who knows AHT error code

[Mackata]

Hi,
have a big problem: My Mac Pro 2009 (flashed to 5,1) doesn't start with both CPUs. CPU A alone is OK, as soon as CPU B is activated, I get a kernel panic (see rtf). I did the Hardware test an it shows an error:
4SNS/1/40000001:TCBS-0.000
Should be a sensor I was told but which is it?
My English is not perfect but I hope everybody can understand my problem
Please help me!

Best Regards
from Germany

 

[h9826790]

Hi,
have a big problem: My Mac Pro 2009 (flashed to 5,1) doesn't start with both CPUs. CPU A alone is OK, as soon as CPU B is activated, I get a kernel panic (see rtf). I did the Hardware test an it shows an error:
4SNS/1/40000001:TCBS-0.000
Should be a sensor I was told but which is it?
My English is not perfect but I hope everybody can understand my problem
Please help me!

Best Regards
from Germany

4SNS/1/40000001 -> Sensor error

TCBS-0.000 -> Temperature CPU B... (but I don't know what that S means, may be Sensor)

 

[Mackata]

Does anybody know where I can find the sensor?

 

[h9826790]

Does anybody know where I can find the sensor?

May be..... inside the CPU?

 

[misanthrophy]

Test result below 1.xxx means, check that your CPU is seated properly. (maybe check all the pins on CPU/ CPU tray.

What happens if you swap the CPU's, same issue?

If all fails, it could be a MLB issue.

 

[Mackata]

Sorry, what's a MLB issue?

 

[misanthrophy]

Sorry, what's a MLB issue?

MLB= MainLogicBoard

 

[Mackata]

I just tried the cpu tray in another mac: Same fault. So the fult is obviously on the cpu tray CPU B.

 

[misanthrophy]

Okay, same issue if you change the CPU‘s as well? I mean CPU B in CPU a slot and vice versa. But yea so it looks like your board is faulty. Or you use only one CPU!

 

[h9826790]

Do the swap test.

Put CPU B into socket A (nothing in socket B). If still can boot, then CPU B is good.

Then try install CPU A into socket B (keep CPU B in socket). If cannot boot, then socket B is the problem.

Anyway, did you upgraded the CPU? Are they delidded? Did you perform a close look to the socket? Any damaged pin?

 

[Mackata]

I'm using 2 new X5690 delidded. CPUs are both running in socket A but not in B. I had a close look at socket B and couldn't see something strange.

 

[h9826790]

I'm using 2 new X5690 delidded. CPUs are both running in socket A but not in B. I had a close look at socket B and couldn't see something strange.

If both CPU can work in socket A, but not B, then the biggest suspect is the tray (or socket B).

 

[Mackata]

So it must be the tray, but can anybody tell me where the temperature sensors are? I really had a clos look at slot B but didn't find anything, let the Mac cool down and stripped everything from AC to USB over night and try again...

 

[Mackata]

Sorry, I just see that I made a mistake: The code is TCBC at the end! Sorry!
I found out that it must be a temperatur sensor at CPU B. But where can I find it?

 

[h9826790]

Sorry, I just see that I made a mistake: The code is TCBC at the end! Sorry!
I found out that it must be a temperatur sensor at CPU B. But where can I find it?

Most likely inside the CPU. But the socket / tray can't get the signal, not the CPU's fault.

 

[Mackata]

Any advice?

 

[startergo]

Any advice?

Look at the CPU tray's pins. Any bent or broken pins?

 

[Mackata]

Had a look with a magnifier: All seems to be in correct position, no dust, nothing. Then I put the old CPUs in again and voila everything is OK. I tried 3 different X5690: They're all working in CPU A but not in B.
SMC and PRAM resetted 100 times, Could it be that the firmware is corrupted? How can I reset the firmware after flashing from 4.1 to 5.1. Any danger in that opereation?

 

[misanthrophy]

Had a look with a magnifier: All seems to be in correct position, no dust, nothing. Then I put the old CPUs in again and voila everything is OK. I tried 3 different X5690: They're all working in CPU A but not in B.
SMC and PRAM resetted 100 times, Could it be that the firmware is corrupted? How can I reset the firmware after flashing from 4.1 to 5.1. Any danger in that opereation?

I guess if you want your firmware checked: ask @tsialex friendly if/when he has enough time!

 

[startergo]

Then I put the old CPUs in again and voila everything is OK

What do you mean by this? Is everything OK or not?

 

[Mackata]

No, machine is running with the old E5520 but not with both X5690

 

[startergo]

No, machine is running with the old E5520 but not with both X5690

So with both E5520 it runs fine?

 

[atonaldenim]

Sorry, I just see that I made a mistake: The code is TCBC at the end! Sorry!
I found out that it must be a temperatur sensor at CPU B. But where can I find it?

According to this table of AHT sensor descriptions, TCBC error code corresponds to "CPU B, Core 0 Relative Temperature to ProcHot (PECI)". What that means, I do not know.