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[Repair Log] Sega Naomi

TylerDurden67

TylerDurden67

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After having repaired a lot of Naomi, I share with you the most frequent problems and how to repair it:

General:

N1 or N2
- Does not exceed 5.1V, the buffer chips do not support more, then even if it is less than $1, better to avoid changing by pure luck! Rams aren't supporting more voltage too.
- If a fan is not running (Naomi checked rotating using the 3rd wire), it does not boot for safety. otherwise that kind of stuff can append


- The super-condo 0.1f EECS0HD104H (known by the nickname "c'te bastard ") located in C29.Can be found on Mouser or other website of course.
If naomi does not boot, changing it can help (even a lot! 4 naomi failing, 3 have booted just by changing it!).
His nickname comes from the fact that it tends to be leaks.
On N2 is less problematic (but do not take the problem lightly has, leaks of electrolyzed wreak havoc) on N1, the stream that flows goes under BIOS EPROM and EEPROM as Altera, cutting tracks.
Risk of non boot in the end, and if it starts luckily, there may be a BAD test IC29 (it is not defaulting, you just do what I quoted).

So desoldering, cleaning, redo the tracks.

A small scheme if the tracks are down (or check them)

EEPROM (IC31) -> Altera (IC30)
Pine 1 -> pin 12
pin 2 -> 1 pin
3 pin -> pin 37
4 pin -> 4 pin
pin 5 -> GND
6 pin -> unused
pin 7 -> + 5V
pin 8 -> + 5V

Family Photo (left to right the C29 "c'te bastard")



Naomi 1:

Black screen

several solutions:
-Bios Corrupt or not present
-Fixed CPU had more particularly to the BGA (rare as on the N1)
-supercap (a change or which sank)
-GPU Fan not working


Black screen but with sound
- RAMDAC HS (IC41)


Naomi 2:

Black screen
-Bios Corrupt or not present
-Problems CPU had more particularly to the BGA (extremely rare.changing GPU rams can make itboot)
-supercap (to change or leaked.Less worries than N1, not too many components around)
-GPU Fans not working
- 1 or 2 Mains RAM (IC106 and IC107) is / are dead (s)



has the Common Naomi 1 and 2:

-error 03: the one, it is well
normally the IC31 contains the serial number of board.If it cant be read, error 03.
therefore check as before for the super cap.
Otherwise, another trick: reprogram the BIOS! (I had the case with on a pretty old export BIOS)

-This kind of graphical glitche


and when doing RAM Test,except somes others glitches you got all rams GOOD


Try Changing IC16 (Graphical RAM)

- This one
p1280110.jpg


Simply do a RAM test and the bad one will appears

- this glitch
Naomi_Repair_2.jpg


Just investigate the filter board,specialy the vga connector.


I / O Board
Not detected, malfunctionning, blah

-recurrent, it is ALWAYS the IC02 which is HS (the big black ugly stuff all over support).
So we find on the net, but must reprogram the ...
sells or otherwise gzipuk andy geezer

- somes buttons are pressed.

its just one or somes octoisolators PS2801.
change it by using this pinout.Check between pin depending of your error and all octoisolator.at a moment,it will "beep" and that's this one which have to be changed.

From Andy Geezer
Digital Inputs (60pin AMP RA connector)

01 (+5V)
02 (+5V)
03 (+5V)
04 (+5V)
05 (+5V)
06 (+5V)
07 (+5V)
08 (+5V)
09 (GND)
10 (GND)
11 (GND)
12 (GND)
13 (GND)
14 (GND)
15 (GND)
16 NC
17 (1P Start)
18 (2P Start)
19 (1P Right)
20 (2P Right)
21 (1P Left)
22 (2P Left)
23 (1P Up)
24 (2P Up)
25 (1P Down)
26 (2P Down)
27 (1P SW1)
28 (2P SW1)
29 (1P SW2)
30 (2P SW2)
31 (1P SW3)
32 (2P SW3)
33 (1P SW4)
34 (2P SW4)
35 (1P SW5)
36 (2P SW5)
37 (1P SW6)
38 (2P SW6)
39 (1P SW7)
40 (2P SW7)
41 (1P Service)
42 (2P Service)
43 (Test Sw)
44 (Tilt Sw)
45 (Coin SW1)
46 (Coin SW2)
47 NC
48 NC
49 (Coin Meter 1)
50 (Coin Meter 2)
51 (Output 1)
52 (Output 2)
53 (Output 3)
54 (Output 4)
55 (Output 5)
56 (Output 6)
57 (+12V)
58 (+12V)
59 (+12V)
60 (+12V)


That's all for now.
 
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Excellent thread!

I have a strange problem with my NAOMI 2, maybe you've seen it.

Will boot with no cart, and enter test menu fine.
Will boot with cart and play.

When booting with Net-Dimm it will keeping "checking network" and never find it.
Entering test menu with Net-Dimm installed there are no options for network.

The same Net-Dimm works fine in my NAOMI 1, I can enter Test-Menu and adjust network options, and net-boot games without problem.

