Help needed - Fried IOIO VREG, store refuses to comply warranty with provided evidence
Armando Rojas
I need some advice about my fried IOIO.
I bought an IOIO from an authorized reseller in Chile (it seems they import the device from SparkFun) and installed it on a flying wing. Its task is to control two servos, one ESC, receive data from an differential pressure sensor and a altitude sensor. The whole system is feeded from a 11,1 V, 1200 mAh LiPo battery. IOIO, servos and sensors are feeded from the BEC in the ESC, which supplies 5V. Connection cables from battery to IOIO weren't larger than 20 cm.
This setup worked normally exactly two days. As I was testing the system behavior constantly, I connected and disconnected the battery several times, until the IOIO stopped turning on. Only worked if it was connected by USB to my laptop or phone. After reading some old threads there and making some tests like measuring the resistance, the conclusion was that probably the VREG was fried. So I went to the store to change it, they said they would examine it to determine if it met the requirements to apply the warranty (no mishandling, no reverse polarity, etc). Before going to the store, I wrote them citing the threads in this group about the VREG frying issue as arguments to my claim in hopes they were aware of the issue. Sadly they said that my case was the first they've ever seen.
While they were testing the IOIO, they sent an email to SparkFun asking some details, after that they answered to me the following points:
- IOIO OTG card has not design or structural hardware errors
- Component TPS62133RGTT is correctly installed to be used with the IOIO OTG hardware. This component is sensitive to voltage changes (greater than 15VDC) or to inverse polarity.
- Component TPS62133RGTT allows up to 15V on its input and gives 5V on its output. This is the damaged component.
As result of our tests we can say to you that the product is damaged because of manipulation, so we can't change your product using the warranty because it is not a manufacturing error.
In my opinion they are correct in the point that the IOIO has no manufacturing errors. But the design didn't take into account the initial voltage surge, and they are saying that the failure of the device is only my fault. I need some additional arguments to make them understand that the product failed under normal conditions of operation - even if the correct components were installed.
Thank you in advance.
Ytai Ben-Tsvi
Indeed some design problems have been identified with the vreg, which have been addressed and a new revision of the board is underway. Both SparkFun and SeeedStudio and myself have done a lot of testing related to this particular failure mode and I believe none of us has ever seen this issue occurring with less than 10V on the input, let alone with 5V. Is it possible that your BEC is poorly regulated? Also, what was connected to the 5V rail and the USB port of the IOIO at the time of failure?
I'm sorry that I cannot decide for the sellers how they handle their customers, but I'm just trying to give you all the information I have with the hope that they'll end up helping you out. Another option is that if you have good rework skills you might be able to replace the switcher and repair the IOIO.
--
You received this message because you are subscribed to the Google Groups "ioio-users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to ioio-users+...@googlegroups.com.
To post to this group, send email to ioio-...@googlegroups.com.
Visit this group at https://groups.google.com/group/ioio-users.
For more options, visit https://groups.google.com/d/optout.
heikki...@kolumbus.fi
I have many damaged vreqs, because it is currently the weakest point in IOIO. But if you are sure that your BEC output is 5V (not more !) why not power the IOIO via 5v-pin (not VIN) to bypass the vreq. I have succeeded to use the damaged IOIO boards this way.
Nothing should be connected to 5V in IOIO (except LEDs), if you connect servos, for example,to 5V, the vreg will be gone.
Ytai Ben-Tsvi
When the vreg fails, it sometimes fails shorting the output to GND, so if that's the case bypassing it would not work, you'd have to desolder the vreg of the inductor.
I have a lot of setups with up to 4 servos connected to the 5V output of the IOIO. From what I've seen this is not a problem when the input voltage is low, but YMMV.
In any case, the fixed version of this circuit should come out shortly.