Net DIMM with a Naomi 2 -- Error 22

roothorick

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I just can't get this DIMM to work. Every time, Error 22. It was originally in a Naomi 1 (which doesn't start at all, lovely) and I'm putting it in a Naomi 2. I have a plain ol' GD-ROM DIMM that works just fine with it. I've been swapping all kinds of pieces back and forth between the two, and no luck whatsoever. I'm sure it's seated properly. The LEDs next to the ethernet jack blink twice, and then the screen comes up Error 22. DIMM test just says timeout. At one point it wouldn't let the Naomi boot at all, but I can't reproduce that now.

Help? Any ideas at all? Is there some kind of compatibility issue between Naomi 1 / Naomi 2 DIMMs? Is there a difference?
 
Does the bios support the net dimm?

Hell if I know. Which BIOS do and don't?

FWIW, it's one of those that also has the GD-ROM and serial connector. I tried setting the jumpers 2-3 2-3 1-2 and booting my GD-ROM game... curious thing. If the GD-ROM is connected it immediately goes to Error 22. If it's not connected the system just hangs on a black screen.

-E- BIOS EEPROM is labeled "EPR B 23607"
 
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There is no difference between the way a Naomi 1 and Naomi 2 interface with a NetDIMM board.

In fact, the same board can work on a Chihiro or first model of Triforce as well.

I have a DIMM board that is giving me the exact same error as yours, so I can give you a little insight as to how it happened to mine and what I have attempted to get it working again.

I was using mine for netbooting without a security PIC. Since I had grown weary of always having the connected PC running the python script, I decided to make a 0-key security PIC. Unfortunately, I have zero experience with PICs and haven't had a programming class since college ('88, and then the big language was Pascal). The net result is that I used the wrong type of PIC (a PIC16F84A-20/P instead of the correct PIC16F628A-I/P) and compiled the code with Microchip's PIC-18 compiler instead of a PIC-16 compiler.

I did successfully program the bad code on my incorrect PIC, though. When I loaded the PIC on my DIMM and powered it up it went directly to the ERROR 22. I figured that I had made a mistake somewhere and took it out but the ERROR 22 has persisted since then.

I have noticed that when I run the DIMM test in the test mode the firmware version is listed as 0.00. Is yours the same? My first thought was that the wrong PIC had erased the flash RAM BIOS, but that seemed pretty unlikely. Still, I had an extra BIOS chip from some earlier work and tried replacing it (the DIMM BIOS is on the lower board and is surface mounted, not for the feint of heart :p). It is still reading version 0.00 with that one installed.

I got some advice from a SEGA technician who said that the ERROR 22 is most common when the SMD buffer chip 74LCX16245A on the bottom of the DIMM has failed. I replaced that, but still no joy.

If there is someone out there who has a better idea than those, they might be able to get us both going.

I have since gotten the correct PIC, programmed my own 0-key and replaced the DIMM board but it was a rather expensive learning curve.

Brian.
 
I would have thought that channelmanic would have some thoughts on this. Maybe he hasn't dealt with Naomi much.

Does anyone know if the top (I/O ports / security PIC) board and bottom (DIMM slots) board are interchangeable? Can I take a NetDIMM top board and put it on a bottom board that previously had a GDROM-only top board on it? Being able to test my top board against a bottom board I know works would make things a LOT easier.

The net result is that I used the wrong type of PIC (a PIC16F84A-20/P instead of the correct PIC16F628A-I/P) and compiled the code with Microchip's PIC-18 compiler instead of a PIC-16 compiler.

The pinouts differ! I would look at anything connected directly to that socket, you may have fried something there. My DIMM had an official PIC already in it, so I'm suspecting a different issue. I think Error 22 basically means "I can tell there's a DIMM inserted, but it's not talking to me. At all."

