Naomi won't boot - looking for ideas

OldFoo · Post by **OldFoo** » Sat Dec 13, 2008 4:57 pm

will go over the pins with some alcohol, would that affect things when no cart is in it though? I assume not, even with no cart it doesn't boot to the white screen regularly.

grantspain wrote:
scogon wrote:
grantspain wrote:meter at the mobo input plugs not the I/o

white is ground,yellow is +5 and brown is 3.3

ok got it...

3.26v, 5.08v, and 11.87v

should be o.k tbh,maybe you have a dirty pin on the cart

OldFoo · Post by **OldFoo** » Sat Dec 13, 2008 5:14 pm

ok the mobo should boot to an error without a cart every time,sounds like it could be this cap battery problem

does it do a particular sequence every time or does it stop randomly

OldFoo · Post by **OldFoo** » Sat Dec 13, 2008 5:40 pm

grantspain wrote:ok the mobo should boot to an error without a cart every time,sounds like it could be this cap battery problem

does it do a particular sequence every time or does it stop randomly

When it boots up it's solid and plays fine till I turn it off, though I never left it on for a day or anything to see what happens. When it doesn't boot, there is nothing on screen, the fan on the mobo comes on and that's it.

The voltage readings I got were on a failed boot attempt, it hasn't booted this morning, when/if it does again I'll take readings and report them.

So you figure there is a cap I need to swap out? Any info on how to determine this and get replacement cap(s) would be awesome.

OldFoo · Post by **OldFoo** » Sat Dec 13, 2008 6:23 pm

check out channelmanic's guide

http://www.sega-naomi.com/forum/viewtopic.php?t=1949

OldFoo · Post by **OldFoo** » Sat Dec 13, 2008 9:55 pm

well I opened it up, looked over the motherboard, it is quite clean, no visible issues at all really, nothing leaking or anything. Bought another motherboard, will try it out once I get it, hope this gets sorted out that easily!!

OldFoo · Post by **OldFoo** » Sat Dec 13, 2008 10:05 pm

naomi 1 are so cheap tbh its not worth messing around,i have about 8 for my spares and will stock up with another 10 as soon as

OldFoo · Post by **OldFoo** » Mon Dec 15, 2008 11:21 pm

Post a close-up picture of the memory backup capacitor. It's inbetween the BIOS chip, the 8 pin EEPROM, and the battery.

I'd like to see if the solder on it is nice and shiny like IC29 next to it.

RJ

OldFoo · Post by **OldFoo** » Wed Dec 17, 2008 6:51 pm

channelmaniac wrote:Post a close-up picture of the memory backup capacitor. It's inbetween the BIOS chip, the 8 pin EEPROM, and the battery.

I'd like to see if the solder on it is nice and shiny like IC29 next to it.

RJ

thanks for looking in on this channelmaniac, will get a pic and post it soon.

OldFoo · Post by **OldFoo** » Thu Dec 18, 2008 1:05 am

well that didn't work, my camera suck and all close up pics were quite blurry, had to try and use my phone camera because the good one crapped out a few months ago.

I did look over the memory back up capacitor (small round thing, black on the outer circle silver in the middle?) it appears to be quite clean, should I be looking at the top of the board or open it up and check the underneath? I hadn't even looked in this area before as the dual bios chip/switch was covering this. After removing it all looks very clean.

OldFoo · Post by **OldFoo** » Fri Dec 19, 2008 10:38 pm

got a new Naomi board, and it appears to work fine so far! So, unless my set up fried my old Naomi board then I can be confident that the problem is/was in the old Naomi.

I may use the switch modded bios in my new Naomi, what the best/safest way to pull these out of the socket? Just use my fingers and keep it level on the way out? is oil from my hands a real concern? noob question I am sure... just curious.