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BlueCrab

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I have a Naomi 2 board that I purchased a few weeks back along with a NetDIMM board with firmware 4.02. Earlier today, it worked just fine. However, now it is doing nothing but showing a blank screen on boot. I don't even get the NAOMI 2 logo or anything. Specifically, my monitor shows a black screen for a few seconds, then turns off as if there's no input.

Any ideas as to what could be wrong or how I could troubleshoot the issue. I've tried re-seating the board on the Naomi 2, as well as re-seating the upper board of the NetDIMM with the lower one, and haven't had any luck.
 
JSTPinout.jpg


First thing I'd do is grab a multi-meter and make sure your 3.3v is getting 3.3v. You can confirm the 5v line also but they're very picky about that 3.3v.
 
Unloaded, I'm pulling exactly 3.30v, according to my meter. With the system running, I measure 3.26v on the 3.3v pins on the filter board.

I should also mention that I have another DIMM board which boots up fine, so I'm pretty sure it's not a voltage or mainboard issue.
 
Loaded voltage is all that matters, and maybe I'm just paranoid but I'd dial that in at 3.3v on the nose. But being that close I'm not going to say that's the issue...

So booting another dimm or cart, the motherboard works fine?

If you de-case this dimm and try seating it directly to the naomi, it may get a better connection. You can also try just seating the bottom board from the dimm and see what that does. It should give you error 22.
 
remove the net-dimm, boot with nothing in the cart slot and see if you get the NAOMI logo.

if you do that means either your voltages are too low or your Net DIMM is a problem.

my 3.3 line measures 3.36V at the filterboard because that's what it needs to be to measure 3.3V inside the NetDIMM itself.

the NetDIMM is super picky about 3.3V, more so than a normal DIMM and it's very 3.3V hungry, more so than a normal DIMM, and there is a significant voltage drop between the filterboard and the NetDIMM board. So just because it works with a cart or a normal DIMM doesn't mean it's not a voltage issue.
 
Booting with nothing in the slot and booting another dimm board (also a netdimm, I should add) both work fine. It's just this one that is not working.

I tried today to boot with the dimm board out of the case, and the same thing happens -- a blank screen on boot. This is the case with or without the top board attached.

Also, after some more searching, I tried messing with the jumpers that control the DB-9 serial port on the board and attempting to get any sort of serial output during boot, but alas I got nothing. :(

I noticed that with the top board attached, when an ethernet cable is plugged in on boot, the LED closest to the ethernet jack lights up a solid green, and the one two over from that blinks green until I cut the power. I also noticed that there are two red LEDs on the bottom board that are constantly lit while it is powered, regardless of whether the top board is attached or not.

I also tried with another power supply I had laying around where the voltage was a solid 3.3v - 3.32v under load, and got no different of a response from anything I've tried.

I'm at a loss as to what it could be other than some sort of hardware failure. I'm thinking the best course of action at this point might be trying to get a replacement from the seller I bought it from (as it was purchased less than a month ago, and they offer a one month return policy)...
 
If you have two working netdimms then you could swap around those pcbs to see if you can at least identify if the top or bottom board (or both) are bad. Certainly sounds like the bottom board might have an issue. If you want to snap some photos or something we might be able to take a look, but hey if you have a return policy why not?
 
It's definitely the bottom board of the one netdimm. I've swapped out the top boards and it doesn't seem to affect the ability to boot on either of them. I'll try to snap some pictures tomorrow (I didn't see anything obviously bad on cursory inspection), but I think that unless it's something really simple, I'll see about returning it...
 
Good luck, the netdimms are picky/finicky beasts. You can also try swapping out the ram on the netdimm. But yeah, I forgot what it was that Ken told me happens to the lower netdimm board that causes it to fail.

If you can try to get a refund/replacement. You can literally spend hours troubleshooting a naomi/netdimm setup and get nowhere, when in other cases a setup just work rock solid everytime.
 
Swapping out the ram for that on the other netdimm board was actually one of the first things I tried, since I've had PC100 sticks randomly die on me before... But alas, no dice. :(
 
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