Archive for September, 2011


Stupid AP-7131 power socket

Hooked up a Motorola AP-7131 to a 300W 48V power supply today… incorrectly 🙂

PAF! Said Motorola.

Usually a bad sign.

As it turned out a fix is surprisingly painless: one 22uF 63V (or more) capacitor  (C403) and one 1 Ohm resistor (R400).

There is also plenty of space so you don’t need SMD components.

This is the cap that blew:

Sorry, no pic of the blown resistor. It’s hard to see anyway, looks almost normal.

And here is the new cap:

And the resistor (it is on the other side):


Motorola AP-7131 power and console connectors

Motorola isn’t very helpful in documenting various connectors on their business units, such as the AP-7131 wi-fi access point. So here you go…

The Power Connector

The power requirement of a AP-7131 is 48V DC, 0.7A (thus a minimum of 35W). The socket is a 4-pin male socket. It is exactly the same as the auxiliary 12V connector on an ATX board. A connector salvaged from a burnt out power supply will fit perfectly.

As it turns out the pinout of the AP-7131 power socket is exact opposite of the ATX one. Learned it the hard way (more on that later).

The pinout is:

  1. Two at the top:  GND
  2. Two at the bottom: +48Vdc

The Console Connector

The Console connector is similar to that of Cisco, with just a minor difference. Ground, Rx and Rx are the same, so a Cisco cable will work, if hardware flow control is disabled.

The pinout is:

  1. ?
  2. – not connected –
  3. Tx
  4. Gnd
  5. Gnd
  6. Rx
  7. – not connected –
  8. ?

Note: I didn’t bother figuring out the hardware flow pins.


Hello world!

Hello world! :p

Sorry, the first few posts will come slightly out of order. Have lots of pre-existing info that needed to be published for a while…