Dead A/V Famicom? Some Tshooting, and Pics Inside.

[shoggoth80]

OK guys,
I got this in the mail today. I've already contacted the seller, and there's an agreement to replace any dead components up to, and including the system deck itself if that is what is bad. So, there is that.
As the title says, it doesn't work. No screen flicker when the switch is thrown, nothing. I swapped out the AV cables for a known set of good ones. No change.

I just tested the PSU. It reads 16v DC without a load on it. I have heard that the wall warts will produce greater than their printed voltage without a load. Is this true? It's a Genuine Nintendo Famicom transformer. 100v AC 50/60Hz to 10v DC 850mA. Now, I'm not positive that it is one for the AV unit, as I don't know if it was changed. I do know that it is Nintendo branded, and a Famicom PSU. I don't think Nintendo made any changes to the power requirements. It was also what was sent with the system. Do I have a faulty PSU, or does that voltage rating sound about correct?

The only other thing at this point would be a dead console. The insides are pretty clean. I had the board removed from the casing earlier. It doesn't appear to have any leaking caps, obviously broken joints, or pins. The only thing I could spot was some discoloration on the bottom side of the board where the power port is. I am not experienced enough to tell if this is a spot that was overheated, or if it is just flux from the solder.

Anyone lend their experience? Not only do I want to have a working AV Famicom in my collection, I want to make sure that the seller and I take the proper corrective actions to make the deal right.

[Great Hierophant]

The AC adapter that came with the Famicom was intended to be used with the AV Famicom.  The AV Famicom does not come with an AC adapter, the idea was that you would use the AV Famicom to replace the original Famicom with its crappy RF output.  The ratings are correct. 

The extra voltage without a load seems reasonable : https://www.sparkfun.com/tutorials/103

That discoloration is normal flux residue. 

With your multimeter, you should start by checking the voltages inside with the power supply turned on.  First, check the power socket and the voltage regulator, then the voltage regulator and the power and ground planes. 

[shoggoth80]

Ok. Thanks for the information regarding the brick. I didn't know the AV unit was sold as an upgrade type deal. Interesting.

Sad news. I tried a known set of good cables, and a known good power supply (with the same power ratings, and polarity), and nothing.
I plugged in my Micro Genius clone, and game fired right up. Bummer. Dead console.

Message has been sent to the seller, and we'll get it hammered out.

[2A03]

Might just be a dead voltage regulator, have you tried checking the output voltage on the 7805?

[shoggoth80]

Nope. I need to do some googling on that. The seller is sending out a replacement for the dead one, so it's kind of moot.