screen dims when power applied

I have a c530 and it does not dim for me..

Not sure what your settings are but could it be that? i am sure someone here will give you a proper answer in a very short time..

Good luck!

Are you using Garmin power adapters?

Does your unit have a brightness setting?

I rarely run my 660 on battery power for very long. Normally in the car, I have it plugged into the cigarette adapter.

But, I see the same thing you described. I powered mine up on battery power. Then, I connected the Garmin supplied a/c wall charger that plugs into the USB connector and the brightness dropped slightly. I then unplugged the a/c adapter and the brightness increased slightly.

I looked under the settings, just to be sure, and found no brightness adjustment. Under Display, the only adjustment is the Backlight Timeout, which is not the same thing.

So what we are seeing appears to be normal operation. I would assume that Garmin had a reason for designing it this way, but I don't know what the reason would be.

as MM stated, make sure you are using a Garmin adapter. it sounds like it's not getting the correct juice when you plug it in.

LCD screens take a lot of power to run ... a cell phone charger or the like may not be delivering enough.

I noticed the same thing on my 760. Just change the brightness setting while it is docked. Even though it is the exact same setting screen, the settings are different between docked and undocked. I assume they did this so you could set it bright while on DC power and dim while undocked to save power.

Brightness settings are on Page 4 of the manual http://www8.garmin.com/manuals/nuvi660_ownersmanual.pdf

Sounds like the battery may be going. If the battery is partially shorted, it could be drawing too much power when you attempt to charge it, thus the dim screen. The fact that the battery only lasts an hour, indicates it's not quite right.

My 680 does the same thing. My battery lasts for hours (haven't really timed it, but I've been running on battery with the MSN cord connected to watch the MSN packets download, so I know it is good for more than an hour).

Anyhow, when I plug in the Garmin AC charger, the screen dims. I can't remember if connecting to the PC does the same thing or not.

Q

Same here!
My less than 2 month old 660 does the same thing.
This cannot be attributed to the battery.

I noticed this when I had to use my 350's car adapter to power it when I had to send the 660's GTM20 back due to problems with it.
I plugged the 350's adapter into the USB port for power. It dimmed. I plugged it into its garmin supplied 'wall wart', it dimmed.
I can't tell ya why... But I can tell ya that I've seen this as well...
(BTW.. I'm still waiting on a replacement 660 cuz the speaker blew a few weeks ago..)

This answer is dead-on! What I was doing was using the ac adapter into the usb port, with a power inverter from the cigarette lighter. That's when it dimmed.....I finally plugged it in with the traffic receiver which goes into the back of the suction cup mount. Now, not only does the screen NOT dim, but the backlight NEVER times out!! LOL From one extreme to the other. But the latter is better, no worries about the battery dying and it's bright enough to see. At night I turn the contrast down...

Dear John,

When I have my 650 plugged into the car lighter, the screen does not dim even when I have it set to dim after fifteen seconds. Therefore, if it is night and the light from the box seems intrusive, I unplug the unit from the lighter and let it run on battery.

david

johnnatash4.

As I understand it, the nuvi keeps two brightness intensity settings, one for when it is operating on battery, and one for external power.

In your case, it seems that the brightness for external power is set lower than the brightness for battery, so if you increase brightness while using external power and turn off, it should go back to that brightness intensity next time it is on external power.

Could you try that and confirm back?

Ny Nuvi 250, does the same thing, WITH the supplied Garmin Adapter. I don't think it's an adapter problem.