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[urgent] Which voltage regulator on fez panda 1?


#1

Hello,

Sorry to make a urgent topic, but it is REALLY urgent.
I think my voltage regulator on my panda is totally fried.

To be honest it is my own fault, there was 18v connected to the panda’s 5v output. (i know, VERY stupid)
It became VERY hot (burnt my finger) and a xbee died too. :frowning:

Now the board does not work anymore and I really need a new voltage regulator before saturday.
I checked the schematics and it seems there is a lm1117 voltage regulator.

Is that the component right next to the power terminal?
If so I can buy a new one. :-[

Which one should I buy?
http://uk.farnell.com/jsp/search/browse.jsp?N=2031+202724&Ntk=gensearch&Ntt=lm1117&Ntx=mode+matchallpartial


#2

I will be really surprised if the micro is not fried, not the regulator.


#3

How can I test if the chip is alright?
I checked the voltage of this panda with a other board and the voltage output of the vreg on the panda were different then the one on the other board.


#4

Mike was a fantastic help on the chat and we discovered that the chip is fine (board starts) after removing both Vregs (IC3 and IC4) and powering 3,3v from a other board to the 3,3v pin on the panda.

Gus, can you advise me on which one to buy?


#5

Wow the chip survived 18V!! :clap:

You can use any regulator with same voltage and same package. You can see it in pictures at links you gave me


#6

The 3.3V regulator saved the chip. It absorbed the 18V.


#7

Yes it did! ;D
I am amazed how much bad things these boards survive :clap:


#8

So I ordered some voltage regulators (3.3V and 5v) from China.
After a 5 minute fix the board was working perfectly again.

Thinking that I actually really overpowered this board, I am still amazed that it is still working. 8)


#9

Good job on fixing your own FEZ :slight_smile:


#10

It’s worth noting that you could have simply bypassed the Vregs by pushing a verified 3.3V source through the 3.3V header on the FEZ.


#11

Yes, but I did not want to use a extra power supply.
This was a simple fix and the board works perfectly again.