Devo 8s over voltage input cannot power on

Who have experienced this problem please share experienced.

mangmeephol wrote: This capacitor you can check have how much capacity? I am check this capacitor check no have capacity.

That is noise bypass cap, there will be 0 volts across it. You will need to remove it from circuit and use capacitance meter to check capacitance value but it will be good. No problem there.

mangmeephol wrote: This is problem VDD =2.08v. yes or no?

Yes this is a problem it should be 3.3 volts.

RT9167A-33CB is a 3.3 volt low drop out regulator, its out put should be 3.3 volts.

RT9167A-33CB is change my devo 8s can use ?

Impossible for me to say. PhracturedBlue says full voltage also goes to CYRF module. There could be other damage.

CYRF module has its own 3v3 reg.

Read links I posted. PB suggests the other person remove RF module and see if it turns on.

Edit: Personaly, if you can see or find no other damage I would replace RT9167A-33CB and see.

www.deviationtx.com/forum/3-feedback-que...ower-on-solved#26017

Thank you very very much.

More info, both links have reference Devo 8s

www.deviationtx.com/forum/3-feedback-que...s-to-be-dead?start=0

www.deviationtx.com/forum/3-feedback-que...evo-10-repairs#61461

One also replace a 8050 or 8550 transistor

Had a good look at 8s power schematic and I think your transistors and fet are good and the problem is your 3v3 reg and or after it.

If you have any old or broken device many have 3v3 regs in them like LM1117-3v3. It is possible to cut them from pcb and use this to test, or cut traces and wire it in. To remove devices like RT9167A I sometimes carefully cut all legs (be carefull not to cut traces under component) but one with sharp knife then desolder component and all legs. It is easy and safe it you go about it the right way.

If it works buy correct component and install it.

mangmeephol wrote: RT9167A have 6v. input when insert battery .

To be clear, is this when you insert battery "and" turn on? if so transistors and IRLML6401 should be ok. If RT9167A has 6v input when switch is off transistors and/or IRLML6401 is probably damaged as well as RT9167A.

Red circle in below picture about 6v when switch off
Yellow circle 0v when switch off

Yellow circle about 6v when switch on (this goes to reg)

red/yellow is jumper in schematic

.......

schematic added reg

schematic

Operating voltage of STM32 is 2 - 3.6v so it is right on the threshold.

If stm32 burns, devo 8s still have a chance to repair it back to use as before?

mangmeephol wrote: If stm32 burns, devo 8s still have a chance to repair it back to use as before?

I think stm32 will be ok.
The part is cheap enough and I could replace one, but might be to costly to pay someone.

RT9167A-33CB sot-25 package and S8050 and 8550 sot-23 package on ebay for a few dollars or get through digikey or mouser or similar.

I have many components at home, but if I didn't and it was me I would find a 3v3 ldo reg and connect it with wires and see if it turns on.

Edit: May not need ldo reg to test with full battery.

I saw smoke at stm32 while testing the battery.

Well that is not good.

Not sure how if reg is only putting out 2v ???

That mean end?

This is my reg. 5v.to 3.3v. But 800ma.

Impossible to say from here without looking at it, but if you smoked the SMT32 it is not good and yes it maybe the end. There are cheap transmitters on the market now.

Maybe still try new reg, up to you.

I will offer to buy it for parts. If I can fix it cheap I will send it back.