Instability with big heatsink

#21

If anything, that is about the opposite from what I would expect. It should be MORE stable at lower temperatures. Suggests to me that something is being shorted out.

I don’t know the details of most of those chargers, except that most or all of them appear to contain some form of “smart” to them, which ultimately can do nothing but muck things up. Further, they are all likely to start at 5v output until they are instructed to step up the voltage.

The schematic for this board calls for 12 volt power input. 12V input runs to a pair of 5 volt buck regulators. While the datasheet for the 5 volt buck regulators isn’t explicit in this, at every instance they show an output set to 5 volt, they are showing a minimum input of 6 volt. So if you’re feeding the board with a 5 volt power supply, the output of those buck converters is probably somewhere in the range of 4-4.5 volt, which is too low. While the instruction manual may indicate that USB PD/QC/etc. adapters are compatible, the startup state in ALL of them is to output 5V. This is so as not to cause damage to devices not capable of accepting the higher voltages.

Now the board does have an LDR6015T PD controller;

That means that it is supposed to signal the power adapter to switch to a higher voltage.

HOWEVER, the functionality of this part is subject to a whole bunch of other conditions being met, none the least of which is the fact that your WIRE needs to be implemented correctly.

If it were me, what I would do, is rig up a true 12 volt 3 amp adapter, and wire it straight up to the VCC12V_DCIN contact point beside the power measurement resistor (R2).

#22

I have an old USB C power cable that my dog chewed, I salvaged the plug on the end, can I apply 12v directly to the black and red wire in this cable?

Or does the LDR6015T need to request a higher voltage before it can receive a higher voltage?

#23

I have an intermittent instability as well. Most of the time it works fine, but sometimes the whole system just halts (a hardware stop, not a kernel panic or a segfault). I have no idea what is causing it, though it seems to happen when the system is under load. I have the AllNet case with the built-in heatsink.

I am the “someone [who] was complaining about it not coming with spare parts” (@lbdroidman above) so I may have damaged something in my multiple attempts to build my system. I’ve been used to getting a RPi board and just screwing on a case. It seems that the Rock Pi requires mechanical engineering skills to assemble.

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#24

No. It just needs you to use something a little more sensitive than a sledge hammer to assemble it.

#25

The only thing that the LDR6015T does is tells the power plug that it is OK to send a higher voltage.

Your dog chewed wire should be fine, HOWEVER, I suggest that you confirm that the red and black wires are, in fact, the positive and negative power wires. Its a bad idea to make any kind of assumption that the manufacturer used predictable color coding. I’ve seen USB wires with all kinds of random colors.

#26

Kids under 10 can assemble it

Amazing where the world goes…, I just wonder you use words “mechanical engineering skills to assemble” but are unable to assemble

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#27

Not to worry, he also lost parts in a carpet, probably instability due to damaged caused by zapping it with static electricity.

And besides which, I’m no mechanical engineer (I’m not even sure why mechanical engineering has anything to do with this…?), yet I manage to solder 30 pin IC’s with 0.5mm pitch successfully onto circuit boards with shakey hands and being all thumbs. A surgeon, I am not.

And I’m also pretty good with a sledge hammer.

#28

hope nothing else breaks due to other equipment, like a table where his rock rocks

#29

Seriously, if you guys are justifying a serious design fault by saying people are too rough, then you have bigger problems than I thought.
But whatever helps you sleep at night!

#30

Not every product is a good fit for every person. Some people ARE too rough, and no matter how robust you manufacture something to be, there will be people who stress it beyond what it is capable of. That’s not the manufacturer’s fault.

#31

Come on, you even admitted there was a problem by revising the heat sink to remove the corners.

But you’re right I guess it’s my fault I should have known those screws were too long for a reason and not put washers under them.

In any case I won’t be buying any more products from radxa that’s for sure.

#32

Show me where I said that.

#33

When you buy malfunctioned device, you normally do comply about it. When you break your own device, you never blame yourself, it is always somebodies fault, just not yours. Being clever, you show your unsatisfaction by saying that you will never buy hardware from that manufacturer.

I guess that is all or did I miss anything? If there was no manual, how did you know if you have waranty or not? If there was no maual, how did you know which screws do what and why did you try to find it out by assembling instead to write email to manufacturer asking for guidance? Why did you keep it instead to give it back and ask for refund? How did you inform yourself about this product? Have you ever assembled before anything and did you read manuals for that or was it learning by doing?

I guess those are questions, which if you reply, you will find out what went wrong and how you end up as unsatisfied customer. However, nobody of users of this forum has anything to do with your troubles, write your complaining emails better to radxa instead to keep the flow of your frustration on users here.

I dont care if you buy products from some company or not, but I hope for you that you will find a perfect manufacturer and a product by proper research before buying.

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#34

Cevap is not just a number!

#35

For what it’s worth, I replaced the choke and it made no difference whatsoever, so I guess that wasn’t the problem after all.

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#36

One year later another detail:
After finally assembling my Rock Pi 4 the network was gone, no lights on the jack at all, no connection. The soldering pins of the network jack touched the heatsink (the big one from Radxa) and got shorted.
I took it apart once more, trimmed those and some other and network was back.

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#37

Thanks for the feedback. We will try to avoid this in future version of the heatsink.

#38

In my opinion: the heatsink is innocent. The extra long soldering pins of the network jack are guilty. :wink: