Sega Net City Restoration

[Adrick]

Next on the work list: audio amplifier. I replaced the electrolytic capacitors and the thermal paste on the heat sinks and transistors.

The original speakers were completely dead (maybe caused by the unloading mishap?) which is fine since I wasn't going to use them anyway. I read that people are replacing them with car speakers and that is what I did as well. The original speaker impedance isn't indicated on the speakers and when I tried to measure their resistance, I didn't get a reading (because they are broken). But the manual does list them as 4 ohm so car speakers are okay. I'm using Focal Auditor RCX-100 speakers. They fit perfectly.

The speaker location in this cabinet is just barely out of the danger zone for magnetic interference. If the speaker is moved forward so that the front of the speaker is directly below the screen, or tilted up or down, I can see discoloration on the screen. Even in the normal position I can see a very slight warping of the image on screen compared to when the speaker is not installed. Because of this I wrapped the magnets with four layers of sheet metal. Even four layers wasn't enough to fully shield them but it's enough to not see any change on screen when installed. If I were to place the monitor in vertical position it would be a few inches closer to the speakers. Even then the speakers wouldn't cause discoloration but I think I would add some sheet metal around the outside of the plastic enclosure to be certain. I plan on keeping this monitor in horizontal position because none of the JVS vertical shooters interest me (sorry, not an Ikaruga fan).

https://lessemf.com/shielding-faqs/


I took apart the CRT cover/speaker enclosure during cleaning so I added new silicone sealant inside.

I put the new speakers in today and the sound quality is very good and very loud. Better than expected. I don't need to upgrade the audio amplifier.


My florescent light wasn't working when I got this cabinet and the bulbs aren't easy to find in the USA. Since I was already ordering some things from Yahoo Japan Shopping, I bought some new bulbs and new starter bulbs. The bulbs were less than 200 yen each.

The bulbs in my three cabinets are each from different manufacturers and there are two different model numbers among them, FL20SD-B and FL20SS・D/18. Both models are nearly identical and both are compatible with any of the three cabinets. These are the specifications:

color temp: 6500K
diameter: FL20SD-B = 32.5mm, FL20SS・D/18 = 28mm
length: 580mm
power: FL20SD-B = 20w, FL20SS・D/18 = 18w
starter bulb: FG-1E
life: 8,500 hours
lumens: 1,070

What model of Toshiba fluorescent tube does the nnc come with as standard.

Looking at the instruction booklet I can't find it, my nnc comes with a Toshiba tube but it fits a bit tighter.

 

[Thomas]

What model of Toshiba fluorescent tube does the nnc come with as standard.

Looking at the instruction booklet I can't find it, my nnc comes with a Toshiba tube but it fits a bit tighter.

Based on the Old Net City manual I'd say FL20SD. The model should be printed on your tube.

 

[Adrick]

Based on the Old Net City manual I'd say FL20SD. The model should be printed on your tube.

How can I buy an fluorescent now through Yahoo shopping, apparently it is restricted to Japanese territory.

 

[djsheep]

Get fluro tubes from local hardware or lighting stores.

 

[Thomas]

How can I buy an fluorescent now through Yahoo shopping, apparently it is restricted to Japanese territory.

If you can't find a size that will fit locally, you can use a proxy service like buyee.jp. Shipping is expensive. I only bought from Yahoo Shoppping because I ordered other things and adding the tubes didn't affect the shipping cost much.

 

[Adrick]

If you can't find a size that will fit locally, you can use a proxy service like buyee.jp. Shipping is expensive. I only bought from Yahoo Shoppping because I ordered other things and adding the tubes didn't affect the shipping cost much.

Yes I am currently using buyee although I can't find the philips model I guess they are difficult.

Get fluro tubes from local hardware or lighting stores.

Yes, even if they have a difference in lumens or size, surely thanks you ☺

 

[Thomas]

There are plenty of tubes on shopping.yahoo.co.jp with model FL20SD or FL20SS. I wouldn't worry about the brand. After fees and shipping it won't be cheap. Definitely check your local stores and online stores in your country first.

 

[nem]

Pulling off the CRT cover is very difficult and it seems like I'm doing it wrong. According to the manual, it pulls straight off after the bolts are removed. But I need to pull very hard to get the top part with the small bumps to separate from the light fixture. I don't see any way to loosen the light fixture to allow the cover to pull away easily. I prefer to remove the entire light assembly with the CRT cover so I can separate them without breaking anything.

There's two screws that hold the s-shaped metal piece (the one with the bumps) to the bottom of the light fixture. The trick is to have these screws a bit loose. Then you can pull the cover off easily.

 

[nonosto]

I changed for LED, japan arcade (ebay seller) in Paris adapt the 100V connector:

 

[Stokers]

Really enjoying this one.. looks great!

 

[Hackcell]

I changed for LED, japan arcade (ebay seller) in Paris adapt the 100V connector:

I'd change the fluorescent on my blast for something more power consumption optimal like a LED... would you mind sharing the seller's link?

