Original Post

Had my Flashboy in the Headunit and hooked up the USB cable without taking the cart out and it powered the system up…Is this normal?Might I have damaged the Virtual Boy?Freaked me out a little bit.

6 Replies

That’s not abnormal… I’ve never done it w/ the Flashboy, but I’ve connected the VB 5V rail directly to a regulated 5V for power and it works just fine, as well as powering the VB by USB (which is basically what you did). I assume there’s no isolation on the Flashboy between the USB 5V and the VB 5V, so that makes sense that it’d do that.

Of course you don’t have a power switch that way, and I wouldn’t recommend it, since the VB draws quite a bit of current (~350mA IIRC) at 5V, which is sorta less than the USB spec allows, depending whether the Flashboy negotiated for higher power (and before it actually drew more). I doubt you’d damage the USB port, but you can’t really guarantee that, and I’m not sure what the inrush current is when it powers up.

You could also possibly do harm by turning the VB on w/ an AC adapter/batteries and have the VB send power back the USB cable.

So anyway… you’re probably fine, and if everything seems to be working, I wouldn’t worry about it, but I wouldn’t recommend doing it again.

DogP

But if you run it from a USB-connector wall-adapter that has enough power?

Take off the power adapter or battery pack and run the VB from a USB-power-source (not your computer) – an extra feature there. Slap on a 5m USB-extension cord and you have enough length as well…

If you have a FlashBoy it’s a cheaper solution than running from batteries or buying an official AC/DC-adapter.

I don’t see any reason why that wouldn’t work. Most adapters are rated for 500mA ish current, which is a little low, but should be fine. The only downside would be no power switch, so you would have to unplug the cable to power down.

The obvious thing would be to create a USB cable with a decent enough length and a built-in power switch. 🙂

I really want to try this on my VB but i don’t want to be the first one too post “Hey don’t try it, it will burn up you’re flash cart and system!” Lol 😯

Deadly-D wrote:
I really want to try this on my VB but i don’t want to be the first one too post “Hey don’t try it, it will burn up you’re flash cart and system!” Lol 😯

We just need Richard (or someone else who has access to the board artwork… KR155E? DogP?) to do a thermal simulation on the power trace(s) running from the USB connector to the VB cart edge to see how much current it/they can handle. Or, you could just measure the peak current draw of the cart and VB separately, and use an appropriate fuse on the USB cable.

Of course, you’re also up against the USB current limit, unless you make a custom cable and use a “wall charger” like UncleBob and e5frog suggest.

 

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