CPU coil resistances

[brew99]

I have two boards with i3 - 7th gen on then. They are from an Asus X541uv rev 2 board.

one board measures 6ohms to ground at coil, and 0.000V in diode mode on both coils (+VCCcore and +VCCGT). Does this indicate something is shorted on both rails, or is 6ohms considered ok for the cpu?

The other board, one coil is the same as above, but the other is 10ohms and 0.023V diode mode.

I always thought that if diode mode shows 0.000V, then it must be shorted, but it shows 6ohms, so is that a short?

I've removed both coils, and know that the short is somewhere down the line which is basically many caps.

Should I inject 0.8V and at what max current to look for a hot cap?

[piernov]

Re: CPU coil resistances

CPU VCore (and some other power rails) will always show a lot resistance to ground. Nothing to worry about, a few ohms is perfectly normal.

[brew99]

Re: CPU coil resistances

Thanks, I just didn't want to apply power until after I had done some diode measurements around the board, and this is the first time I've come across the CPU showing 0.00V although it showed 6ohms, so it got me questioning it.

Plugged it in, and got to BIOS, so that's a good sign.

Thanks for the help

[piernov]

Re: CPU coil resistances

I just read my message again, typo that can be confusing, I meant a *low* resistance to ground obviously.

[brew99]

Re: CPU coil resistances

yup, no problem. I figured that's what you meant

[reassor]

I got lenovo with 10th Gen i5 and it has 158ohm on cpu cores. Is that even in a realm of possibility that its ok?

[piernov]

Possible yes. CPU with FIVR typically show higher resistance than CPU without. (assuming it is Ice Lake)
1st gen also show higher resistance readings.