My initial thought would be incorrect BIOS, but I thought all NAOMI 2 bios versions supported Net-Dimms.
 
did your jumper on daughter board configured on netdimm or Gd-rom mode?

Gdrom mode is like this
Jumper_GDROM.jpg
 
TylerDurden67 said:
did your jumper on daughter board configured on netdimm or Gd-rom mode?

Gdrom mode is like this
Jumper_GDROM.jpg
Click to expand...
it's set to Net-Dimm. The NAOMI 2 knows that it's in net-dimm mode, as it tries to find the network, and like I said, it can netboot games and shows the network menu when installed on my NAOMI 1. I have two different fully working Net-Dimm boards and both of them work fine on the NAOMI 1 and exhibit this behavior when installed on the NAOMI 2... so all evidence points to this being a problem with the NAOMI 2 itself.
 
strange.
Anyway my netdimm display network system even in gdrom mode... Maybe too many experience on it :D

Which naomi2 bios did you have?
Have you tried on n2 to reset dimmboard and reconfigure network settings? BTW thoses settings are stored on the dimmboard
 
TylerDurden67 said:
strange.
Anyway my netdimm display network system even in gdrom mode... Maybe too many experience on it :D

Which naomi2 bios did you have?
Have you tried on n2 to reset dimmboard and reconfigure network settings? BTW thoses settings are stored on the dimmboard
Click to expand...
Interesting. Bios version is "EPR 23607" that's all there is on the chip, there is no letter on the end.
 
it's an us bios, last letter should be B.

Strange anyway. If your network is OK, it should work.
Bios is only important for the game region
 
Wouldn't hurt to try a new bios chip. Even if you just need to reburn the same image.
 
TylerDurden67 said:
Mitsurugi-w said:
Wouldn't hurt to try a new bios chip. Even if you just need to reburn the same image.
Click to expand...
yeptry burning an multibios in case of.
you can change between us japan and export
Click to expand...
Just an update, I burned p1pkin's NAOMI2 Rev C Muli-Region bios last night and it worked perfectly and fixed my Net Dimm problems. (though now my NAOMI 2 doesn't recognize my JVS I/O board, though I'm wondering if it doesn't supply power via USB like the NOAMI1 does, I haven't played around with it much yet)

Doing a little reseach on NAOMI2 bioses, there's "no rev" then Revs A, B and C, I had the "no rev" version, which doesn't support the networking card. I wasn't able to confirm but it's possible that it doesn't fully support Net Booting either, or maybe only supports a primitive version of it where the IP and gateway are not configurable.

Thanks for all the help.
------------------------------------

One other tip to contribute to this guide. I was getting an Error 31 and sometimes an error 01 on one of my NAOMI1s... I discovered that a few of the pins on the cartridge connector were bent. I was able to de-case the main board and then carefully removed the plastic housing from the connector and carefully straighten the pins out with some duck-bill pliers before re-assemlbing... Problem solved :)
 
twistedsymphony said:
though I'm wondering if it doesn't supply power via USB like the NOAMI1 does, I haven't played around with it much yet)
Click to expand...
Careful, it may look like a USB plug but they just decided on that for the physical connection, in fact it runs the JVS protocol over RS485.

http://wiki.arcadeotaku.com/w/JVS

Do not attempt to plug this into anything with a standard USB connector...
 
rtw said:
twistedsymphony said:
though I'm wondering if it doesn't supply power via USB like the NOAMI1 does, I haven't played around with it much yet)
Click to expand...
Careful, it may look like a USB plug but they just decided on that for the physical connection, in fact it runs the JVS protocol over RS485.
http://wiki.arcadeotaku.com/w/JVS

Do not attempt to plug this into anything with a standard USB connector...
Click to expand...
Oh I'm aware of that, I just said "USB" because I couldn't think of a better word to use. they do make USB adapters though: http://jvspac.kirurg.org/ ;)

Mitsurugi-w said:
You should always power your I/O using the power connectors on the I/O.
Click to expand...
for sure, I just don't have any spare cables for my bench-top setup at the moment.
 
Mitsurugi-w said:
kuze said:
Why not just power it over the jamma harness (assuming Capcom I/O)?
Click to expand...
I'm assuming it's not a JAMMA I/O.
Click to expand...
You are correct. It's a Sega JVS I/O Type 1 (837-13551-92). and I have nothing connected to it other than the RS485 cable. I have a few broken NAOMI boards that I've been repairing/burning new BIOS images for and testing on my bench so I really only care about booting up into the game to make sure everything looks ok. To be honest the only reason I even bothered connecting the I/O board is because most games will complain if you don't have it attached.
 
Got a NAOMI on the cheap ($10 locally) that powers up, both fans spin, LED's light up, but there is no video or sound. Although "c'te bastard" on my board looks like he is in good shape, I ordered his replacement anyway. Also, I have a bios coming from Mitsurugi. Will swap out the bios first to see if that is the problem, possibly saving myself the trouble of replacing "c'te bastard", sparing him for another day.


Will keep you guys posted on how this goes. Thanks again Tyler for the info.

EDIT1: No luck after swapping with Mitsurugi's multi-region bios; awaiting "c'te bastard" to arrive in the mail.
 
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