Thunderbolt ports not functioning 2012 iMac

[EMRR]

Odd....shut down for a couple of weeks. First thing I did was install RX 7 when I rebooted, didn't notice TB activity one way or the other, shut down again. Rebooted, TB connections absent.

Neither port will see MOTU AVB interfaces or external drive.
Changed TB cable, nothing.
All MOTU devices and HD's show up with USB or ethernet connection.

System Report/Thunderbolt shows ‘no hardware was found'.
Basic and Extended hardware tests showed no problems.

Did SMC and PRAM resets several times, nothing.

Otherwise, lots of reboots, of MOTU AVB units and computer to no avail.

Any ideas I'm missing? Thanks.

[mikehalloran]

Disconnect all peripherals and the power cord (from the Mac, not the wall). Apple recommends waiting a half hour. Reconnect the power cord & keyboard only.

Reset the NV RAM again. I once had to to this three times with an AppleCare tech logged in and on the phone with me before my ports came back to life.

If that works, get a BR2032 from Amazon. Yours is 6 years old or older. The battery is on the front of the motherboard so, once the screen is off, it's easy to replace. A bad battery can cause all kinds of grief. Because of the heat, no one recommends the CR2032 in these though it does work in a pinch.

If it doesn't work, get it diagnosed as it could be a motherboard. I'd get an Apple tech on the line first in case it can be diagnosed over the phone. Apple phone support is now free. You can schedule a support call on the web site—I normally get a call back in a few minutes.

I imagine you've got someone local you use but there's a guy in Palo Alto I like. I can drop something like this to him on a Saturday morning and pick it up in the afternoon.

[EMRR]

Thanks Mike, I'll try a longer wait before the reset. This was bought as a refurb in 2014, so that battery might be newer, might not.

Next up is a call to Apple once I have time.

Today I'm running everything off the MBP with no problems, which would seem to eliminate a list of queries. I'm still working at least!

[frankf]

I recently returned from a 10 day trip to Brazil. The power was off to my MacPro 6,1 for the time I was away. When I powered up and rebooted, Thunderbolt was unresponsive. Resetting PRAM fixed it. This is the second time this has happened in the past year. I don’t have this problem with shorter time periods.
Frank


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[EMRR]

The down time is very strange. 15-17 days for me. So far PRAM resets aren't doing it.

[EMRR]

This took a logic board replacement to fix......

[mikehalloran]

I recently returned from a 10 day trip to Brazil. The power was off to my MacPro 6,1 for the time I was away. When I powered up and rebooted, Thunderbolt was unresponsive. Resetting PRAM fixed it. This is the second time this has happened in the past year. I don’t have this problem with shorter time periods. ..

Replacing the NV RAM battery will fix this. A BR2032 is around $7 for one or $8 for a 3-pack on Amazon. Because of the heat, the common CR2032 is not recommended in the 6.1 Mac Pro.

Unlike RAM or the SSD, replacing the battery is a multi-step process. Not hard but time consuming the first time. The iFixIt page has a step by step pictorial:
https://www.ifixit.com/Guide/Mac+Pro+La ... ment/21216

Where it shows you to pry up to remove the battery is not quite right. Push the edge through the slot so that it clears the very thin lip or that can crack. There is a leaf spring under the opposite end. Once the lip has been cleared, the battery will pop right up as it should. Replacing is easy—push against the spring and the new battery will slide right in with the lip holding it in place as you release your finger.

Why do it? The battery is very weak. Right now, it's not maintaining the CMOS settings over time—minor inconvenience now but this will get worse. Sometimes, a bad enough battery will cause a black screen on startup. Worst case, the battery can decompose or expand and explode spilling acid onto other components — you really, really do not want this to happen.

An experienced tech may charge up to 2 hours for this job but someone whose done it a few times will take less time than that.

[HCMarkus]

Replacing the battery is a multi-step process. Not hard but time consuming the first time... An experienced tech may charge up to 2 hours for this job but someone whose done it a few times will take less time than that.

Contrast that with the same job that takes about two minutes on a cheesegrater. Apple hardware is always beautiful and admirable from a design and manufacturing perspective, but the iFixit videos are painful to watch when one is accustomed to working on the aging but practical pre-6,1 Mac Pros.

Let's hope the new Mac Pro, if it ever arrives, will not just be a glorified Mac Mini Rack with eGPU.