How can i know my Famicom is working?

[omri617]

Hi friends
Bought a used Famicom from E-bay and the seller noted that it hasn't been tested
connected it to my LCD and nothing appears on the screen
is there anyway to know for sure if it's working or broken?
thanks

[jpx72]

Hmm is there any change on the TV when you turn the Famicon on?
If not, it can be damaged. Do you have any voltmeter? You can check the voltage on the cartridge connector, there should be +5V DC.
If you cannot read the voltage there, the fuse can be blown. A repair of that is relatively easy.

cartridge connector pinout: http://benheck.com/Downloads/NES_Famicom_Pinouts.pdf

[Lum]

You might need to try a weird TV channel, or maybe that LCD isn't compatible with the kind of RF an early Famicom expects.

[Drakon]

Usually I just wire up a rca jack to the audio out pin on the cartridge connector (pin 46 I believe) and ground.  Then if I get audio that means everything is most likely working.  If you want to take it a step further build a composite video amp and wire up the ppu as well.

[omri617]

help please
Post Merge: February 08, 2012, 03:04:07 pm
where is the Fuse located ?

[petik1]

Fuse... I think they mean voltage regulator.

1) Make sure you're using the correct AC adapter. The wrong one will harm your Fami.
2) Make sure you're on Channel 95 or 96 if you're using RF.
3) Do what Drakon said.

[jpx72]

Fuse... I think they mean voltage regulator.

Eh not quite, in newer revisions there is a small black prismatic component - the fuse - in the RF section (near the power adapter connector):
http://www.famicomworld.com/forum/index.php?topic=3924.msg78848#msg78848

[omri617]

about this black fuse , i found it and i checked with voltmeter and it shows 8.3 (DC , right?)
checked the voltage in my adapter and it shows 8.6/8.7 volt
is it suitable for the famicom is it enough?

[jpx72]

Fuse doesn't work that way. You must check if the ends of the fuse are connected together. If not, the fuse is blown. Use ohm-meter.

The voltage on your adapter is okay for your Famicom. Just mind the polarity = center of the plug must be negative. If you put it wrong, you will blow the fuse.

[omri617]

ohm meter is : - (minus ) 7.30 when the red stick voltmeter is set on the end of the fuse that is close to the adapter input
is it ok?
or even possible?
checked the fuse it looks ok and both ends connected

Post Merge: February 09, 2012, 04:57:07 am

Hmm is there any change on the TV when you turn the Famicon on?
If not, it can be damaged. Do you have any voltmeter? You can check the voltage on the cartridge connector, there should be +5V DC.
If you cannot read the voltage there, the fuse can be blown. A repair of that is relatively easy.

cartridge connector pinout: http://benheck.com/Downloads/NES_Famicom_Pinouts.pdf

by the way checked the pins , there is no voltage there

[jpx72]

You have to put your multimeter on resistance measuring (Ohm) and put both probes on fuse's ends. When blown, a fuse is an open circuit and will have infinite resistance. Before it blows, it has very close to zero resistance.
The adapter doesn't have to be plugged in when measuring the fuse.

[omri617]

i did exactly as described :
the multimeter shows me nothing , it doesn't change : stays on 1.      on the screen
measured the capacitor next to the fuse and it showed me 0.48
what is the next thing?
thanks a lot really appreciate your help

[jpx72]

If the multimeter doesn't change, it means the fuse is dead. You can desolder it and solder a wire instead (Fuse is basicaly only a wire too, but it's thin enough to burn when the voltage/current is too high).
If you want, you can buy another fuse and put it there for continuous protection.

Do you know why the fuse died? Do you have the correct polarity (plus/minus) on your adapter???
You can check it with multimeter - set it on Voltage measuring, put the minus-probe inside of the power adapter plug and the plus-probe on its cover. When you measure + (positive) voltage (for example +8.3 DC), you have the adapter set right. If there is a - (minus), you have it wrong.

[omri617]

did it , and it shows me +8.7
the black probe (COM) inside the plug and the red outside
i prefer to buy a fuse to prevent frying of the whole famicom , which fuse i need exactly? what is the spec. of it?
thanks again

[jpx72]

Buy any 1.5A fuse, you'll be fine.  Buy one that is easy to solder. The one in Famicom is called a "Pico-fuse".
The same as in SNES, here's even a tutorial video for it: http://www.youtube.com/watch?v=7wkM86SK6ec
Also here: http://www.mmmonkey.co.uk/console/nintendo/snes-fuse.htm

It may happen that when you replace the fuse and start your Famicom, the new fuse will die too. In that case, something else is damaged. Most probably the 7805 voltage regulator. It's cheap and relatively easy to replace too, so don't worry.