2012 MB Air 820-3208-A voltage fluctuations

[2informaticos]

Do you get 25MHz at SYSCLK_CLK25M_SB?
O-scope, or frequency meter needed to properly check it.

Change it, if you are not sure...

 

[da_muffinman]

Do you get 25MHz at SYSCLK_CLK25M_SB?
O-scope, or frequency meter needed to properly check it.

Change it, if you are not sure...

Well I'm not sure...and I'm also inexperienced so I don't know - does testing or replacing the clock chip sound like a good idea to anyone else? I'm at a loss with this one.

The Fluke multimeter is able to measure frequency. SYSCLK_CLK25M_SB measures 0 Hz

 

[2informaticos]

Change that chip is a 5min job; if you have it, from some scrap board...
PCH will not run without that oscillation.

 

[da_muffinman]

I replaced the clock chip U2700 and unfortunately there is seemingly no change in voltage anywhere. Any other ideas?

 

[2informaticos]

When there exists oscillation, you can read 0.75, or 1.75V DC; I do not exactly remember the value.
However, you can confirm its presence 100% only with o-scope or frequency meter.
To get it, U2700 requires 1.8V at pin11, check that.

 

[smiba]

Old post but FYI the meter is probably 100% OK, it usually doesn't damage anything on the meter itself because they know people will at some point put it on a powered circuit by accident. Its readings will just be useless while the board is powered however though

 

[da_muffinman]

Bumpppppppp

 

[2informaticos]

You must check all SPI termination resistors, traces and solders around U6100.
Also try new BIOS.