What's new

[Repair Log] Sega Naomi

Hi. I photographed the damage on the board. Do you know what this contact affects/means, what is it for? Naomi still working. Most likely it appeared when I wanted to connect Naomi to the TV through a chinese adapter (vga to hdmi). There was a burning smell. I immediately turned off Naomi. Then I connected it back to the old TV and everything seems to work. but at that moment my sf card 1gb Sandisk stopped loading almost all naomi/aw games. it only runs dolphin blue and some naomi games. I don't know if this is a coincidence or not.
 

Attachments

  • 65816E27-0013-404A-8753-A7F0C2A82BDB.jpeg
    65816E27-0013-404A-8753-A7F0C2A82BDB.jpeg
    130.1 KB · Views: 182
  • 92A9BE08-80C3-46B0-964B-99EC73D1906B.png
    92A9BE08-80C3-46B0-964B-99EC73D1906B.png
    452.6 KB · Views: 180
  • 0FB64A82-C074-4223-9A51-DFB1419653A3.jpeg
    0FB64A82-C074-4223-9A51-DFB1419653A3.jpeg
    182.3 KB · Views: 187
  • 4FE8C69B-13B8-4973-AB7C-D94C5B5F517F.jpeg
    4FE8C69B-13B8-4973-AB7C-D94C5B5F517F.jpeg
    239.6 KB · Views: 193
I also wanted to ask about Dimm, I found damage. can they somehow influence?
 

Attachments

  • 0347801F-FC4E-44A9-98DC-8793E83B72B2.jpeg
    0347801F-FC4E-44A9-98DC-8793E83B72B2.jpeg
    162.5 KB · Views: 190
  • 5521A255-D92C-48A9-B05C-98362D6ADBB1.jpeg
    5521A255-D92C-48A9-B05C-98362D6ADBB1.jpeg
    228.9 KB · Views: 183
I think you need to get a new DIMM and maybe a new NAOMI. Looks like a lot of current has gone places where it should not.
 
Last edited:
That's what happens when you hook up to something that has a live chassis. This is the kind of damage seen when an arcade game board is hooked to a monitor in a cabinet that requires an isolation transormer, but doesn't have one installed. It feeds voltage back through the video cabe linto the PCB and does damage.
 
I think you need to get a new DIMM and maybe a new NAOMI. Looks like a lot of current has gone places where it should not.
((((.

Ps
 

Attachments

  • 0782F2BF-4C56-4460-9104-FDC75510C024.jpeg
    0782F2BF-4C56-4460-9104-FDC75510C024.jpeg
    155.9 KB · Views: 158
  • 8ABE119D-1371-4C30-AD85-750F80F2D2AA.jpeg
    8ABE119D-1371-4C30-AD85-750F80F2D2AA.jpeg
    169.9 KB · Views: 164
Where is the supercap located?

The mobo has a sticker stating "danger of explosion if the battery is replaced incorrectly". What can explode?

TiA
 
A new one to add to the repair log / list, haven't seen this one before.

Naomi 1 boots up but gets stuck on error 1 and test switch doesn't work, dip switches are also stuck on. Traced the dip switches all the way to the other end of the board to a 315-6146 custom chip. Thankfully the issue was the ram IC46 (62256) used by the custom and not the custom chip itself. Original ram was 70ns, I only had a 100ns ram on hand but it seems to work fine with the slightly slower one.
 
Naomi 2 boots normally, but after seeing the Naomi2 logo, it goes into infinite reboot. It is the same whether the cartridge is inserted or not. Even if you press the test button, it does not enter the test menu and reboots as well. I suspect that the IC30 Altera chip is defective. Any ideas?
 
Is Ken still active here? Got an Naomi 1 Rev. D board with all factory repairs except the one that runs to the Diode and the X76F100, both Fans spinning but not booting. All voltages are good and most importantly the LED's DO NOT LIGHT UP! What could this be? IC 41 and Bios are all good and have connection.
 
Check the voltage test pads in the corner of the board to see what voltage(s) you're missing.
 
Naomi 2 boots normally, but after seeing the Naomi2 logo, it goes into infinite reboot. It is the same whether the cartridge is inserted or not. Even if you press the test button, it does not enter the test menu and reboots as well. I suspect that the IC30 Altera chip is defective. Any ideas?
Self answer:
It works well after replacing some of the main RAM near the CPU.
 
Hi, I am trying to figure out if the impedance between the V3.3 and GND2 test points on the Naomi2 (in corner of the pcb) really is close to zero - or if I could have a short.

Does anyone have a N2 mainboard at hand and could help me with a quick measurement?
 
Back
Top