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.
[Repair Log] Sega Naomi
- Thread starter TylerDurden67
- Start date
Get rid of that VGA to HDMI adapter also.
channelmaniac
Professional
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.
StormyNormy
Student
Where is the supercap located?
The mobo has a sticker stating "danger of explosion if the battery is replaced incorrectly". What can explode?
TiA
The mobo has a sticker stating "danger of explosion if the battery is replaced incorrectly". What can explode?
TiA
The battery can explode. When batteries are connected incorrectly, they can overheat or start a fire.
Ace`
Enthusiast
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 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.
WangDrum
Enthusiast
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?
Casselfornia
Student
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.
Ace`
Enthusiast
Check the voltage test pads in the corner of the board to see what voltage(s) you're missing.
WangDrum
Enthusiast
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?
Does anyone have a N2 mainboard at hand and could help me with a quick measurement?
Casselfornia
Student
I can have a look at my board this month.
So, some updates in general:
I have 5 dead Naomi PCB's here.
2x old revision with the second large big heatsink that was used for HotD2 and came with the metal cage
3x newer revision board in plastic housing
I just decided to give it another go and tested all of them. They all check out ok on the connections between the 315-6188 and Alterra. Bios also checked okay. Both fans spinning in all systems. They all boot to a black screen with no sound. On 1 board if I press down on the GPU fan while booting I get some blocky static. This brings me to the conclusion that it would work if I'd change the VRAM. Is there anything else that can be done, except reballing the BGA? Really thinking about getting a Reflow Station for these kinds of repairs but I'm kinda hesistant.
So, some updates in general:
I have 5 dead Naomi PCB's here.
2x old revision with the second large big heatsink that was used for HotD2 and came with the metal cage
3x newer revision board in plastic housing
I just decided to give it another go and tested all of them. They all check out ok on the connections between the 315-6188 and Alterra. Bios also checked okay. Both fans spinning in all systems. They all boot to a black screen with no sound. On 1 board if I press down on the GPU fan while booting I get some blocky static. This brings me to the conclusion that it would work if I'd change the VRAM. Is there anything else that can be done, except reballing the BGA? Really thinking about getting a Reflow Station for these kinds of repairs but I'm kinda hesistant.