 

[nonosto]

if it can help I changed my tube for a LED 100V, one friend succed to connect it with right jst connector I used this for support and LED:

https://store.shopping.yahoo.co.jp/alllight/ulk201b-umedensha.html
https://page.auctions.yahoo.co.jp/jp/auction/l668404008
https://www.arcade-projects.com/thr...ket-for-net-city-marquee-light-fixture.18008/

 

[Fredo]

I'd change the fluorescent on my blast for something more power consumption optimal like a LED

Honnestly, the power consumption of the fluorescent light alone is negligeable.

It would take months for you to get back the money you invested on moving to LED.

And as it's no longer the original stuff, one could consider your cab lost some value in the process.

Not a great plan IMHO.

 

[nonosto]

I kept the original part in case of, but parts who could decrease value are repro stickers, repro panel, crt burned or changed for another model (to shangai novel 31 )...

 

[Thomas]

I replaced some more capacitors, this time the surface mount electrolytics. I started with the Naomi system, and while it may be a little too early to pull out its capacitors, I did it anyway. This included all SMD electrolytics on the main board, the supercapacitor on the main board, and the single through-hole electrolytic on the filter/connector board. I replaced the supercapacitor with a .47F although I'm not sure what its purpose is since there's already a battery next to it.

I also replaced the electrolytics on the 838-14245 PCB (not sure what this board does exactly, something about Maple conversion) and the I/O board.

I even replaced the electrolytics on the game PCBs which is really not necessary but will be one day. The PCBs all had a lot of dirt collected where the cartridge case vents are located.

Out of curiosity I checked voltages on a game's ROMs while I had the Naomi disassembled to see how much voltage is dropped between the Naomi system and a game. Voltage on Power Smash ROM ICs was 4.88v. I then cleaned all contacts on the game, Naomi, and Naomi filter/connector board with Deoxit and isopropyl alcohol, then checked voltage again. Still exactly 4.88v. I turned the 5v supply back up to 5.1v (from 5.04v) when measured on the Naomi power connector.

Next I put new thermal pads on the processors.

 

[Thomas]

For the CPU fan, I installed a CUI CFM-4010V-058-206-20 which is a 40mm fan and the mounting holes don't line up with the CPU heatsink. I must have known this when ordering and decided I would figure it out later. I checked to see what other people have installed and the Noctua NF-A4x10 5V seems to be the popular choice. I would have used the Noctua fan instead but it is also a 40mm size and also has the problem of the mounting holes not lining up with the heatsink. So I stuck with the CUI fan which, according the data sheets, is slightly louder than the Noctua but provides greater airflow.

The original fan blows air down against the heatsink, and in some photos I've seen online of Noctua fans installed in Naomis, the fan is positioned to blow upward away from the heatsink. The Notcua fan, and my CUI fan, should be installed with the label facing down.

I used adhesive silicone to attach the fan to the heatsink.

I wanted to install a 50mm fan for greater airflow and/or lower noise, and also be able to attach it to the heatsink with screws. I found one (CFM-5010V-043-260) that has mounting holes that line up with the heatsink holes, but when double checking to see if it would fit before ordering, I saw that there's only about 1mm of space between the 45mm heatsink and the side of the game cartridge (if the heatsink was taller). This means a 50mm fan would need to be offset on the heatsink by about 5mm, which would eliminate the option to attach the fan with screws, or the heatsink would need to be offset on the CPU by 5mm, which would be sloppy and maybe affect cooling capability.

For the Naomi case fan I installed a Sunon.

With three fans operating inside the Net City I can definitely hear the fan noise still, but it's not a problem for me. The fans are the only moving parts inside and the sound makes it feel like an arcade "machine". The CPU fan is still the noisiest but it isn't as loud or high pitched as the original fan, which was really generating a lot of noise. And of course the fan noise is completely masked by the game audio playing through the extra loud speakers.


The player 1 control wire harness that came with the cabinet had some wires with damaged insulation and a few other things that gave me a bad vibe, plus I needed a player 2 harness, so I made all new harnesses for the controls.

 

[Adrick]

For the CPU fan, I installed a CUI CFM-4010V-058-206-20 which is a 40mm fan and the mounting holes don't line up with the CPU heatsink. I must have known this when ordering and decided I would figure it out later. I checked to see what other people have installed and the Noctua NF-A4x10 5V seems to be the popular choice. I would have used the Noctua fan instead but it is also a 40mm size and also has the problem of the mounting holes not lining up with the heatsink. So I stuck with the CUI fan which, according the data sheets, is slightly louder than the Noctua but provides greater airflow.

The original fan blows air down against the heatsink, and in some photos I've seen online of Noctua fans installed in Naomis, the fan is positioned to blow upward away from the heatsink. The Notcua fan, and my CUI fan, should be installed with the label facing down.

I used adhesive silicone to attach the fan to the heatsink.

