When to replace KBC?

[MDY]

Hi,

Normally when you replace KBC? Which case?

If I have 3V and 5V and laptop doesnot run and doesnot try to run, should be bios or KBC, right?

[highpulse]

Re: When to replace KBC?

not only , if KBC detects something abnormal in some hardware part its suficient to not start . usually you must make some measures on bios and KBC to know if all feeds and signal are present to make the board work . in any case here is a simple turorial

0. When BIOS & EC-firmware 100% are working
1. When EC power is present, his quartz working and EC reading the bios data (look data exchange on BIOS chip an oscilloscope)
2. When ACIN = 3.3V
3. When LID_SW# = 3.3V
4. When EC drop RESET from SouthBridge, т.е. EC_RSMRST# = 3.3V
5. When by pressing of the power button the signal ON/OFFBTN# falls to zero and the same signal is broadcast in PBTN_OUT#
6. When from the SouthBridge signals PM_SLP_S3# and SLP_S5# are drop, i.e. voltage on them will be 3.3V
Under these conditions EC should give command for start.

i hope it helps but there are as well more usefull things to chek , this is a simple chekout

[MDY]

Re: When to replace KBC?

Do you make measure on bios? In Bios only I measure 3V. Can I measure something more?

[ktmmotocross]

Re: When to replace KBC?

u can measure the bios loading with osciloscope

[highpulse]

Re: When to replace KBC?

pin 1 spi , but for that like KTM only with microscope , with VM you can notice very
small oscillation on votlage , but that cannot confirm you much .

[MDY]

Re: When to replace KBC?

Measure the bios loading with osciloscope is good idea? Should I get a osciloscope only for this?
What do you mean with KTM?

[ktmmotocross]

Re: When to replace KBC?

digital osciloscope ffor usb cost about 100e.

if u r not technician it is useless for u

[MDY]

Re: When to replace KBC?

can you give me sime link to see on ebay or internet?