Beagleboard won't start up.

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1

Hi,

  For some reason my Beagleboard won't start up all of the time when
power is applied. It seems that the 1.8 volt power supply either
never comes up or is delayed by 10-30 seconds. The reset of the
voltages seem to be okay. It doesn't make any difference if I power
it via USB OTG or the external power supply. I'm pretty sure I have a
rev B4 board, it says 500 5000 001 rev B serial 19080040 on the back
side of the board.

  Anyone have any ideas what's up?

  Thanks very much.

  Rick

2

What is the status of the LEDs? Has the board ever worked? Looking at the serial number, this is a very early board. How long have you had it?

Gerald

3

Gerald,

  It was sent to me so I'm not certain about it's history. Is there
some way I can tell what revision it is? It did seem to work okay
when I got it but now seems to be in this flaky mode :frowning: When power is
applied LED D5 always comes on. When 1.8 volts works okay other LED's
come on, when 1.8 volts doesn't come on just D5 is on.

  What would cause the TWL4030 not to start the 1.8 volt power supply?

  RIck

4

I seemed to have stumbled on the solution. I was reading the errata
and noticed that C70 was causing issues. Once I removed C70, the
problem with the 1.8 volt power supply seems to have disappeared! Not
sure why.

5

Rick,

If you haven't already, check the Troubleshooting section in the
BeagleBoard Hardware Reference manual. It has a list of expected
voltages.

It might also be useful to check your +5V supply with an
oscilloscope. BeagleBoard requires a clean, well-regulated supply.
Beware of cheap bricks as they could provide more than +5V and damage
the BeagleBoard.

John

6

The revision is marked to the right of the user button. What is the serial number?

There could be several reasons for the TWL4030 to work the way you describe, one of which could be a bad solder joint. The .4mm pitch devices can be a bear sometime. I suggest that you press down on the U5 to see how that affects the board coming up. If pressing down makes it work consistently, then that is most likely the issue and you will need to send it back for repair.The TWL4030 comes up automatically and needs no other action to come up. If all of the other voltages are OK, then this is most likely the issue.

If U5 is running hot and the other voltages don’t come up, then a short could have developed under the processor keeping the devcie in thermal shutdown.

Gerald