System hangs and rebooting without battery

[b_o_b]

Hi

I have 1 Pandora with a couple of issues...

1. I am not able to re-calibrate my touch screen correctly - probably needs a new touch screen

2. Without battery - adaptor connected - it constantly reboots - before being able to choose the gui.

3. With charged battery - 800 Mhz - the system randomly hangs. Sometimes it even temporarily hangs - for a few seconds, screen does not turn black- and then continues.. 

So pretty strange behaviour. I am mostly worried about the hanging issue. I don't like the idea of installing new firmware - that might be the solution to the problem - if there is a risk of hanging during the firmware install. 

I will send the Pandora to ED for issue 1 anyway, but I like to be sure issue 2/3 isn't a software problem that I can solve myself.

 

[Asiyura]

2. Without battery - adaptor connected - it constantly reboots - before being able to choose the gui.

The power chipset isn't certified by TI to be able to run the pandora without battery, normal behaviour.Some pandora are perfectly able to run without battery, some are not.

3. With charged battery - 800 Mhz - the system randomly hangs. Sometimes it even temporarily hangs - for a few seconds, screen does not turn black- and then continues..

If it's a CC or Rebirth pandora, you should probably use a higher OPP. If it's a GHz one, just use 1000MHz, you won't gain anything from running it under clocked.

 

[_jr_]

If it's a GHz one, just use 1000MHz, you won't gain anything from running it under clocked.

I do consistently get higher scores (but still far away from C4A levels) on Not Tetris while underclocked

 

[b_o_b]

2. Without battery - adaptor connected - it constantly reboots - before being able to choose the gui.

The power chipset isn't certified by TI to be able to run the pandora without battery, normal behaviour.
Some pandora are perfectly able to run without battery, some are not.

Ah, interesting. I didn't know that. I have 3 Pandora's and indeed I tried another one this morning and it worked flawlessly. I guess issue 2 is a non-issue then.

3. With charged battery - 800 Mhz - the system randomly hangs. Sometimes it even temporarily hangs - for a few seconds, screen does not turn black- and then continues..

If it's a CC or Rebirth pandora, you should probably use a higher OPP. If it's a GHz one, just use 1000MHz, you won't gain anything from running it under clocked.

I am absolutely sure I never had this behaviour before - it is my first Pandora and I always used 800 as default. Nevertheless it doesn't hurt to try.

Thanks.

 

[EvilDragon]

Even if it's at OPP5, unless it's the 1GHz unit, the only safe clock value is 600MHz. Anything higher can get unstable, and as chips age as well, it can be they start to crash at overclock values that worked fine before.

 

[b_o_b]

Even if it's at OPP5, unless it's the 1GHz unit, the only safe clock value is 600MHz. Anything higher can get unstable, and as chips age as well, it can be they start to crash at overclock values that worked fine before.

Ok, thx ED - will give 600 Mhz a try.

 

[rError]

If it's a GHz one, just use 1000MHz, you won't gain anything from running it under clocked.

No efficiency boost like longer battery life or longer chip life? If not, I've been changing my CPU speed settings for months, for no reason

 

[sebt3]

No efficiency boost like longer battery life or longer chip life? If not, I've been changing my CPU speed settings for months, for no reason

Revelent information :

The CPU power consumption depends on its clock speed and its usage: I only have a Rebirth model so I don't know how the 1GHz model performs. The CPU seems to be the most efficient (per MHz) at 500 MHz: it uses about 0.7 W if used 100% at 500 MHz. At a lower clock speed it uses less power, e.g. about 0.5 W if used 100% at 350 MHz. At a higher clock speed it uses more power, e.g. about 1 W at 650 MHz, 1.5 W at 850 MHz. Note of course that in typical usage, the CPU will also be used less if you clock higher; these numbers are for 100% CPU usage.

 

[b_o_b]

Also hangs @ 600 Mhz... so I guess there is something wrong. Hardware? 

 

[b_o_b]

@ED Will send two Pandora's to you tomorrow. One of them is the above - new LCD and the hang issue. The other needs a new case. Hopefully it is not too busy and you will be able to repair them swiftly.

 

[WizardStan]

Also hangs @ 600 Mhz... so I guess there is something wrong. Hardware?

A long time ago there was a bug where the OPP level would get stuck: even standard clock speeds would cause it to frequently crash, and resetting had no effect. For all indications it was running at the correct OPP but it really wasn't. I am about as certain as I can be that the bug was fixed years ago but I don't want to rule anything out before you take the time to ship it. Try this:

sudo su
<enter password>
echo 125 > /proc/pandora/cpu_mhz_max
echo 1 > /proc/pandora/cpu_opp_max
echo 5 > /proc/pandora/cpu_opp_max
echo 600 > /proc/pandora/cpu_mhz_max
exit

You may also want to try and reflash with the latest 1.55 firmware, and then run the update again. It never hurts to reinstall the firmware.

 

[notaz]

Before sending, I would suggest flashing SZ1.55 and taking out the battery for 20 minutes. This should restore software and hardware to known good state. Even if it hangs during reflash it's very unlikely to break, you should be able to restart reflashing process. Even if you can't, you're going to send it to ED anyway, so no loss there.

 

[b_o_b]

before you take the time to ship it. Try this:

Before sending, I would suggest

Thanks, unfortunately I already sent the Pandora's early this morning. Dropped my Pandora pretty hard a few months ago and since then it has become unstable and finally resulted in the hanging problem. 

Mentioned this thread to ED in my ticket.