820-2132-A, A1229 blinking light on magsafe

[lcdcaps1]

Re: 820-2132-A, A1229 blinking light on magsafe

I have tested the s0 rails for ohms
and they are below
PP5V_S0 2.245k ohm
PPVCORE_S0_CPU 0.5 ohm
PPVCORE_S0_NB_GFX 42.1 ohm
PP3V3_S0 0.7k ohm
PP1V8_S0 1.3k ohm
PP1V5_S0 462 ohm
PP1V25_S0 130 ohm
PP1V05_S0 26.3 ohm
PPVCORE_S0_NB_R 26.1 ohm
PP0V9_S0 1.4k ohm

Hi can someone help me please
I don't know if the following is a real short or if it is meant to be so low
On this model the cpu is T7800
I put one multimeter leads on ground and other on pin 2 on the coil and get the following
L7100 is 0.5 ohm
L7101 is also 0.5 ohm

Does this mean My cpu is dead

[piernov]

Re: 820-2132-A, A1229 blinking light on magsafe

Yes that's a short to ground, it should be at least a few ohms.
I've never seen a Core 2 Duo CPU get internally shorted though.

[lcdcaps1]

Re: 820-2132-A, A1229 blinking light on magsafe

Yes that's a short to ground, it should be at least a few ohms.
I've never seen a Core 2 Duo CPU get internally shorted though.

what could be causing the short
do i remove L7100 and L7101

[lcdcaps1]

Re: 820-2132-A, A1229 blinking light on magsafe

what could be causing the short
do i remove L7100 and L7101

I was looking on the board view
L7100 pin 1 goes to IMVP6_PHASE1 and Pin 2 goes to PPVCORE_S0_CPU
I then looked at all the points it connects to regarding PPVCORE_S0_CPU
I saw that it connects to R1100
R1100 is 100 ohms but i measured mine and it is 000.4 ohms
could this be bringing the ohm reading down on L7100

[piernov]

Re: 820-2132-A, A1229 blinking light on magsafe

CPU_VCCSENSE_P is connected to PPVCORE_S0_CPU inside the CPU, so it's normal to measure 0 ohm between CPU_VCCSENSE_P and PPVCORE_S0_CPU.

[lcdcaps1]

Re: 820-2132-A, A1229 blinking light on magsafe

CPU_VCCSENSE_P is connected to PPVCORE_S0_CPU inside the CPU, so it's normal to measure 0 ohm between CPU_VCCSENSE_P and PPVCORE_S0_CPU.

Hi
do i have a short on L7100 and L7101

[lcdcaps1]

Re: 820-2132-A, A1229 blinking light on magsafe

Hi all
Can My CPU be bad or can U7100 be bad
Please will really appreciate the help from everyone
Many Thanks

[piernov]

Re: 820-2132-A, A1229 blinking light on magsafe

Any components connected to both PPVCORE_S0_CPU and ground could be bad, including the CPU, the low-side MOSFETs of the buck converter, the buck controller the bypass capacitors, …

[lcdcaps1]

Re: 820-2132-A, A1229 blinking light on magsafe

Any components connected to both PPVCORE_S0_CPU and ground could be bad, including the CPU, the low-side MOSFETs of the buck converter, the buck controller the bypass capacitors, …

Hi what would be the quickest way to find out whats causing this
voltage injection could be risky, right ?

[piernov]

Re: 820-2132-A, A1229 blinking light on magsafe

If you don't go above 1.3V it's fine.

[lcdcaps1]

Re: 820-2132-A, A1229 blinking light on magsafe

If you don't go above 1.3V it's fine.

What about amps
Where should I connect My positive wire
on the coil ?

Also should I remove the coils before doing this

[lcdcaps1]

Re: 820-2132-A, A1229 blinking light on magsafe

Hi all

[lcdcaps1]

Re: 820-2132-A, A1229 blinking light on magsafe

Hi, has anyone worked on this motherboard model before
Please

Thanks

[lcdcaps1]

Re: 820-2132-A, A1229 blinking light on magsafe

CPU_VCCSENSE_P is connected to PPVCORE_S0_CPU inside the CPU, so it's normal to measure 0 ohm between CPU_VCCSENSE_P and PPVCORE_S0_CPU.

on another board
R1100 measures normal

[dellxps15]

Re: 820-2132-A, A1229 blinking light on magsafe

what cpu it has ? on all macbook with core duo on inductor cpu i have from 015 to 034 in diode mode values, so if u have 004 i think there is some problem with cpu itself.

try remove both cpu inductor and see wich side u have low value... if its cpu side maybe there is a problem with cpu.

[lcdcaps1]

Re: 820-2132-A, A1229 blinking light on magsafe

Hi
Thanks for the reply
The cpu is T7800
I have lifted the coils
L7100 and L7101

The short to ground is on the cpu side
On L7100 pin 1 is 3.9k ohms and pin 2 is 0.5 ohms

on L7101 pin 1 is9k 9.4k ohms and pin 2 is 0.7 ohms

[lcdcaps1]

Re: 820-2132-A, A1229 blinking light on magsafe

Hi
I have an adjustable power supply (MAISHENG MS3010D) and trying to get the voltage injection to work
I have lifted the coils to isolate the cpu

I set voltage to 0.30v but when i short the leads i cannot get it to do current limiting
so the c.c light does not light but the current shows 0.10A

Can someone help me with this
Many Thanks
i connect positive lead to PPVCORE_S0_CPU and other lead to ground

[piernov]

Re: 820-2132-A, A1229 blinking light on magsafe

Increase voltage to 1.2V. With 0.7 ohms to ground that should generate 1.7A of current and 2W of heat.

[lcdcaps1]

Re: 820-2132-A, A1229 blinking light on magsafe

Increase voltage to 1.2V. With 0.7 ohms to ground that should generate 1.7A of current and 2W of heat.

I cant see any sign of damaged component