve never had a multi sync monitor or anything that does above 480i, sorry if this all sounds stupid.
Both the VGA and BNC ports accept the exact same signals. Grab some BNC>RCA adapters and give it a try. :D

EDIT: Sounds like I was wrong.
Last edited by aaronmjr on Thu Aug 08, 2019 2:46 pm, edited 1 time in total.
xga
Posts: 205
Joined: Thu Jun 04, 2015 12:59 am

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by xga »

Cannonballs wrote:It’s an xtra and it’s 37, xm3761 is the model number. Will YPbPR work through the RGB BNC input? Or do I need a YPbPR to VGA converter to put component in through the VGA input? I’ve never had a multi sync monitor or anything that does above 480i, sorry if this all sounds stupid.
The XM-3761 supports RGB, YCbCr and YPbPR via the RGB 2 BNC connections only.

Image

If the colour of the image is incorrect, you will need to change the RGB 2 signal format from the DV controls option in the OSD menu. Best to set the signal format to AUTO if it isn't already.
Archangel2878
Posts: 2
Joined: Fri Aug 16, 2019 1:05 am

Re: NEC XM/XP 29/37 Pro/Xtra Thread

Post by Archangel2878 »

Idk if anyone has posted this already but I need the service manual for the Nec PG2710 any help would be appreciated thanks update :// got it !!
Last edited by Archangel2878 on Tue Aug 20, 2019 4:03 am, edited 1 time in total.
Post Reply