Lattepanda Alpha 864 not powering trough USB-C but powering with 12V DC

If you're having trouble with your LattePanda Alpha & Delta, here's the place to get help.
Forum rules
If you have not found a solution, post a new issue. To speed up the process please let us know:
- Have you tried the solutions listed above?
- What board are you using? Standard (2GB RAM/32GB eMMC) or Enhanced (4GB RAM/64GB eMMC)?
- Have you tried any other solutions?
- How long have you had your board for?
- When did you first boot your board?
- Did it work ok before the issue occurred or has the issue always been there?
- Use images and videos to help us understand the issue where possible

If you are seeking RMA:
- Please open a new topic rather than hijacking someone else's thread
- Mark RMA posts with [DEFECTIVE] + <helpful description of issue>. We can then approve/disapprove each request
- Completed RMA cases will be marked with [CLOSED]
You can find the RMA guide [here]

Resolved Issues
- If you manage to fix an issue, please share your solution for the good of the community. It could help someone else in future.
- If an issue is resolved the thread should be marked as [RESOLVED]. We can then sticky the thread to help people in future.
User avatar
Obakemono
Posts: 7
Joined: Thu Mar 11, 2021 6:58 pm

Thu Mar 11, 2021 9:55 pm

Hello,

I just got a Lattepanda Alpha 864 from a friend who didn't used it much (have been sittin in a drawer from some time now but the last time it was used it powered fine with the LPD included power adaptor).

When i tried to plug it for the first time i found out that it is frozen dead if i use the LPD included USB-C power adaptor (no power, no leds), i've been reading a lot about other people issues with the powering stuff and i managed to improvise powering it with a 12V DC holding the cables by hand as i didn't had the conectors to make the adapter (already ordered) and i got leds and was able to turn it on (i think at least, just tried to verify the board wasn't dead).

I have no other USB-C charger to test it with the LPD nor any other device i can try the included power adapter with so i'm not sure if the power adapter is dead or just stuck in some other power mode (is the one with a lot of modes to negotitate).

The thing is i'm not sure what can i expect:

I have read some people saying that once i power it with the 12V DC i might regain USB-C powering since it can be in some kind of limbo state and might get unstuck, is this really a thing?, like will it renegotiate with the power adapter again?

If that is a no no, it is supposed to work with one of the alternative power adapters recomended and be entirely a problem with the incluede adapter or i won't be able to power it with USB-C never ever again and it should try to RMA it? (i know that is consensus that the included power adapter is bad).

It is an older unit so it won't have any possible firmware/BIOS update in case it matters.

Sorry for the long post and ty :)

User avatar
ccs_hello
Posts: 740
Joined: Sat Oct 13, 2018 9:16 pm

Thu Mar 11, 2021 10:23 pm

Quote: I have read some people saying that once i power it with the 12V DC i might regain USB-C powering since it can be in some kind of limbo state and might get unstuck, is this really a thing?, like will it renegotiate with the power adapter again?

Answer:
Yes, it does not hurt to try this fix.
In one of the "temporary" failure state, it is LP Alpha/Delta's USB-C controller somehow get itself stuck in the "PD Source" mode. I.e., it "thinks" the USB-C port is going to supply 5V DC power to the device connectig to it.
The way to fix that temporary problem is to supply power thru that 4-pin DC_in port (or thru 10-pin battery connector, if LP Alpha). While LP Alpha/Delta is powered, plug-in the included USB-C power adapter. It could somehow un-stuck that USB-C controller and set LP Alpha/Delta's USB-C port to be in "PD Sink" mode (which is taking power feed from that USB-C port.)
If the failure mode was as described, the USB-C is unstuck and the USB-C power adapter will negotiate the USB-C power adapter to supply 15V 3A to LP Alpha/Delta board. That will be fine. Basically, both DC_in and USB-C (now is also power-in) will attempt to supply power and the higher voltage one wins. I.e., the USB-C (now at 15V feed) will win over DC_in (assuming it's fed wih 12V.) The former will be supplying thw power, and the latter is simply sitting there not currently feeding the power. <-- you can safely remove the DC_in power at this point, if you wish. Not problem at all.

Note that, there can be another failure mode which is the inclued LP A/D power adapter itself is dead.
In such case, getting a high quality USB-C power adapter (at least, 15V 3A capable) with a high quality USB-C cable will do.

