I need some help with this broken Switch.
I have an short where I already removed the cap, as shown in the Image.
Its the middle smaller cap on the left of Max-Chip above the CPU (on the back side of the board)
Does someone know if it’s the MAX - Chip right next to it or something else?
It does only Charge at 0,46A.
I also have a ‘short killer’ voltage injection Tool, but the only Thing I can See heating up in the thermal cam is the Spot, where I put the probe on.
Can someone please explain where Do I have to inject voltage?
I would pull the both coils and check on which side the short is. the right sides of this coils goes direct to the max ic. The left sides to the SoC.
hi thanks. I think these are also just caps, since other versions of the switch board have large caps there, I think these are just caps wich looks different, or am I wrong?
Eitherways, these are not shorted, only the pads from the cap I removed (On my other board the left side of this cap is connected to ground, here are both sides)
The left sides from the both coils and the middle cap are on the same line. If the middle one is shorted the both coil are also short. The resistance to ground on this line is very low, so it is possible that it apears as short.
ok do you know whats the supposed resistance should be?
Also on my other switch the middle cap doesnt show up as short
The resistance to ground should be something around 60 ohms. The right side of the removed cap is ground.
So Yeah the left side is Shorted. This means the CPU is dead?
You can check the yellow marked caps, but this line goes direct to the SoC. And the 0,45 A mostly indicates a short at the SoC.
Ah Thanks. Do you mean with check to remove them All an See if the short is gone?
Chrcking thrm for short woudnt help I guess, since resistance there is really low or?
What is the resistance to ground at this line?
Hi, sorry I had to Do other stuff.
I measured the line and got this readings:
16.4 to 17.2 Ohm’s.
And I also have a Second Switch with the same short, there I measured ~26.3 Ohm’s.
So are both CPUs Shorted?
Thanks for your help.
So on an original rev Switch measuring standard polarity (black probe on ground) you’ll typically measure somewhere in the region of 40 to 60 ohms (depending on the components used in circuit and other enviromental factors) - anything below that and I would start suspecting a fault with the SoC and it’s very rarely a fault with a cap on this rail
On Mariko/Lites it’s significantly lower, from memory it’s about 20 to 35 ohms… don’t quote me on that
Of course it’s always best to verify these readings yourself on a known good board first before jumping to any conclusions I can only speak to my equipment and cannot account for the equipment your using and any potential quirks they bring to the table - that being said I get generally consistent results across x5 different brands of meters so take that how you will