Samsung QN75QN95B with One Connect

[lotas]

These modules have 5v DC/DC converters at the input to 3.3v and 1.8v to power the chips in these modules. Open any datasheet for any WI-FI/BT chip and look at their power supply.
Also, USB modules receive 5v, and after the converters, the chip itself is powered.

But this topic was not about the power supply of the Wi-Fi module at all, but about a short circuit on the 17v bus, and this Wi-Fi module had nothing to do with this breakdown.

[Diah]

don't change subject.. again wifi / BT VCC 5V. just stop to correct other with wrong way.. i was talking over this threat and the service manual opened at front of me. lets move on..for the future.

[jason123]

Ok HELP! these caps are 0805 size. One I just took off, measures 21uF!!!
I'm assuming these are 22uF. however, I can't find X7R in that size. Could these by X5R? at 22UF, I'm only able to get 35V, not 50V. Will these work?

[Diah]

search after 22uf 50VDC MLCC SMD/SMT

[jason123]

I did.. Mouser and Digikey list the 22uF in at max V of 35V in 0805 Package - in X5R Dielectric only
Where else do You suggest I search?

[Diah]

at yours scrap boards

or ali

[lotas]

If 22x3=66, bet 15x4 or 10x6

[jason123]

Not much room for stacking under the heatsink. I went ahead and ordered the 0805 22uF 35V X5R (2x the voltage rating of 17V - should be ok)

[Diah]

Not much room for stacking under the heatsink. I went ahead and ordered the 0805 22uF 35V X5R (2x the voltage rating of 17V - should be ok)

its your choice.. but its wrong for me,,, never do it ... .. you ignoring the Resistance between X5R and x7R.. waiting for the result after 1 month or more of daily working

[jason123]

its your choice.. but its wrong for me,,, never do it ... .. you ignoring the Resistance between X5R and x7R.. waiting for the result after 1 month or more of daily working

You're correct, I would never use X5R. I'm thinking the currently installed caps are indeed X5R, and maybe that's why these have failed prematurely.
I've contacted Murata, Kemet, and awaiting TDK - None so far make an X7R in 22uF @ 50V (or 35V.) Leads me to believe the ones on the board must be X5R. Do you agree?

[Diah]

sure agree they dont make it,, but i gave you link at post #46 its exist
use just one from Mouser part 810-CAX7R1H686M670LH if you are hurry

[jason123]

Diah, the height of this part is 6.7mm and that doesn't fit between the board and the heatsink. Current caps are 1.45mm and there is barely any room between caps and heatsink. They actually placed tape between the caps and heatsink to prevent accidental shorting

[lotas]

TPS549B22

[Diah]

Diah, the height of this part is 6.7mm and that doesn't fit between the board and the heatsink. Current caps are 1.45mm and there is barely any room between caps and heatsink. They actually placed tape between the caps and heatsink to prevent accidental shorting

if so as you described any 22uf will be good even 35V