Neotec NT-2701 / ArcadeVGA / J-Pac question for all you brainy-expert-hero-types

[DavidBowman]

Hey all!

Recently I decided that I wanted to build a MAME cabinet.

Now, although I'm not new to computers, I am new to arcade machines, so I must apologize in advance for my ignorance. I tried to find these answers on my own through searching, I really did! I really just want some clarification!

I managed to find a Gauntlet Legends cabinet without the PCB but with a working monitor and control panel locally. Before I had the cabinet in my possession, I ordered an ArcadeVGA (AGP) card and a J-Pac from Andy at Ultimarc.

Unfortunately, after I got the cab, I noticed that I had a few hurdles to overcome. I stupidly didn't do enough research before I ordered from Ultimarc.

The first hurdle is that the monitor is a 25 kHz monitor. 
It's a Neotec NT-2701 to be more exact. (I've read that some of these can be set to 15 kHz with a jumper, anyone know about this one?)

I've seen SailorSat's Soft-15KHz program, I've seen Powerstrip and I've got both the AVGA and an nVidia 6200 (both AGP) that I can use.

Is it possible to output the video with the hardware I have? Do I need to get additional hardware? The AVGA card won't output to a 25 kHz monitor right? Just the Tri-Sync ones?

Much of what I've learned about this project of mine comes from another Gauntlet Legends conversion that I read about here: http://www.dragonslairfans.com/smfor/index.php?topic=6.0

In the above link, he used a Universal Video Converter from Happs. Will this be my best bet or is there anything similar that isn't so pricey?

Thank you so much in advance for having patience with this n00b. 

[Ken Layton]

The Neo Tec 2701 is one resolution only and it's a medium res monitor (EGA).

[DavidBowman]

Thank you for your reply, Ken. That was probably the most difficult question to find an answer to since I can't locate a manual or schematics for this monitor online.

Do you know about the AVGA card and getting it to output the correct frequency? I've looked into AdvanceMAME just a bit and it seems to support this ATI chipset (the Radeon 9250). Also, would the Soft15 or Powerstrip programs allow this in Windows? I know that the AVGA does allow 25 kHz frequencies, but only if you enable it with the Tri-sync utility and as you know, I don't have a tri-sync monitor.

I know that I could just start experimenting, but I'm afraid that I'm going to blow something up (not really, but that would be my luck).

Thank you again!

[Ken Layton]

You won't find much for Neo Tec monitors online as Neo Tec enforces their copyrights. Neo Tec sells manuals from their parts department.

www.neotecgraphic.com

[DavidBowman]

Well, what I meant was that I didn't see that Netotec had any freely-downloadable guides for download. Plenty of companies make their manuals available in PDF format for their products.

Remember that bit about my luck? I don't know what's happened now, but I think I really did screw up the monitor.

I had this monitor connected to the J-PAC, and the 25khz jumper set on the J-PAC as well. When I powered on my PC, the J-PAC's Sync In light would come on, but not that Sync OK light.

For some reason, I saw a scrambled picture anyway.

After trying Soft-15khz with the ArcadeVGA (which seemed easy enough), I set it to 512 x 384 16-bit.

Well, now the monitor beeps at me and I get no picture. When it first started beeping, I flipped off the power supply and pulled the power cord out of the wall. I think I also smelled that solder smell.

I blew it up, didn't I?

[Zebidee]

How about you get another video card that is known to work well with Soft15Khz (eg ATI Radeon 9200, about $50-80), then run that software and install 25khz modes?

Gotta be worth a shot.

If your monitor chassis is slagged, but the tube is OK, you could try getting a generic chassis to run on it from www.jomac.net.au

[DavidBowman]

Yes, that would be worth a try.

The monitor is dead for now though. It's chirping/beeping at me when I put power to it. The second to the last post here sums it up: http://newlifegames.net/techforum/index.php?PHPSESSID=abcc465bfa97e45e16ad52aeb61d0f20&topic=1085.msg6144

I'm not sure what I'm going to do at this point. I've built computers, but I'm not confident enough to start messing with arcade monitor electronics. I'd kill myself for sure.

[Zebidee]

I'm not confident enough to start messing with arcade monitor electronics. I'd kill myself for sure.

Well, we wouldn't want anybody to do that.  In that case, you might be better off contacting a local arcade/monitor tech.

It sounds like you need a new monitor chassis, because your old one is only good for 25khz anyway.  Contact Jomac, they can help you with this.

If you are able to safely discharge a monitor (read the stickied monitor FAQ) and remove the chassis (PCB, electronics board + neckboard), you can easily replace it with another.  If this seems a little scary too, then perhaps there is a competent friend or forum member near you.  If you are inexperienced with discharging monitors, then having a second (responsible) person around is a good safety precaution and a damn good idea.

[grantspain]

neotec nt2701 are known for failure on the horizontal deflection transistor and the polyporpylene high voltage capacitor on said transistors collector pin

[DavidBowman]

Thank you so much for the advice, guys! 

I actually have contacted a local arcade tech that I know about this problem.

Am I to understand that I could replace the chassis with another that would allow for more than just 25 khz resolutions then? That would be the best solution I think.

[Zebidee]

Am I to understand that I could replace the chassis with another that would allow for more than just 25 khz resolutions then?

YES! 

Start by looking here:  http://www.jomac.net.au/parts.htm

Look for the SHARP Image dual res (15-25k) chassis about 1/2 way down the page.

[DavidBowman]

Thank you again.

Unfortunately, I'm located in the US. I may still try Jomac, but if I have to spend that much on to repair this monitor, I'd probably rather invest in a Tri-Res monitor.

I see that the Betson 27" multi-sync is a good price right now ($375 USD): http://www.betson.com/products/IMP-44-4070-RT

I'm also interested in a Billabs unit: http://www.billabs.com/bl27cb0p.htm

Any suggestions on that? Betson, Neotec, Hantarex, Makvision? I keep reading various satisfaction reports on all of them. Wells Gardner is not an option thanks to Ken's review among many many others that I've read. I appreciate the warnings, Ken.



And one more question about the J-PAC just out of curiosity. I thought that when the 25 khz jumper was set, unless I got a Sync OK light, I shouldn't have seen any picture on my monitor. I thought that having a J-PAC added a safety buffer to your video signal. Am I confused about that?

You guys are awesome, thanks so much!

[Zebidee]

Setting the 25khz jumper on the jpac tells the jpac to pass 25khz signals only.

If you set the jumper to 15khz, it will only pass only 15khz signals.

If you set two jumpers, on 15khz & 31khz, it will pass 15khz and 31khz, but will splt the 31khz so that you get two long screens (that probably look pretty bad/rough).

The SYNC OK light comes on when the jpac detects an acceptable video signal (refer the jumpers).

[DavidBowman]

So, in other words, acceptable signals or not, there will be display?

I think I really will go with that Betson since it's on sale for the Winter (well, it's Winter where I am). Anyone have any particularly negative things that they know about the 27" Betson Imperial?

Thanks, Zebidee.

[grantspain]

are you gonna get a avga card/use soft 15k or just use 31k?

[DavidBowman]

I already have an AVGA card as well as a J-PAC, but I might try to see if that nVidia 6200 I have would also work with Soft15.