Hi-Def NES Reversed Polarity V/GND

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MNiceGuy
Posts: 12
Joined: Sun Sep 10, 2017 6:21 pm

Hi-Def NES Reversed Polarity V/GND

Post by MNiceGuy »

I just finished up another Hi-Def NES but when I went to test it, nothing happened when I turned the power switch on. No image on the screen, no light on the Hi-Def board, nothing.

On inspection I realized I had the V and GND wires (attaching to where the 7805 was) backwards. I corrected the issue and now everything seems to be working great.

The question: Since I would like to sell this particular NES and have confidence in doing so, could I have damaged something by attempting to power the system in that state? There was no smoke, no pops, or any other obvious signs something was damaged. Does the Hi-Def board have protection against such a situation? As I mentioned, the system is working great and seems to have remained stable after a 4 hour test.
hernan43
Posts: 1
Joined: Mon Jun 19, 2017 8:58 pm

Re: Hi-Def NES Reversed Polarity V/GND

Post by hernan43 »

I would be surprised if kevtris didn't put a protection diode on it. You should shoot a tweet at @gametechus I'm sure he knows.
MNiceGuy
Posts: 12
Joined: Sun Sep 10, 2017 6:21 pm

Re: Hi-Def NES Reversed Polarity V/GND

Post by MNiceGuy »

I reached out to Jason. He is not of the belief that there is any reverse polarity protection on the board but he did say such a circumstance likely did no harm.

There were no signs of physical damage on either the Hi Def or NES boards. All the regulators were either spot on or VERY close to it. All the capacitors had ESR well within the acceptable ranges. To be extra sure I ran the system for a couple days and everything seems fine.

I think I dodged a bullet on this one.
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