Naomi boot issue please advise

[KOarcade]

hey guys. I've never seen this before in the year I have had these system. Booted fine this afternoon and now I'm getting this weird garbage " F. FGFG) on the screen at the beginning of boot. See picture and if someone has any input on what they think is wrong and how to fix. I have even tried booting a cart and nothing happens during boot. With the netdimm installed I get this...

My setup
Naomi 1
Netdimm 512mb w/ multi bios
Raspberry pi 3 w/ wireless netbooting
Capcom io board
Suns psu

Again I've had this for little over a year now.

 

[LazerFlux]

Maybe your BIOS or related settings went bad? I'm not too knowledgeable about the platform, but that's my educated guess. Can you boot into test mode?

 

[skate323k137]

I shot you an email man. If you want to try a new bios I'll send you one at cost. Can't hurt to try.

My other ideas were check around the supercap for leaks, and see if you can run the test mode diagnostics.

 

[KOarcade]

okay here are some screen shots that i have been meaning to upload. hopefully someone has seen this. Image bottom left is the first boot screen. Image top left is load game from RasPi3 to netdimm. Image top right is loading game from netdimm to naomi. Then after finishing loading it just gets to the normal Naomi screen as though it is going to start the game finally and NOTHING!!! It just sets there.

Here is what happened. I was testing out monitor and a projector.I decided to test the video devices while the naomi was live during its initial boot screen had finished loading. Everything was cool. I booted and played CvS2 on a monitor and then directly to a projector. Again without shutting down the setup. It worked fine. My friend and I shut it down and now I get these garbage screens. Fortunately enough, I have a second naomi setup. Exactly same setup as mine that I have been putting together for a friend. I tested his netdimm, raspi3, and IC bios (japanese) from his setup on my naomi board. I still get garbage letters only they are like C...CC...B...blah blah. I reverse the test and use my netdimm, raspi3 on his and everything worked fine. I did not try my IC on his board in fear of something possibly harming his naomi board. I would love to take my IC bios and put it in his and attempt a full boot. Just a little scared. I still may do it today just to see what happens. After I have finished all of my tests I am still concluding that it is the naomi which has slightly malfunctioned so how. IDK??? Could it be the IC bios that went bad because I was unplugging a VGA cable?? I mean it is just a video signal wire. I really cannot imagine that something as little a switch a source to new device would cause any harm? But this is arcade hardware we are talking about. Gotta love it.

 

[skate323k137]

Hot swapping displays is one of those things that usually won't cause issues, but electrically, it definitely can be a problem.

If it were me I'd humor myself with a different bios and maybe different filter board, but if that doesn't fix it then you're probably right that it's the NAOMI mainboard.

 

[obcd]

Problems with switching displays live are the GND connection of them. If the voltage between the GND connections is different, and the GND is not the first thing that connects, than that voltage searches it's way trough the chips to GND and that can damage the system.

To avoid such issues, you should always connect all devices their GND to each other and leave that connected.

Most TV sets for instance are not grounded with their mains plug. This means that you can have up to 100V AC on the chassis of the TV. If the naomi is connected to a properly grounded supply (which it should be connected 2), it will have 0V on it's GND. Once the connection is made, the voltage on both grounds will become equal. Most circuits don't like 100V AC trough their pins.

So, hotplugging monitors or any devices that are powered separatly and might have a different ground voltage should be avoided at all time. At least disconnect the power plug on one of the devices and preferrable disconnect the power on both.

 

[KOarcade]

ok, i really appreciate everyone's input.

I took my IC bios and put it into my friend setup and it worked fine. So that chip is okay. There were no random letters or garbage lettering going on at the bottom of the screen.

I changed out filter boards from another naomi and still received the garbage lettering at the bottom of the boot screen. So after testing everything that I have available to interchange. I would again have to conclude that the board took a shock while swapping out video devices and hurt the inner workings of the naomi itself. Anyone know if Ken is still looking at these things or I am just better off trying to buy another main board? booooo :0 Damnmit. Let this be a lesson for myself. boooo. thanks again people.