I wanted to install a 50mm fan for greater airflow and/or lower noise, and also be able to attach it to the heatsink with screws. I found one (CFM-5010V-043-260) that has mounting holes that line up with the heatsink holes, but when double checking to see if it would fit before ordering, I saw that there's only about 1mm of space between the 45mm heatsink and the side of the game cartridge (if the heatsink was taller). This means a 50mm fan would need to be offset on the heatsink by about 5mm, which would eliminate the option to attach the fan with screws, or the heatsink would need to be offset on the CPU by 5mm, which would be sloppy and maybe affect cooling capability.

For the Naomi case fan I installed a Sunon.

With three fans operating inside the Net City I can definitely hear the fan noise still, but it's not a problem for me. The fans are the only moving parts inside and the sound makes it feel like an arcade "machine". The CPU fan is still the noisiest but it isn't as loud or high pitched as the original fan, which was really generating a lot of noise. And of course the fan noise is completely masked by the game audio playing through the extra loud speakers.


The player 1 control wire harness that came with the cabinet had some wires with damaged insulation and a few other things that gave me a bad vibe, plus I needed a player 2 harness, so I made all new harnesses for the controls.

838-14245 It is to manage the card readers the nnc don't usually have it unless they put a konami type cpo or taito Ect... on the other hand nc did have a cpo with card reader for one player.



I really like the way everything is looking very tidy.

Where did you get electrolytes and capacitors for spare parts?

 

[JoeAwesome]

What kind of stick mount setup is that @Thomas

 

[Thomas]

838-14245 It is to manage the card readers the nnc don't usually have it unless they put a konami type cpo or taito Ect... on the other hand nc did have a cpo with card reader for one player.



I really like the way everything is looking very tidy.

Where did you get electrolytes and capacitors for spare parts?

I thought it might be for different controls like analog or light gun. There's also two other connectors in there that I assume are for different controls too. It's not explained in the manual. The cabinet came with an Aime card reader but not connected to anything and the connectors look different. I think the guy who sold the cabinets to me took control panels from other cabinets and put them on mine.

I buy all of my electrolytic capacitors and other parts from Digikey.

What kind of stick mount setup is that @Thomas

Player one is a Seimitsu LS-40 with an SS plate (LS-40-01-SS). Player two is a Seimitsu LS-55 with a Kowal Flat Plate Converter. The standard flat plate sold with the LS-55 is the MS P-40 and it doesn't fit alberto1225 panels. I could use an SS plate, SS P-40, but I like a shorter distance between the panel and the balltop so I'm using the Kowal plate. I've tried both the LS-55 and LS-56 with the SS plate and it places the balltop too high in my fingers/hand. So far I don't really like the LS-55 because it springs back to neutral too strongly. It has a very different feel compared to other Seimitsu levers. It also makes a loud thumping sound that I find annoying.

 

[Thomas]

There's two screws that hold the s-shaped metal piece (the one with the bumps) to the bottom of the light fixture. The trick is to have these screws a bit loose. Then you can pull the cover off easily.

I loosened those screws so now I can remove the CRT cover more easily. I'm realizing that it's a bit of a chore to get access to the monitor because the front panel needs to come off first to disconnect the speakers. Still, it's nice to have access to the chassis and tube without removing the monitor from the frame.

It seems unusual to me that Sega would intentionally design the light bracket s-shaped part so that the screws need to be slightly loose because they could become even more loose during transit. When I received the cabinet the screws were very tight so someone before me must have tightened them.

With the front panel off it is possible to loosen the screws with an angled driver with a bit that's just the right length, so that's another option.

@nem also solved the mystery of the "cushion sponge 580" (it fits in the back between the two metal pieces that make up the billboard holder). I thought this sponge might be related to the CRT cover or front panel but it's not. The space between the two metal pieces on my cabinet is already tight and I can't think of a reason for adding any foam there so I left it alone. I would need to buy some new foam that is very thin as well.

I did add some foam all around the outside of the monitor screen to fill some gaps between the glass and bezel. I could see adhesive residue around the perimeter of the glass and there was a huge mess of disintegrated foam covering the inside of the control box so I think the monitor used to have foam around it. There was a significant gap on the left side but once I tightened all the front panel bolts the bezel became mostly flush against the glass with only a minor gap along the bottom and top. The foam will keep dust from accumulating inside the control box.

The screw caps that I bought from Arcade Invaders were very tight when I put them on the front panel and I couldn't push them in far enough to be flush. The main problem with this is that when I need to remove them in the future it will be very difficult to do so without breaking them and scratching the front panel. Fortunately I did a test fit with the front panel off the cabinet so I was able to push the caps back out with a screwdriver from behind.

To make the caps easier to install and remove I sanded down the narrow space in the center.

I also sanded off all of the paint that was sprayed on the end tabs because that was also interfering with pushing the caps in flush. Now the caps are easy to remove with a small screwdriver.

I sanded and polished the bezel/mask the same way I did on my Blast City and Astro City. Polishing was even more difficult than the Astro and Blast bezels because the edges are more sharp. I did some hand polishing around the insides since buffing pads, even 1" pads, catch on the bottom edge and will tear off the paint.

The grey color doesn't quite "pop" like black.