I have noticed that when I run the DIMM test in the test mode the firmware version is listed as 0.00. Is yours the same? My first thought was that the wrong PIC had erased the flash RAM BIOS, but that seemed pretty unlikely. Still, I had an extra BIOS chip from some earlier work and tried replacing it (the DIMM BIOS is on the lower board and is surface mounted, not for the feint of heart :p). It is still reading version 0.00 with that one installed.

Even with a working DIMM, it will show 0.00 momentarily until the RAM test starts. I think 0.00 means the DIMM hasn't responded to the version check (yet).

I got some advice from a SEGA technician who said that the ERROR 22 is most common when the SMD buffer chip 74LCX16245A on the bottom of the DIMM has failed. I replaced that, but still no joy.

Huzzah, a lead! I see one of these at position IC12S on the big board on my bad DIMM. Looking at the data sheet, I'd wager a guess that testing will require a logic probe and testing in-circuit, which may not be possible due to its position :(

-E- The dead Naomi 1 that I took the Net DIMM out of has an "E" BIOS. I wonder if my Naomi 2's "B" is too old. Judging by the list on sega-naomi.com I'm way off. Hum.
 
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Big update.

I switched the jumpers on the Net DIMM top board to exactly match my working GDROM-only DIMM top board, and put it on top of the GDROM-only bottom board. I'm now getting Error 31! DIMM test succeeds, and shows version 1.02. I suspect this is my issue -- I need to update this guy. From what I'm reading, the only option is to straight up swap the EEPROM -- a SMT chip with really tiny legs :(
 
I swapped the firmware EEPROMs, and now the good one is giving me Error 22. My current theory:
  • Outside the firmware EEPROMs, both my DIMM boards and I/O shields are good
  • I have one firmware EEPROM with 1.02 on it, and one that is corrupt (interrupted update? or maybe it's just bad)

So, I need at least one, but preferably two or three, LH28F160S3T-L104 EEPROMs (or equivalent, likely any pin-compatible 16+MB TSOP56 EEPROM will do) pre-burned with Naomi DIMM firmware 3.03 or newer (4.02 would be ideal). I'll be confirming my theory by soldering my 1.02 EEPROM to the "bad" board, but let's get this ball rolling now. Anyone have a programmer that can do these bad boys?

(Holy shit, TSOP56 sockets are $20 each!)
 
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I successfully transplanted those EEPROMs, but now I'm thinking they don't store the firmware. Either that, or both my EEPROMs contain 1.02, which wouldn't make any sense (how the hell did this netdimm work at all!?)... Also, I screwed up my regular GD-ROM shield :( I'm now getting black screen of death no matter what I do with it. I guess the wrong jumper settings can do permanent damage.

Does anyone have any clue what the jumpers do? I know what Guru says about netbooting, but what he says doesn't match up with what the jumpers were on my GD-ROM shield in the first place, so obviously he doesn't know the whole story. What does each jumper do, exactly?

I'm seriously contemplating buying a netdimm I know works and experimenting with swapping parts between the two. This is driving me up the wall.

-E- Could someone with a working netdimm setup (preferably with a Naomi 2) tell me what their jumpers are set to? Especially JP4-6.
 
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Error 22 Sega DIMM Bds

Well I thought I'd jump in here. I have repaired thousands of DIMM assys and re the error 22, there are 3 reasons for this aside from the Media bd not being seated correctly. Most common cause is yes, the Fairchild 16245 buffer on "solderside" of pcb. All Fairchild buffers used on Sega platforms from Naomi thru Hikaru will fail eventually if they haven't already. Simple fix. Next would be the firmware at IC14/36 (FLASH ROM not EEROM) getting corrupted or just bad. Also simple fix. Next but much less common is the BGA at IC2 turning into a charcoal due to a shorted GDROM Drive. I have repaired around 200 of these where Drive shorted so bad, it fed back thru SCSI port and cooked this IC along with damaging FLASH and buffer. Somewhat simple fix.
 
