Blast City Club

cornerstone

King's Dry Cleaner
Joined
Sep 13, 2013
Posts
384
adf4539f445a396c2012e69479fcb79d.jpg


I do have this sheet, which would indicate to look at the power circuit it self. Is that something I can do with a simple multimeter?
 

djjimmyjames

NG.com Tattoo Artist.,
Joined
Jul 24, 2005
Posts
932
You have red missing so it’s either a capacitor/part issue or something. You’ll have to pull the monitor out you can use the power cord from the cab just keep it close. This way you can diagnose the problem . I would wash the monitor and the board and completely clean the cab with simple green and a bucket of water. Make sure you discharge everything. If not capable of fixing and diagnosing Send the chassis to sharp and pay the $200 to diagnose, fix and replace caps.



I replaced a heater resistor and still have to do a cap kit and mess with the convergence. I’m running a 2932 so 31k only.
I have a 2931 in the works.
DFBC2432-D200-4DDC-AE08-4C41313DE7FD.jpeg
3CB4CBE7-3050-4D69-801D-89AF8ABFF77F.jpeg
 
Last edited:

cornerstone

King's Dry Cleaner
Joined
Sep 13, 2013
Posts
384
Sorry for taking up this thread with my chassis issue, but are these three solder points underneath the flyback supposed to be unsoldered?

6a1a86448f69852927d5228d06fc9242.jpg


There’s no pad for them underneath but I can’t find any other similar examples of pins just going through the board like that.
 

NERDtendo

Big Bang Pro Wrestler
Joined
Jul 6, 2013
Posts
876
Grabbed on piece of a VS kit for the Blast City...now just gotta track down the rest of the parts.

 

NEgO MANIAC

Benimaru's Hairdresser
Joined
Jan 5, 2004
Posts
793
I've been trying to figure out why my Blast City has a blurry screen after powering up. I've tried a NANAO 2930 monitor and MS-9 monitor with similar results. I thought it might be the harness connections at the I/O board, but I swapped in a spare harness with the same results. I don't have a spare I/O board so I can't verify if that is it. I thought maybe those old caps on there are dried out. I tried swapping them out, but I have no idea what kind of solder Sega used, but the board is an absolute pain to desolder the caps from. I had to pull the caps off and desolder the legs. Unfortunately it left solder behind in the holes and the solder doesn't want to come out for the new caps to go in. Could use some ideas and now looking for a replacement I/O board.
 

everten

Edo Express Delivery Guy
Joined
Sep 2, 2012
Posts
342
Does anyone know if you can remove the blast city speakers without removing the monitor?
 

everten

Edo Express Delivery Guy
Joined
Sep 2, 2012
Posts
342
Still no easily compatible replacement on the speakers? I found some old Sony side mount speaker bars that I’m hopefully have similar size speakers.
 

ChuChu Flamingo

We have purposely, trained him wrong, ...as a joke
Joined
Nov 23, 2010
Posts
2,357
I've been trying to figure out why my Blast City has a blurry screen after powering up. I've tried a NANAO 2930 monitor and MS-9 monitor with similar results. I thought it might be the harness connections at the I/O board, but I swapped in a spare harness with the same results. I don't have a spare I/O board so I can't verify if that is it. I thought maybe those old caps on there are dried out. I tried swapping them out, but I have no idea what kind of solder Sega used, but the board is an absolute pain to desolder the caps from. I had to pull the caps off and desolder the legs. Unfortunately it left solder behind in the holes and the solder doesn't want to come out for the new caps to go in. Could use some ideas and now looking for a replacement I/O board.

Try adding flux and reflowing some new solder. Seems retarded but it helps transfer heat better. I've read these boards like to suck up a lot of heat due to the ground planes.
 

lachlan

The Woozy of Oz
Joined
Feb 13, 2005
Posts
18,665
Sorry for taking up this thread with my chassis issue, but are these three solder points underneath the flyback supposed to be unsoldered?

6a1a86448f69852927d5228d06fc9242.jpg


There’s no pad for them underneath but I can’t find any other similar examples of pins just going through the board like that.

Yes, as you can see there are no solder pads on the underside for those pins. From my experience with 2930,31 and 32 chassis and photos of the others, there are no solder pads on the component side either. You are safe!
 

everten

Edo Express Delivery Guy
Joined
Sep 2, 2012
Posts
342
I found a nice way to move the monitor remote board to be more easily accessible. You just need 4 x PCB feet (2 screwed together back to back on each side), and remove the metal bracket under the control panel or you will damage the board when mounting this way.

Front view:
49742788987_4ec2ea4e15_z.jpg


Top view:
49742789002_4de94877bc_z.jpg


Back view:
49742465346_c997557aeb_z.jpg


IMPORTANT! Remove this bracket or you will shear off your remote board pots:

49742464906_bb2f29fafe_z.jpg
 

Stellarola

Fio's Quartermaster
Joined
May 3, 2005
Posts
490
I've been trying to figure out why my Blast City has a blurry screen after powering up. I've tried a NANAO 2930 monitor and MS-9 monitor with similar results. I thought it might be the harness connections at the I/O board, but I swapped in a spare harness with the same results. I don't have a spare I/O board so I can't verify if that is it. I thought maybe those old caps on there are dried out. I tried swapping them out, but I have no idea what kind of solder Sega used, but the board is an absolute pain to desolder the caps from. I had to pull the caps off and desolder the legs. Unfortunately it left solder behind in the holes and the solder doesn't want to come out for the new caps to go in. Could use some ideas and now looking for a replacement I/O board.

