NES doesnt power on when cart is inserted???

I wonder if anyone has come across this issue before.

Back about 2 weeks ago i tried the boiling the NES cart connector trick to get the 72 pin connector to work again on about 4 NES NTSC Front loading consoles, on the whole it seems to be successful (some had to be just inserted but not pushed down for them to work). Anyway was playing about with them today and noticed that when i powered one of them up the power led came on and then when out, i checked the fuse and it was fine tried the PSU in one for the other NES's and it powered up fine, plugged in the same cart and the samething happened, led power light came on then went straight out, tried the same steps on a 3rd NES and the exact same thing happen.

I stumbled upon that if i inserted the cart without pushing it down in the locked position then the NES powered up fine, as soon as i pushed the cart down i lost all power, this is the same for all 3 NES consoles!.

Any ideas on what the hell is happening here, is it the 72 connectors gone bad (all 3 of them??) or could it be the game cart causing the issue?

 

Ok slight update on this, one of my NES has now appear to have been killed due to what would appear to be a fault cart!!!!

The cart in question is Super Spike Volleyball (PAL), upon hooked the video and audio connections up to the NES i noticed when this cart was insert and the NES was turned on i would go no display and just a humming sound coming from the speakers. At the time i had the lid, shielding and cart loader tray removed from the NES and just had the cart inserted in to game connector. I noticed if i raised or lowered the cart slightly the humming changed in pitch, strange i though just as i began to smell burning and then noticed smoke coming from what i believe was the large Cap on the PSU section of the NES (top right on the pcb where you plug the phono and power connections in!!) so i quickly unplugged the NES

I think the NES is now dead as every time i power the system on the cap begins to smoke.....thats if it is the cap smoking and not some other component i cant see due to the shielding around the PSU unit section. Would replacing this Cap fix the issue??, if so where can i source one from (UK ideally)

I guess the more important question here is how on earth can a cart cause this issuse???

 

Appears the large cap was fine cant see any physical damage to it or any burning around the solder points on the pcb of the NES. Looks like the culprit is these diodes?, D1 and D4 look like 2 burnt...........



Taking them out and i pulled one of them slightly and it snapped in half!, didnt apply much force at all.....



You can see the burn mark on the pcb, guess that was the bad one then....



Would could have caused this to happen?

What type of diodes are these are they a special type havent seen anything like these type before

 

Double Post

 

Crickey! That's a bit rough! Check that cart out as not to do the same.

They look like zener diodes of some sort. You could check one of the remaining good ones for micro mini writing on the side. Might be an idea to replace the cap to be safe.

 

Apparently, i want at least 1.3A and 15v diodes, i seem to be able to find a lot that are 1A and go all the way up to 1000v but none around the 1.3A range. The 1n5400 series are 3A rated......

http://www.vishay.com/docs/88516/1n5400.pdf

over kill i know but guess it wont hurt at the end of the day.


So i opened up the cart and notice the burn mark on the inside of the case and the browned legs of the 1MC3B chip.....



not sure why that happened!?

 

Did the power LED continually blink on and off? If that's the case, you need to bypass the 10NES chip.

 

you mention trying the cart without the cart tray. Is it possible you inserted it reversed?
Anyway, I suspect the cart power rail is shorted. Which is not a good thing for your NES.

 

The clear-looking diode is often geranium diode. They have lower forward voltage than more common silicon diode. Looking at the board one can see there's 4 diodes so I am quite positive it's arraigned as a full rectifier bridge which turns incoming AC power from NES 9v transformer into DC, and that large cap you removed is likely used to filter the ripple at the end of the bridge.

Under normal circumstances, a diode don't just die by itself. There had to have been a short or something to burn a diode up. If you can remove the shield from the bottom, I'd check at spots with ohm meter to look for low reading or zero ohm from the DC in jack to the 7805 regulator. It could be a loose screw somewhere (in power board or main board) you lost and forgot that caused the short or something.

Looking at the cart pinout, I don't think inserting it in backward could cause a burned diode.

 

Maybe the cartridge or the connector had something in it or maybe pins in the connector were bent and caused a short between +5v and Ground. Maybe you should use a tool to check that, though I'm not sure if doing something like that wouldn't have fried the important components or not. If the CPU or PPU are damaged then it's basically a dead system.

 

I think this happened because the OP boiled his pin connector. It didn't dry well enough leading to a short. Lesson? Don't boil your cart connector. I personally use Deoxit.

 

I do agree, I don't think you should be boiling your connector. You can improve a connector's conductivity without submerging it in boiling water. Not sure if that is what caused his problems though. He said they worked initially.

The boiling of the connectors could have comprised the plastic or metal though. You really aren't supposed to heat them up to such extreme temperatures. We don't know exactly how hot the water was or how long the parts were in this water. We don't know how they were cooled off afterward either.

One thing that is important is it's a bad sign if the game only works if you don't push the cartridge down. It was designed the other way, it should only work with the cartridge pushed down. In general I find alot of people blame the system for why they have problems with games not working or glitching. Often though if you clean the games it will work just fine. Most people never bother to clean the games.

 

I don't think the connector boiling has anything to do with it, at least not directly. I have boiled connectors often.
I usually spin them in a pillow case after the boiling which removes most of the water and what little remains evaporates du to heat in a few minutes.
I think the cart was defective.

 

Well unless the pin connectors take over a week to dry then no this wasnt the cause

 

I'll tell you what happened here:

That MMC3 chip shorted internally. That caused an overcurrent which exploded the rectifier diode at the metal box.

I don't think that has anything to do with boiling the cartridge connector because the NES don't have any high voltages on the cartridge connector.

That MMC3 chip was shot and when you connected the cartridge it caused a short circuit which damaged the NES power supply circuitry.

Now, after that abuse I would replace the four diodes and the 7805 chip if I were you.

 

What do you suggest the "rusting" on the MMC3B legs are?

 

It did CATCH fire, didn't you notice ?

 

Ok i replaced the diodes and the NES seems to power up fine, no signs of smoke or burning smell. But what i have noticed is that the 2 games i tried dont appear to display correctly the screen is all garbled.

This is Silent Service....



and the about 2 seconds later changes to.....



And this the my NES EverDrive flash cart...



Does this look to anyone that the PPU chip is faulty, as i got a replacement PUU from here.....

http://www.arcadecomponents.com/catalog/item/3054735/2583135.htm

and i get the same results after replacing the PPU chip, any ideas?

 

I agree with this, water isn't actually very good for cleaning metal with, in fact it encourages oxidisation. Although I wouldn't recommend people use boiling isopropylalcohol!

 

Sprites look fine. Look that Konami logo. Also the tiles don't look damaged. It is possible that the SRAM chip near the PPU is blown. Probably when the MMC3 chip exploded some overcurrent went through the PPU chip BUS and that fried the video ram (which stores the tiles name tables).