My USB charger does not boot RockPi and I read that I can apply high voltage to type c directly. May be 12v is ok but I applied 19.5v and burnt some chip
Could you tell me what chip is that? I will order it and try to replace.
Thanks
I burnt RockPi 5B. Need help identify burnt chip
Second question.
Can I bypass that chip and apply 5v to some pin to boot board? at least to test it works?
As per these docs, the burned chip U2602 is FUSB302BMPX (MLP14_2R50X2R50X0R80).
In theory this board supports 5v - 20v fixed voltage input, so this is weird.
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Thank You! I just read it is not a regular laptop 19.5v but 24v used with TS100 soldering iron.
i have exactly the same situation, if there is no short in the vbus, just supply it with a voltage 5 ~ 19V of your preference it should work, if it is shorting you might try removing it (fusb chip). It is just to negotiate the voltage level, there is an LDO behind that to regulate so it should be fine.
EDIT: by vbus i mean the vbus pin of type C port. just supply a voltage of your preference from there.
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Thank You! I actually ordered FUSB and it arrived at home but I am not at home. I planned to replace it. I have never soldered that small chips. It sounds much simpler to just remove that chip from board with hotgun and flux.
I use power unit that shows votage and current and current is always 0
No leds blink on board but when I plugged first time and burnt chip. leds were contunue blinking until I disconnected power.
I guess there is no shorting.
I tried to remove that chip with heat gun. I have small experience removing sop8 flash chips but FUSB chip is not desoldering. I even made it a bit hotter then usual (405 C).
Not sure how hot should I go with it.
UPDATE: DONT DO THIS! DONT DO THIS! DONT DO THIS. YOU WILL FRY YOUR BOARD
i was supplying with 18V DC after and after almost 1 year my board as well went complete potato did you find any solution?
i am thinking of injecting dc directly from those pads: C90480 Caps, they are under the PCB near the coil and accesible, but iam scrared i will fry it more…
Update: tried injecting from there as well, did not work… i need a multimeter…
18V should generally be considered safe. Is something in the circuit shorted or burned?
I guess fusb, i cant test at the moment cos my multimeter is out of battery, but when injected over the cap 19v, the psu made weird noises, guess it was supmpllying the short.
If there is a short i dont see culprit other than fusb chip, filter caps should be fine…
So update:
- 3.3V rail: short
- VCC5V0_SYS rail: short
- VBUS IN: line short
- 4V bus: no short, heathy
So i presume my initial problem was related FUSB, but i made the problem even worse by injecting the 19V to wrong MP8759.
There 2 of MP8759, first one gets the 0-26V generates VCC5V0_SYS, then inputs another MP8759 with this 5V and generates the 4V bus to the RK806 pmic.
The fist one is labeled as U90086 and the later is U90089. See 6 vs 9, great…
and the worse is the Schematics label as 5.5V to 26V capable (may be copy paste from the former U90086), which is wrong, if you give 19V to this bus, you will fry lots of things, which i did, and this line also encouraged little bit.
ie, this 3.3V RT9193 LDO
It is kind of a tragedy that so much effort i invested in this board to make a proper HPTC, but i could barely use it may be last 1 week, just wanted put a proper supply cable and fried the whole board… Kinda pissed though.
BTW, dear radxa @hipboi please remove that 5.5V - 26V text on U90089 input line in PCB schematics. This is obviously wrong
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Marking 5.5V<VIN<26V around the second MP8759’s VIN is very misleading. Allowing 18V into VCC5V0_SYS would be catastrophic, there would probably be very few surviving components on this board… Not sure if the SoC is still alive, otherwise it may not be worth repairing.
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Indeed, the hardware engineer is just copy and paste, more attention should be put on the user who will read the schematics. We will update a new revision.