You should use low melt solder and flow it onto the components, this in addition to flux will make your life 1000% better.

https://www.amazon.com/FAST-CHIP-Re...eywords=low+melt+solder&qid=1589215072&sr=8-4

https://www.amazon.com/MG-Chemicals...?dchild=1&keywords=flux&qid=1589215087&sr=8-3
 

Stellarola

Fio's Quartermaster
Joined
May 3, 2005
Posts
490
I’ve reseated the connector with no change. The absence of red is in both 15khz and VGA mode.

I wonder if I could unseat the connector, run a wire from the blue output on the vga pcb to the red input on the chassis? Would that turn everything that’s supposed to be red to blue?


That might determine if it’s a wiring issue possibly

Do a continuity test from the neckboard with your multimeter to see if there is an issue with the connection
 

cornerstone

King's Dry Cleaner
Joined
Sep 13, 2013
Posts
384
Do a continuity test from the neckboard with your multimeter to see if there is an issue with the connection

So I send the 2930 chassis back to the vendor and it now runs. It took a while, but it actually comes on and displays all the colors.

It is quite dim though. I’ve done the standard adjustments to contrast, screen and brightness. Brightness is maxed out and contrast is up there.

I’ve verified the monitor dips are correct, and the 31khz vga cable is disconnected.

Is there another pot I maybe should be messing with?
033b4a3f3b24005f74f30d87ba7d41fe.jpg
 

BanishingFlatsAC

Psycho Soldier
Joined
Mar 8, 2006
Posts
4,651
So I send the 2930 chassis back to the vendor and it now runs. It took a while, but it actually comes on and displays all the colors.

It is quite dim though. I’ve done the standard adjustments to contrast, screen and brightness. Brightness is maxed out and contrast is up there.

I’ve verified the monitor dips are correct, and the 31khz vga cable is disconnected.

Is there another pot I maybe should be messing with?
033b4a3f3b24005f74f30d87ba7d41fe.jpg

Did they replace the flyback?
 

radiantsvgun

So Many Games. No Time. For Harlots.
Joined
Sep 29, 2007
Posts
1,619
So I send the 2930 chassis back to the vendor and it now runs. It took a while, but it actually comes on and displays all the colors.

It is quite dim though. I’ve done the standard adjustments to contrast, screen and brightness. Brightness is maxed out and contrast is up there.

I’ve verified the monitor dips are correct, and the 31khz vga cable is disconnected.

Is there another pot I maybe should be messing with?
033b4a3f3b24005f74f30d87ba7d41fe.jpg

Was the tube/yoke originally a 2931? If so, there will be some brightness and focus issues.

It’ll work, but you’ll always have brightness issues- I have a 2931 on a 2930 tube and it does the same. Tried 2930 on 2931 tube and also had the same issues.

If they’ve replaced the caps too, you might have to do a full retweak of it. Flyback adjustments, ect.
 

cornerstone

King's Dry Cleaner
Joined
Sep 13, 2013
Posts
384
The tube does have a 2930 sticker on it, so I may be in luck on that.

It does look like some caps changed at least. Is there a general guide that people use to get their monitors back up after repairs?

I’m reading about B+ voltage adjustments, but I’d need to know where to measure that.
 

radiantsvgun

So Many Games. No Time. For Harlots.
Joined
Sep 29, 2007
Posts
1,619
The tube does have a 2930 sticker on it, so I may be in luck on that.

It does look like some caps changed at least. Is there a general guide that people use to get their monitors back up after repairs?

I’m reading about B+ voltage adjustments, but I’d need to know where to measure that.

The majority of chassis I’ve gotten or capped myself will need adjustments after fresh caps. One of the things you’ll have to do is adjust the flyback. There are two pots on there for brightness and focus.
 

cornerstone

King's Dry Cleaner
Joined
Sep 13, 2013
Posts
384
The majority of chassis I’ve gotten or capped myself will need adjustments after fresh caps. One of the things you’ll have to do is adjust the flyback. There are two pots on there for brightness and focus.

Yeah so I’ve got that part. I’ve got the SCREEN turned up to just barely see the jailbars, while contrast and brightness on the front adjustments are almost maxed out. And it’s still dark.

Are there any other pots to move?
 

cornerstone

King's Dry Cleaner
Joined
Sep 13, 2013
Posts
384
So there’s a pot next to the color pots that adjusts the overall color levels. I hit it accidentally and I learned something new. Brightness and color levels are good now.

New question:
Is there a way to funnel the stereo sound in without a 001 loom? Or to possibly create the audio part of the loom?

I have a Dreamcast vga box setup and I need to route the audio to the I/O board or somehow reach the speakers.
 
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