Attention Motorola Surfboard SB5120 owners! I (no longer) need you to look at your power adapter.

[Jeff7]

I recently bought this modem used on the forums. The adapter that was included is marked "9VAC" while the modem calls for 12VDC. The seller says he used this adapter with no problems, but I'm not about to plug AC power into something that needs DC.


Now the problem: the modem isn't marked as to which is positive and which is negative. So I need someone to have a look at their modem's power adapter and tell me the polarity.

Thanks.



Update: Got it. Netsysadmin, after checking the pics of your modem, I figured I'd test out something with that polarity. I found a 9VDC adapter, and it powered up the modem. I've now got a 12VDC 1.0A adapter on the way. So, thank you.


FYI
Motorola SB5120's power stats:
- 12 VDC, 0.75A input
- 5.5mm outer, 2.5mm inner diameters
- center positive


Too bad Motorola's documentation doesn't include that information anywhere.

 

[netsysadmin]

Well I have a Motorola SB5101 which is not your model exactly, but I though it may help? The spec's are below.

LiteOn
12v DC 750mA
Center is positive and the outer ring is negative

John

 

[Jeff7]

Well that's the same current draw as mine. I'll keep it in mind, and thank you for checking.
The two units look almost the same, too; they likely used the same basic design. If I find a 12V adapter that actually fits, I'll give it a shot.