User avatar
Obakemono
Posts: 7
Joined: Thu Mar 11, 2021 6:58 pm

Thu Mar 11, 2021 10:38 pm

Thank you for the fast reply! :D

That gives me a lot of peace of mind, let's hope it get unstuck, i'll get the parts for the 12V DC adapter in a couple of days.

User avatar
Obakemono
Posts: 7
Joined: Thu Mar 11, 2021 6:58 pm

Sat Mar 13, 2021 5:37 pm

An update on this case.

I received the parts for the adapter today and it works perfectly with the 12V DC, logged into W10 and tested a few things but i tried conecting the LPD power adapter to see if i can "revive" the USB-C powering and nothing, if i disconnect the 12V DC the machine goes off and is cold dead through USB-C, any other steps i can try to force negociating? reflashing BIOS can help? any step i might be missing?

It might just be that the power adapter is dead but it worked fine last time my friend used it so i tend to doubt it, i will try a new different one when i get the chance.

Also, i'm worried about the NVMe SSD temperature (Intel Pro 6000p Series 256Gb), it runs hot like hell (50º+ on idle and it gets to 75º with CrystalDisk Mark), some people say it is normal but it doesn't feel ok, the board is on the open air (no case) and elevated.

User avatar
ccs_hello
Posts: 740
Joined: Sat Oct 13, 2018 9:16 pm

Sat Mar 13, 2021 7:08 pm

Unless you have the proper test equipment (such as WEB-U2 tester), it is very hard to know what's going on.
Try to test it on another LP Alpha maybe?
Other option is to get a "better" USB-C power adapter (15V 3A capable) and a better USB-C cable.
This issue has been discussed a few times.

re: NVMe hot
It is normal. Trying to get a heatsink and maybe, forced air cooling.
If you use a metalic chassis, couple the NVMe device to the chassis with a silicone heat pad.

User avatar
Obakemono
Posts: 7
Joined: Thu Mar 11, 2021 6:58 pm

Tue Mar 16, 2021 1:39 pm

Today i tested the board with a brand new USB-C 15V 3A compatible power adapter but still nothing, cold dead, so my guess is that the problem is not the power adapter.

On visual inspection the Lattepanda is perfect.

Any suggestion i can try? Any way to force the USB-C re-negotiation? Maybe some UEFI command o reflashing can help?

Thank you for the help.

User avatar
ccs_hello
Posts: 740
Joined: Sat Oct 13, 2018 9:16 pm

Tue Mar 16, 2021 2:35 pm

Sorry the new USB-C power adapter did not work out for you.
The mysterious USB-C controller hickup inside the LP Alpha/Delta is a big puzzle for a few people.
My general advise is: if it works, take it as a blessing. Actually, I blame USB-C standards. Overly ambitious, trying to do too many things, pretending it's "universal" but it is not, and many fault cases.

User avatar
Obakemono
Posts: 7
Joined: Thu Mar 11, 2021 6:58 pm

Tue Mar 16, 2021 10:25 pm

I've been trying with some linux distros to see if i could set manually the USB-C mode but none of them list /sys/class/typec (it is weird i guess it should be listed with a modern kernel, just tried with live distros though).

I'll be ordering a USB-C tester as it will be handy to have one around anyway, i've seen the UM25 / UM34 based ones and of course the WEB-U2, i don't really know if one is superior to the others or there are new ones i must look for, i seek guidance in the matter :)

Thank you for all your help!

User avatar
ccs_hello
Posts: 740
Joined: Sat Oct 13, 2018 9:16 pm

Wed Mar 17, 2021 2:02 pm

Changing power flow direction is indeed the USB-C's tricky design (and flaws).
I found playing around the USB-C use cases and gadgets. Sometimes, the faulty situation got automagically removed. At least, temporarily.
For me, using 4-pin DC_in seems to be a good one. Other than that, it's phase of the Moon lucky shot.

User avatar
Obakemono
Posts: 7
Joined: Thu Mar 11, 2021 6:58 pm

Mon Mar 22, 2021 1:48 pm

I got a cable on the mail today and i have been able to test my phone on the lattepanda usb-c port, it works, the phone charges and i can transfer data so the port itself is not dead (not dead dead at least).

And here is the funny thing, i boot into W10 with the 12V DC and then can connect and disconnect the USB-C power adapter as much as i want and nothing happens but if i connect my phone on the USB-C port then disconnect it and then connect the USB-C power adapter the board instantly goes off as if it tries to change the power source and somehow fails.

I'm still waiting for the USB multimeter to arrive, i might try and poke around with a regular multimeter (not sure where though xD).

Post Reply