Fried PMIC

StereoPi hardware discussion
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ChuckE
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Fried PMIC

Post by ChuckE » Sun Jun 23, 2019 8:45 pm

I may have fried my board by not properly shielding it from loose wires. Hopefully the PMIC on the Stereopi is not like that of the Pi 3B+ in that it cannot be replaced without the proper I2C programming. If I replace the LM26420, assuming it is the only part damaged, should the Stereopi boot?

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Realizator
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Re: Fried PMIC

Post by Realizator » Mon Jun 24, 2019 10:36 am

Hi ChuckE,
If your assumption is correct, and LM26420YMHX/NOPB is the only damaged component, then board should start right after replacement. No any tricks with I2C programming here.
Eugene a.k.a. Realizator

ChuckE
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Re: Fried PMIC

Post by ChuckE » Mon Jun 24, 2019 4:20 pm

Great, will purchase and replace. I have an additional compute module if necessary. Thanks.

ChuckE
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Re: Fried PMIC

Post by ChuckE » Fri Jul 05, 2019 8:50 pm

Well, that didn't work. I am now assuming C23 and/or C24 have failed. When 5V is applied it drops to less than 500mV, probably due to limitations of power supply. Hoping that if I remove PMIC, C23, and C24 and apply 5V that 5V LED will light up indicating no shorts. Can you share component placement map to assist troubleshooting? On a good StereoPi board with no compute module inserted and 5V applied, will both 5V LED and 3.3V LED illuminate? Will appreciate any help, ChuckE.

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Re: Fried PMIC

Post by Realizator » Sat Jul 06, 2019 12:23 pm

Yes, both 5V and 3.3V LEDs will illuminate, even without Compute Module installed.
As for components placement - I will prepare these docs for you. It'll take some time, hope to finish this today.
Eugene a.k.a. Realizator

ChuckE
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Re: Fried PMIC

Post by ChuckE » Sun Jul 07, 2019 4:45 pm

Much appreciated! Somewhere it is posted that an alternative to Altium is sought. I have the legacy software of Altium, Protel Advanced Schematic and PCB. I see no reason to pay the high price of subscription to Altium as the Protel software suits my needs. If you are the person that posted that and can save your design to the legacy format, then you might consider using them for minor changes. ChuckE

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Re: Fried PMIC

Post by Realizator » Mon Jul 08, 2019 9:54 am

Hi ChuckE,
Here are top and bottom layers details for you: stereopi-top-bottom.zip
Hope it helps you.
Posting Altium sources is still a question for us, as conversion to KiCad takes a lot of time.
Eugene a.k.a. Realizator

ChuckE
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Re: Fried PMIC

Post by ChuckE » Mon Jul 08, 2019 1:46 pm

Thanks so much, will help enormously. Interesting that when I extracted the files Adobe couldn't open them saying they were damaged or encoded wrong. But Adobe did open the files in the zipped folder. ChuckE

ChuckE
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Re: Fried PMIC

Post by ChuckE » Mon Jul 08, 2019 3:34 pm

Oops, watching Wimbledon and not paying attention. Tried to open MAC files instead of Windows after extraction. No problems with files. ChuckE

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Re: Fried PMIC

Post by Realizator » Mon Jul 08, 2019 3:38 pm

Well, looks like I need to compress files under Ubuntu or Windows, as these "goodies" with dot-suffixed names from MacOS is a headache for users. Sorry!
Eugene a.k.a. Realizator

ChuckE
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Re: Fried PMIC

Post by ChuckE » Thu Jul 11, 2019 4:04 pm

Now that I have removed C23, C24, and C47 I still have the same problem, short between ground and 5V. My board failed after installing a USB WiFi dongle. Should have looked there first. There are no pins to connect to the dongle as it looks like they were pushed down and bent when I inserted the dongle. Photo attached. Now assuming the short is in the USB port and hopefully mine is an anomaly. Will remove and test. Hopefully C23,C24 and C47 are not polarized as I did not see any marking to indicate they were.
Attachments
StereoPi_USB.jpg
StereoPi_USB.jpg (284.89 KiB) Viewed 40 times

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Re: Fried PMIC

Post by Realizator » Sat Jul 13, 2019 10:06 am

ChuckE, your situation with USB connector contacts bending is exclusion in this batch. I can suggest, that this is connector problem (production defect). Let me suggest you replacement board, I will send it to you from our new batch. We expect to start shipping next week. If you will be able to repair your sample, you will have two StereoPis :)
UPD> If you're curious, at this moment from our first 630 pcs batch we have 3 replacement cases. Your case is USB connector problem, and two another cases concerns camera connector problem. That is now we have 0,47% of defective units in this batch. I think this is good quality, and we'll try to decrease this 0,47% in the future.
Eugene a.k.a. Realizator

ChuckE
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Re: Fried PMIC

Post by ChuckE » Sun Jul 14, 2019 10:11 pm

I am grateful for your great customer support. I know that your second batch is expected to start shipping on the 17th as I have ordered a second Stereopi. I am happy to report that with extreme effort I was able to remove the USB port, replace PMIC and caps, and the unit has successfully booted up. I will have to remotely access it through the network connection to see if I have not damaged the camera connections or anything else too severely. Looking forward to working with the units, ChuckE.

ChuckE
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Re: Fried PMIC

Post by ChuckE » Sun Jul 14, 2019 10:16 pm

My order numbers are 76041 and 83924 from Crowd Supply. ChuckE

ChuckE
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Re: Fried PMIC

Post by ChuckE » Mon Jul 15, 2019 5:21 pm

Unfortunately it did not last long, must have damaged board removing USB socket. Hopefully this week for new boards.

stereomaton
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Re: Fried PMIC

Post by stereomaton » Tue Jul 16, 2019 10:24 am

Realizator wrote:
Mon Jul 08, 2019 9:54 am
Here are top and bottom layers details for you: stereopi-top-bottom.zip
Maybe you can add these files to the "DIY Ninjas Section" of the wiki.
They are useful for other usages.
Stereophotographer and hacker
StereoPi Standard Edition + CM3Lite module

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Re: Fried PMIC

Post by Realizator » Tue Jul 16, 2019 7:45 pm

stereomaton wrote:
Tue Jul 16, 2019 10:24 am
Realizator wrote:
Mon Jul 08, 2019 9:54 am
Here are top and bottom layers details for you: stereopi-top-bottom.zip
Maybe you can add these files to the "DIY Ninjas Section" of the wiki.
They are useful for other usages.
Yes, I planned to expand Wiki section with the more schematics details. Now the highest priority for me is a second batch delivery, as there are some issues with customs clearance in China now. There are too many plans and too little time, as usual. :D
Eugene a.k.a. Realizator

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