Well I thought I'd jump in here. I have repaired thousands of DIMM assys and re the error 22, there are 3 reasons for this aside from the Media bd not being seated correctly. Most common cause is yes, the Fairchild 16245 buffer on "solderside" of pcb. All Fairchild buffers used on Sega platforms from Naomi thru Hikaru will fail eventually if they haven't already. Simple fix. Next would be the firmware at IC14/36 (FLASH ROM not EEROM) getting corrupted or just bad. Also simple fix. Next but much less common is the BGA at IC2 turning into a charcoal due to a shorted GDROM Drive. I have repaired around 200 of these where Drive shorted so bad, it fed back thru SCSI port and cooked this IC along with damaging FLASH and buffer. Somewhat simple fix.

wow... thanks for the tips, Mr Ken :)
 
Here is the jumper config on my working Netbooting DIMM :

netbootconfig.jpg


roothorick, Ken Westerman (irepairsega) at http://irepairsega.com/ can make you some replacement 4.01/2 TSOP flash bios chips. He made one for me and I was able to update a netDIMM from 2.06. He was reasonably priced as well.

Brian.
 
Thanks dbstallman! I set my jumpers that way and I'm getting... Error 31.

I decided, what the hell, I'm gonna plug a computer into it and try to interface with it. Got some promising results. I set it for 10.0.0.1/255.255.255.252 and put my laptop to 10.0.0.2/255.255.255.252. Guess what? I can ping it! So I went for broke and tried triforcetools.py. It went "Connecting.... ok!" and hung. So, the NetDIMM is working well enough that I can connect to it, but it doesn't respond to commands.

I'd put good money on that DIMM firmware now. This NetDIMM was riding atop a linking plate in a Naomi 1, so my theory is it used the ethernet or serial for linking, loading the game from GD-ROM. I'm guessing that 1.02 was more than sufficient for this, so Sega just stuck a universal shield on a surplus DIMM board that was originally made for an early GD-ROM DIMM. When the board quit (that Naomi 1 arrived quite dead), the op shelved it, and the GD-ROM and cable was taken to resurrect a different machine at some point.
 
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Son. Of. A. Bitch. I just can't win.

I got the 4.02 chips a long time ago and got sidetracked and distracted and clean forgot until now. Now I took a look at them, and they're a different size. The flash ICs that I'm assuming are 1.02 are Sharp ICs that go in the IC14 position, and the new ones are smaller and fit in the IC36 position. So, that's where I put them. I don't know if that's causing my problems or what...

...but now with that DIMM in I can't get anything besides a black screen. If I start the machine with nothing in the cart slot I get the bog standard Error 01 and can run all the tests and everything. With the NetDIMM in.... absofuck nothing. I've played with jumpers, reseated it about six times, just nothing.

I'm really getting tired of this thing.
 
Old thread, but, since someone bumped it...

Error 31 is a generic netboot failure. Error 22 means bad connection between the DIMM and the board.

For 22, you want to take a look at the daughterboard on the DIMM; verify the connections are nice and tight, and clean all of the connectors. Then, do the same on the mainboard. Try again. If it continues to fail, you have a bad DIMM.

Error 31 indicates a configuration error of some kind related to the netboot setup, it could be anything. Usually, though, it means that there is no connection between the board and the server.

I never saw any mention regarding the mainboard BIOS version or the DIMM BIOS version. The mainboard should be 23605B or newer, and the DIMM must be 3.17 or newer. If not, netboot is not possible.
 
... For 22, you want to take a look at the daughterboard on the DIMM; verify the connections are nice and tight, and clean all of the connectors. Then, do the same on the mainboard. Try again. If it continues to fail, you have a bad DIMM. ....

If the Dimm board is found to be bad (Battery, Ram, Daughter Board all work with a known good Net/Dimm board; however, all these post Error 22 on the the bad Net/Dimm board); then, are

there any other parts to look at on the bad Dimm board besides the 74LCX16245MTD buffer chip on the bottom of the board, the MX29LV160DTTI Bios chip on the top of the board, and the

BGA chip right next to the Bios chip?
 
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Yup.

Not sure of any forum members that do BGA rework. I don't.
 
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