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If you get a black screen with no sound and no video, I believe its the gpu closest to where the cart inserts. Take the cover off the board, get something firm to press and hold down firmly on one corner of the gpu at a time. (Sometimes the heat sink will pop off or up but this will work) iif it comes off, it comes off.

While you have it held turn on the power and keep it held. There is usually only 1 corner on the gpu that comes up off the board on naomi and if/when you hold it down with a lot of pressure and flip the switch youWill eventually see the logo and hear the sound.IF you take your hand up off the corner however the system will lock up.

Contrary to belief, Naomi systems with black screens and no sound can actually be revived unlike the Chihiro

Try it for yourself and watch it fire up :thumbup:
 
ok short update from me - got my sun psu, a stepdown converter and a psu cable made by @Mitsurugi-w, now my piboot-setup works again :thumbup:

however the virtua tennis cart i bought for testing still doesn't work, rom test looks like this:


could there be a problem on ic22, if so could somebody help me out with a replacement?

and two other questions, i'm wondering if i should recap my sun psu an change the supercap on the naomi2 mobo... should i do it should i look out for something special to see if it is needed?
 

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If your psu isnt putting out enough power you will have problems with the game starting. You may get the Naomi logo and the Now Loading, even get to the "this game only for use in Japan" etc but it wont boot. If you have a multimeter, turn the voltage pot on the psu up to make sure it is putting out 5v, 3.3, and as close to 12 as possible and try again. My guess is that it isnt getting enough power to start. Look for the small screw hole on the side of the psu and with a small screwdriver adjust it :)

Good luck
 
i checked the outputs of the psu,

12v line -> 12.25v out
5v line -> 5.12v out
3.3v line -> 3.33v out

i'll try if ajusting helps...
 
i only dialed down 5v to 5.03, the virtua tennis cart still doesn't work

is there anything i have to change when going from netdimm to a normal cart?
 
1. take a look at the bottom of the cart and the white clips that go into the naomi. Make sure that none of the pins inside are bent or missing which sometimes happens from forcing the cart in or trying to put it in the wrong way.

2. another thing to do is look at the pins of the surface mounted chips on the bottom if there are any. check that none are broken away from the board or bent. this happens from time to time due to mishandling.

3. Remove the 2 screws holding the game pcb inside the plastic case. There should be a socketed eprom inside it. The legs on those sometimes become corroded and wont work until cleaned. remove the eprom, clean the legs, reinsert and check.

hope that helps
 
Another thing to remember is that with some Naomi games they will require a certain bios to work. Some games wont work without an H bios and if you have an E bios it may not boot. Look at your bios and the letter on it and see what you have. If you have the ability to do so, burn another bios and try that.

The thing with Naomi's is there are so many things that can be an issue with them that you have to start and check one by one until you find the problem. Ive only listed a handful of the problems Ive found on the 100+ Ive owned and repaired.
 
first @lukemorse1, thanks for your help!

The contacts on the bottom seem to be ok, on the bottom side no chips are attached. the contacts on rom 12 position look funny, but everything is unpopulated and not looking like something is missing.

On the upper side of the cart there is some dirt on IC1, and the eprom on IC22 is the only one without a result in the rom board test i posted in post 21 on this thread, even after cleaning.

As for the bios, i have a multi bios installed, sorry i can't be more specific because that's all i found. Also unfortunately i don't have the means to burn another bios myself.

Now when booting i get the naomi logo, then a black screen with "LOADING VIRTUA TENNIS (31K)".
After that the screen stays black, no sound, entering test menu not possible at that point.

When i enter the test menu before that i can rom check the cart (pic in post 21), when i try to enter the submenu of the cart for the game settings the system freezes.

Later i'll try to reflow the eprom socket, otherwise i think it's the eprom itself...
 
If it is getting that far then it may be the Ram itself on the motherboard that has failed. do you have any other games you can check? Depending on the game, even if some parts of the motherboard arent working to spec the system will still play some games.

For example. I had a naomi that wouldnt play WWF at all. it went to the Naomi logo then black screen and froze. if you went into the test menu you could see it recognized the rom board and even would do a rom check but came back with 2 ICs bad (same as yours). The game (WWF) when played on another system would play fine without any issues at all. When I went back to the half assed working Naomi again, I tried the system with a Jambo Safari or Cosmic Smash and it would boot the game no problem but without sound. These are some signs that some of the ram is bad on the board.
 
i only other thing to test is the netdimm which now works again perfectly since i got my sun psu ... i tried about 10 diffenent games (Naomi, Naomi2 and AW2Naomi)
Funniliy enough virtua tennis on netdimm works perfectly...

one funny thing i forgot the other post - sometimes the virtua cart does not stop with a black screen - sometimes it stops with a mirrored sega logo ?( IMG_0738.JPG
 
Can anybody advise another chip equivalent to D4564323G5 for IC 106/7 Trying to get hold of a few; attempting to resurrect a Naomi 2 Mobo.

I have completely black screen. No sound and all voltages are correct.

Look on Google for the following. I have some winging their way to me. They look pin compatible.

10PCS W9864G2GH-7 W9864G2GH7 W9864G2GH W9864 TSOP86 new original In Stock
 
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i only other thing to test is the netdimm which now works again perfectly since i got my sun psu ... i tried about 10 diffenent games (Naomi, Naomi2 and AW2Naomi)
Funniliy enough virtua tennis on netdimm works perfectly...

one funny thing i forgot the other post - sometimes the virtua cart does not stop with a black screen - sometimes it stops with a mirrored sega logo ?( IMG_0738.JPG
This EXACTLY happened to my virtua tennis cart - never figured it out... the naomi was perfectly fine though - so the cart must have died on me.

Matt
 
nobody so far said something about that particular symptom... - what i saw when i opened it up again is that there's jumper next to eprom - i wonder what that does?

i know it's not the most valuable cart but that on the other hand makes it a perfect object for learning and i haven't given up on it yet...
 
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