Sega Naomi Net DIMM Issue - Firmware 0.00

[paulie]

In a nutshell the netdimm throws up an error 22 and the firmware is showing as 0.00

But if you can be bothered to waste 5 mins of your life then here's the long version...

I'm going to netboot mostly for convenience as I already own pretty much all the Naomi and Atomiswave games I want to play.

Anyway I put up a wanted ad here and bought a net dimm which should arrive shortly.

Soon after that I got a pm from another member and I thought having a spare wouldn't hurt. He said he had a couple, which he bought as workers but couldn't test them. He's only 10 mins down the road from me and very kindly offered to bring them round and we could test them together. We tried a bunch of things but just kept getting error 22, anyway he's really cool and said that if I couldn't get the one he left with me working then he'd refund me, he's a really good bloke so no worries there and lets be honest you can't say any fairer than that. I thought it'd be something obvious and my initial thought was swapping the bios to a newer version on my mobo. Now a new multi bios has arrived I can sadly say that wasn't the issue

Done loads of googling, asking around and tried absolutely everything that I've read but it still throws up error 22, but after a bit more googling and having re-checked the firmware, I'm now 99% sure that its the firmware that is the issue. We did check the firmware the other day which showed as 0.00 but kinda thought if the bios is too old then maybe it's just not recognising the firmware.

I can confirm that everything other than the netdimm is 100% tested and 100% working this includes: voltages, cab, psu, all cabling, Naomi 2 motherboard, Bios has now been changed to a multi which works with every cart and GD-ROM I've thrown at it, the GD-ROM drive and SCSI cable are also good. Then when I swap out the vanilla dimm and plug in the netdim in and yep the jumpers on the netdimm are set for GD-ROM...Error 22

From my searching I've read and tried all of the following...

re-seating the netdmm, pushing the netdimm down firmly, laying it flat, removing the battery, checking the connections between top and bottom boards, removing and cleaning the pins on the memory with isoprop, using the original screws to screw the netdimm down on the mobo, basically all sorts of things.

I can only find two threads on the net that reference 0.00 firmware but with no definitive solution only a suggestion to de-solder an IC, then burn the firmware to said IC and solder it back, which to be frank is beyond my skills.

Anyone come across this before? and did you fix it?

Cheers

Paul

 

[jonhughes]

Does it give error 22 with nothing at all plugged into the Naomi?

 

[Monstermug]

I had an error 22 when I removed the flash IC next to the sega communication ic and replaced it with a blank one. Basically could mean that either sega communication IC, Fujitsu flash ic is faulty, or perhaps a bad connector/dry solder joint in between. Maybe just check for lifted pins on this ic. Or even better ensure that the PIC IC is working properly.

[sub][/sub][sup][/sup]

Monstermug2020-01-22 21:36:08

 

[paulie]

Firstly, thank you both for taking the time to read and reply, it's appreciated

Does it give error 22 with nothing at all plugged into the Naomi?

When nothing at all is connected to my Naomi 2 mobo (ie no game cart/no dimm/ no netdimm/ no GD-ROM) it shows Error 01




When I connect a cart or a regular dimm/ GD-ROM it plays first time no issues whatsoever




When I connect the netdimm it shows Error 22




When I connect the netdimm along with the GD-ROM and game security chip it still shows Error 22

I had an error 22 when I removed the flash IC next to the sega communication ic and replaced it with a blank one. Basically could mean that either sega communication IC, Fujitsu flash ic is faulty, or perhaps a bad connector/dry solder joint in between. Maybe just check for lifted pins on this ic. Or even better ensure that the PIC IC is working properly.

[sub][/sub][sup][/sup]

Thanks mate, I'll check those now.

 

[Monstermug]

If you are lucky the fujitsu ic in picture may just need a reflow or maybe the pins connector is bent somewhere? Worst case senario is sega chip next to it is faulty.

Error 22 means that there is a communication error between the mainboard and the net dim.

 

[paulie]

Thanks mate.

Unfortunately I couldn't spot anything from a visual inspection and as my mate said he'd refund me if I couldn't get it working I didn't want to try and reflow the solder and cause an further damage due to my cackhandedness as I've never tried to work on anything so small but thought I'd just update just in case this thread is of help to anyone else.

My mate and fellow Vaccer came back today and he had another Netdimm which was working so he swapped it for the bad one which was really awesome of him

also got one in the mail today so got a working spare too.

 

[Ace`]

It's usually a buffer that goes on these, I can't remember the part number off the top of my head. Non net dimms used to be so cheap it was be easier to just swap the bottom pcbs.

 

[Monstermug]

Thanks mate.

Unfortunately I couldn't spot anything from a visual inspection and as my mate said he'd refund me if I couldn't get it working I didn't want to try and reflow the solder and cause an further damage due to my cackhandedness as I've never tried to work on anything so small but thought I'd just update just in case this thread is of help to anyone else.

My mate and fellow Vaccer came back today and he had another Netdimm which was working so he swapped it for the bad one which was really awesome of him

also got one in the mail today so got a working spare too.

Best to use proper tools for surface mounts. A bad pic can also cause error 22 it seems. From experience, it seems the sega communication chip interface with the pic and the flash ic to make things work. Yes, faulty buffer chip 74LCX16245A on solder side of pcb can also cause error 22. Lastly, as I have experienced before a faulty firmware on the 16245 flash would also cause this fault. Sometimes people brick them by updating them wrongly. Obviously, you will want to eliminate other causes such as bad connectors etc and start with the easiest first.

As the net dimm is showing filmware 0.00 I would most probably look at the 16245 flash ic.

Having said all that i don't consider myself an expert or anything. It's what I have learned repairing my own net dimm board recently. I've also got the memory of a goldfish so this might help job my memory in the future.

Monstermug2020-01-25 22:13:57