Hi everyone,
Please take a minute to take the cartridge off the base and inspect your system!
In particular you want to look at the memory retaining capacitor on the board. It's stuck between the IC29 RAM chip, the BIOS, the lithium battery, and a small 8 pin serial EEPROM.
I've found 2 different types of .1f memory retaining capacitor on the boards. If yours has the BLUE capacitor you need to inspect it for leaking. Look for oily residue on the board and discoloration on the cap's exposed metal pieces. Also look for crusty corrosion on the solder joints on the transistors and chips (especially the RAM chip, IC29) surrounding the capacitor.
If you see any of this you need to remove that #$&*^# capacitor IMMEDIATELY and clean up the mess on the board.
IT WILL EAT TRACES IF YOU DON'T CLEAN IT UP.
The other system I have here has a brown cap. It doesn't appear to be leaking but in any case you'll still want to check your system if you have the brown cap instead of the blue.
I fixed the system board. One of the traces on that 8 pin EEPROM was damaged by the electrolyte. One quick patched trace and it was back up and running. (Well, after replacing IC29, but that's a different story)
Raymond
Check your NAOMI system!
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OldFoo
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OldFoo
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OldFoo
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OldFoo
channelmaniac wrote:Post a close up pic of that board around the leaky cap.
The NAOMI 1 has the BIOS ROM, IC29, and the serial EEPROM around it. Any of those can suffer trace damage. Luckily it's not too hard to patch a bad trace to revive the game.
RJ
It's practically the same on the Naomi 2. I've replaced the capacitor on the N2 and N1 motherboards this afternoon, replaced the batteries and still get nothing showing on the screen.
I have 5 motherboards. 2 x Naomi 1 units work on the Universal cabinet I own. 3 of them don't. I think 1 of the boards has a serious issue, therefore I was really only expecting one of the N1 motherboards to potentially operate and as the N2 cap was badly corroded I was hoping that was the problem.
If anyone is in any doubt, in all 3 instances the cap leaking was far worse underneath the cap (the PCB side, which is clearly hidden whilst it is soldered to the main board). Worth checking I would say!
I'm damned if I know why these units fail to work. The seller(s) were sure they all functioned properly. Can't keep buying faulty Naomi units and nobody seems to know of anyone in the UK that repairs these motherboards.
Why would I manage to get 2 x motherboards to function using the Universal and not the others? It surely points at the motherboards being faulty than something wrong with the Universal set up. The screen doesn't kick in - no audio output. Same issue on ALL three of the motherboards.
A depressing body count of Naomi corpses. :smt009
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OldFoo
Is there an 8 pin serial EEPROM in a socket next to the cap on the NAOMI 2?
On the NAOMI 1 that chip holds the run-time code for the FPGA chip. If the FPGA chip can't read that EEPROM then the system will be nothing more than a fancy white brick. That's what happened to one of the units I have here to repair. It's now working and I'm waiting on an order of new caps to come in to finish it up. (I ordered 25 of 'em to get the price break)
You'll have to check continuity on the traces around the cap and patch any bad ones to revive the system. If you use a Jewelers' Loupe you can look real close at the traces and the plate thrus to see the corrosion. A multimeter with continuity beep will help you find the corroded traces and platethrus that need fixing.
RJ
On the NAOMI 1 that chip holds the run-time code for the FPGA chip. If the FPGA chip can't read that EEPROM then the system will be nothing more than a fancy white brick. That's what happened to one of the units I have here to repair. It's now working and I'm waiting on an order of new caps to come in to finish it up. (I ordered 25 of 'em to get the price break)
You'll have to check continuity on the traces around the cap and patch any bad ones to revive the system. If you use a Jewelers' Loupe you can look real close at the traces and the plate thrus to see the corrosion. A multimeter with continuity beep will help you find the corroded traces and platethrus that need fixing.
RJ
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OldFoo
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OldFoo
channelmaniac wrote:Is there an 8 pin serial EEPROM in a socket next to the cap on the NAOMI 2?
On the NAOMI 1 that chip holds the run-time code for the FPGA chip. If the FPGA chip can't read that EEPROM then the system will be nothing more than a fancy white brick. That's what happened to one of the units I have here to repair. It's now working and I'm waiting on an order of new caps to come in to finish it up. (I ordered 25 of 'em to get the price break)
You'll have to check continuity on the traces around the cap and patch any bad ones to revive the system. If you use a Jewelers' Loupe you can look real close at the traces and the plate thrus to see the corrosion. A multimeter with continuity beep will help you find the corroded traces and platethrus that need fixing.
RJ
Yeah, the 8 pin chip is located in roughly the same area on the Naomi 2 motherboard. I couldn't get caps that fitted exactly so I had to solder 2 thin wires between the + and - terminals on the cap and run the wires back to the motherboard. A distance of about 3 inches or so, just to ensure that these caps don't interfere with the games cart when it is pushed into place.
I'd like the exact model number too as it might also be that the additional wire causes too much of a drop for them to function properly.
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OldFoo
Dave_K. wrote:Checked all 4 of my mobos, and I have either black or blue color caps. One of the black ones looks corroded near the bottom, but no leaking. The blue one looks great.
Do you have a part number and catalog you are ordering these from?
Looking corroded near the bottom IS the result of it leaking. That crap is nasty and will corrode things like crazy.
I can't find the paperwork from when I ordered the caps. They should be here today. I'll post the part # off the invoice when they arrive.