Broken ?.... maybe it's the connection to the hot shoe. (ie a connection in the base of the unit). You said it test fires with the button so the flash head itself is OK.
Has it ever worked on camera? at all ?
There's 5 contacts including the ground. The big centre one is the one that fires the flash. I don't know how its effected if the other pins arent contacting. Maybe it loses the P-TTL function or it wont fire in P-TTL but works in manual, maybe not at all. You can use the AF360 on older cameras with only the centre terminal for triggering and the ground(shoe).
Flash Systems Evolution, Features and Operation
If you use it wireless mode then, it doesn't matter if the contacts are working properly. Does it work in wireless mode?
I guess you probably doing everything right, you've read all of the manuals, so I might not be saying anything you dont already know, but just to double check anyway......
- built in flash set to wireles mode
- AF360 set to wireless mode (on/off slider switch to the middle, wireless)
- AF360 set to slave on the M/C/S sliding switch.
- the channel has to be the same on the flash and the camera obviously. When you put the camera's flash mode into W the current channel is shown in the viewfinder for 10 seconds. (K-x manual page 165)
- The AF360 has to be set to the same channel. You can set the channel in the flash's menus.
- Putting the AF360 in the hotshoe in wireless mode and half-press the shutting should match the camera channel to the flash setting. If it doesnt then the communication thru the pin isnt working.
- Slave made set to Slave 1 . this is a more obscure setting (see AF360 manual page 49). It has to be set to Slave 1.
If it is set to Slave 2 then P-TTL wont work, the flash will go of on the pre flash
before the exposure.
I think thats it for settings.
The only other thing is the AF360's sensor has to "see" the built in flash.
Sometimes its really hard to tell if the main flash really did fire when you're looking thru the viewfinder. I mean you can tell the flash went off but did it make the exposure? How about take some test pictures with the head of the AF360
actually in the photo. This way you can tell if it really did fire to make the exposure.
In reality for the things you are trying to do, it's simpler to get a TTL cable and the 5-pin adapters and then you can postion the flash where you want it and it still has all the functions of the flash as if its still on the camera.
The AF540 has all of the same functions and all of the same menus of the AF360. The only difference is the swivel on the head, admittedly very handy, and of course its (50%?) more poweful. A lot more expensive though.
Flash Burst Profiles - Pentax P-TTL Flash Comparison
Edit: that video that Jim posted is really helpful i've seen it before but, man he goes thru it quickly so be ready to pause and replay parts of it, to understand it.