Power source detection problem

My empeg player has once more a problem with the detection of the power source (AC or DC). My player was once in for repair because of this. A buffer chip was blown then. Since the repair it worked as expected.
But now my player always thinks it is on DC power. The switch in the power jack is ok.

The problem is, you can only flash the player with a new firmware if you are on AC Power. (To speed up the boot in the car)
Even with hijack installed it is not possible to force AC power at this stage of the bootloader.

So I can't upgrade my empeg at the moment. Correct? (At the moment hijack is not installed) Any ideas on how to upgrade the player/hijack software?

Maybe the same chip had blown again or could it be another one this time? Maybe someone from support can give me some hints what to check or to replace.

Maybe someone from support can give me some hints what to check or to replace.

Yes, email support, Rob can help you diagnose the issue.

But now my player always thinks it is on DC power. The switch in the power jack is ok.

Is it possible that you have Hijack's "Force AC/DC Power Mode" setting set to DC?

From the Hijack FAQ:

Force AC/DC Power Mode
Allows you to force the player into thinking it's on either AC/Home or DC/Car power when it isn't, and shows what the current mode is. This is useful if you have the hardware failure where the empeg thinks the AC plug is always plugged in, and therefore will always boot in AC/Home mode (see this FAQ entry). Also useful for testing purposes.

Options are Normal, Force AC/Home, and Force DC/Car.


If your adaptor socket is indeed not the issue, my guess is that you have this setting set to "Force DC/Car." If that's the case, switch it to Normal and see if that fixes your problem.

Is it possible that you have Hijack's "Force AC/DC Power Mode" setting set to DC?

That was my first thought, too. But I think some of the things he said indicated that this was not the case:

He said can't even do an upgrade from a cold start on AC power, and the upgrade happens before Hijack takes over. I think he also said that he installed hijack and tried to force AC and he still couldn't do an upgrade even when he did that.

So I think it really does sound like a hardware issue of some kind.

(But Alex, check that anyway, just to be sure.)

As he said:

you can only flash the player with a new firmware if you are on AC Power. ... Even with hijack installed it is not possible to force AC power at this stage of the bootloader.

So even if that is true, it's neither the whole problem nor usable in this particular instance.

Bah. This is one of those days where I should just probably not be posting on the BBS.

Before contacting support by e-mail, maybe someone from this board can help me. (And the support people also read the messages :-) )

One more hint: First of all the effect happend only sometimes, but now in every case.

Myabe your leaf switch is bent. Are you using the power supply that came with the empeg or are you using a third-party one? Using one that's the wrong size has been reported to bend the switch.

No, I only use the original power supply. The Power Jack is ok.

The Power Jack is ok.

How do you know this? The symptoms are consistent with a faulty switch.

Of course, as you said, there was another possible reason this would happen, and this is why your player was sent in for repair before. So it could be that, too. I'm just curious why you're so sure the power jack is OK? What did you use to test this?

The Power Jack is ok.

Not that I don't trust your assessment here, but ow do you know it's okay? I had the leaf switch problem Bitt is referring to and it's different from the buffer chip problem, so the symptoms might not be the same. Is there any way you've been able to test to verify that the leaf switch is definitely not making contact, thus forcing your player into DC mode? From just looking at it, I was never able to tell.

Edit: That's it, Fabris, I quit.

Edit: That's it, Fabris, I quit.

ROFL

Hey, some days, the pebble get snatched, some days it doesn't. No dishonor there.

I know that the effect sounds like an faulty switch.
But I double checked the switch with a voltage and an ohm meter.

Okie dokie. Support it is, then.

If your player has the "developer" software on it, rather than just the "consumer" stuff, then you can still flash a new kernel, with luck.

Connect the serial link, and kill the player (control^C) to get a shell prompt.

Remount the root filesystem r/w: rw

Create a /dev/ entry for the kernel: mknod kernel b 60 8

Use rz, or the (j)Emplode tricks to upload the Hijack kernel to you player, just dump it into the / directory.

Remount the root filesystem r/o: ro

Now program the flash: cat /kernel.zImage >/dev/kernel

After that completes, delete the uploaded file: rw; rm /kernel.zImage; ro

and reboot..

It *might* fail, because there were some minor bugs in the flash driver that got fixed in Hijack (I just don't remember if they were showstoppers or not.. someone should test this sequence on a good player first).. and if it fails, you'll REALLY have to get the power detection fixed then!


-ml

Wrinting to the flash via a device node was in the stock kernel? I did not know that.

Sure, it was there, but they never created a device node for it in /dev/.

But it was also broken in some ways, which I fixed. I just don't remember if the breakage was only when the player was running, or if it was vulnerable at all times..

Ahh.. if the empeg has a RECENT release on it, say v2beta13 or newer, then it already has the flash driver fixes, so the method I described should work.

-ml

The player has 2.00 final on it.
But with this method, I can never upgrade to any future releases, for example 2.01. Correct?

Once you have Hijack installed, you can use my "upgrader" program (Linux) to install any release you like, over ethernet, without wiping out Hijack in the process.

Cheers

I think I found the faulty part. It's indeed the buffer chip. (Hex Inverter lvx04)
Voltage at the input pin (9) is 3.3V, and at the output pin (8) also 3.3V instead of 0V.

But now the big question. Where do I get such a replacement buffer? Is this a standart part?
The other possibility: This buffer chip has 6 inverters inside, I think only one of them is faulty. Question to the empeg team. Are all of them used, or is it possible to extra wire another pin combination?

I'd be more concerned with: Why does this keep blowing on your player and not anyone else's player?

Maybe it has something to do with the power supply I use in my docking station. I could think of a voltage spike during turning off? I'll look at it.

In the meantime I repaired my player. I replaced the faulty buffer. Now the behaviour is as expected.

But I'm a bit disappointed about the support: I received no answer to my mail from the support team within one week. (Maybe the [email protected] address isn't valid anymore)

Happy easter to everybody and thanks for the help

The address should still be valid. Rob's a bit behind at the moment is all.