This should work to revive a bricked PBO as a result of a failed firmware update (wont work if the bootcode is corrupted though).
credit to wigout and snappy46.
Follow the PlayON emergency recovery procedure as outlined below:
Code:
If flashing fails, you can try to recover unit by using safe-mode:
1. Extract install.img from ORIGINAL .zip file
2. Copy install.img to the root directory of a USB flash drive and connect it to PlayOn!HD
3. Disconnect power cable from PlayOn!HD
4. Press the power button and HOLD it
5. Connect power cable from PlayOn!HD
6. When you see the screen saying firmware is being flashed, you can release power button
7. Now PlayOn!HD will reboot and start flashing, so DON'T DO ANYTHING!
The problem is PBO doesn't have a power (standby) button instead it has a power switch (which the PlayON doesnt have and is equivilant to the power cable mentioned in 3 and 5)
Luckily the standby button switch is available (unconnected) on the PBO main board, so you will have to do step 4 and 6 manually.
Here is how:
Remove the PBO from its metal enclosure (you can turn the board over no need remove the fan mount, check snappy46 pic).
Locate switch SW3 on the PBO board.

The follow the steps below

Originally Posted by
snappy46
.. I plan on just using my meter test lead versus tweezers .. since one side of the switch is connected to ground (GND) I was just going to use my test lead with the alligator clip at one end (can connect that clip to any ground surface on the board); and my probe on the other end and touch the other side of the switch. Just in case you are interested here's my game plan in that order:
1) With the PBO ON make contact with the probe and see if the PBO turns off (red light on)
2) Assuming first step is a go; make contact with the probe and see if the PBO turns back on (Green light on)
3) Finally if everything so far worked as advertised; shutdown the PBO with the main switch in the back. Insert a USB stick with a firmware image on it in the PBO. Make contact with the probe and hold there. Turn the switch on the back of the PBO ON and wait for the installing firmware screen to come on and then remove the probe. (Perfect case scenario)
tonytx just confirmed it worked for him.
Best of luck.

Originally Posted by
aasoror
... the circles shows 3 switches, SW2, SW3 and SW4.
Each switch has two solders, apparently one solder is connected to GND (should be determined from the trace lines, I would guess left point looking at the reference picture because its connected to SW4 as well) using tweezers you can just short the switch (connect the two soldering points together), or using the a probe just ground the open end (right solder point of SW3).
....