Sunday, August 7, 2016

Dell Precision System Thermal Solution Compromised FIX

Yesterday my old windows 7 workhorse, a Dell Precision 690 (2 x Quad 3.75 ghz Xeon's/32 gig ram) started booting with a BIOS error:

"System thermal solution compromised. Replace system cover and reboot"

A side effect is that all system fans (they are many and large) go into ludicrous speed and the result is 100db of noise, so you can't really use the computer!

Some quick googling revealed this is related to the system intrusion detection switch located at the rear of the case:


The switch has a plastic plunger that is depressed when the case in closed, open the case and the plunger goes up - triggering the system intrusion function.

No problem - right? I go into the BIOS, system, security, and set the intrusion detection to OFF.
Save and reboot and...same ERROR

Internet suggestions included:

  • removing all USB devices - what  how would that help?
  • Cleaning out the dust (done in the spring during it's annual maintenance &checkup. You do this right?  But it is not a heat problem as it occurs at boot. It the CPU was overheating you would get either a boot at reduced speed or a cpu thermal event error message
  • resetting the cmos
The last one seemed reasonable so i did it by removing the battery and the password jumper. No joy, same ERROR at boot.  I was contemplating removing the massive heat sinks and cleaning the cpu's and re-pasting them as a measure of last resort when my brain finally started working. It's the intrusion detection mechanism that is causing the problem...so

First i removed the mechanism entirely by unplugging the cable and taking it out. Rebooted and the same ERROR. (even tho the intrusion detection is turned OFF in the bios)

So if the bios setting is overridden by the mechanism we have to make sure the mechanism does not continue to think the case is open - viola!  The mechanism is at fault - maybe the plunger is not being depressed far enough or something...

Turning to the IT person's secret weapon - duct tape, we tape down the plastic plunger so it is fully depressed and then put the intrusion detection mechanism back into the computer BUT place it sideways facing the front pressed up against the metal so there is no way the plastic plunger can not be depressed.

We boot and SUCCESS - no error message and the PC is purring along so quietly like it used to do when new...

This problem seems common with all the precision workstation models so try it on your 380 or 490 or what have you.




Digital Music Project - Part 2



Ok after a brief interlude with LP pressings from early 1960's (love how they list the microphones, tape deck, and cutter used to make the record!) we are back with the project. We purchased a TEAC 501 DAC to replace the existing emotiva DAC 1. This DAC has 24/192 on all inputs, rca and XLR and supports DSD (and is reasonably priced - although it has been replaced by the 503).



My goal was to check out HDtracks digital files and DSD files for comparison to other formats. I wanted to integrate this into my existing Kodi media center as much as possible.

Equipment: Dell SFF 765 8gig/SSD/win7 x64 --> Teac 501 --> Emotiva XSP-1 --> Wyred monoblocks --> Waveform Mach + Paradigm Active Servo 15.

First test was hookup to an ancient Pioneer cd/dvda player using digital and optical outs to listen to a bunch of old DVD audio discs. Impressive.



Second test was hookup to Emotiva ERC-3 cd player using digital and optical outs. No real difference noted.

Now to the meat - hooking it up to the PC. The first and biggest problem was installing the driver . Teac seems to have committed a serious boo boo by letting the digital certificate expire so that their driver is unsigned.

Once installed if you go into the control panel's device manager you see the problem. The teacahsd.sys driver is disabled by windows because it is unsigned. This is the latest version 108 of the driver, and i have not tested this on other versions of windows besides win7 x64.



So how do you fake windows into thinking a driver is signed?

The workaround is to sign the driver and thanks to Zhang Pei at http://www.yiiyee.cn/Blog/64signer/ you can download his app and enable test signing of the teacahsd.sys driver. So now i have a working device on my PC that i can select in the Sound Control Panel as the output device. I tested VLC, JRiver, the included TEAC player and Media Monkey and they all worked fine and the TEAC displayed the proper bitrate.

In Kodi you have to go to system, settings and make Audio adjustments to let it pass the bitrate of the source file and not to fix it lower or upscale it. Once i got that set right and choose the proper audio output we had 24/192 audio going to the TEAC 501. Before i did this the bitrate was fixed at 44. The benefit of Kodi is that the display scales well to the LCD TV and the remote operates everything from your armchair, plus once you setup a music source it extracts all the metadata into the library - making browsing easier.

The HD version of Fleetwood Mac's Rumours, in particular with the Dreams track. The vocals were ethereal, the acoustic guitar floated above the throbbing bass line and the occasional bongo drum was very distinct. I was disappointed in the HD version of Billie Jean from Thriller as the bass line seemed slower and had less impact that the remastered CD version. But the opening track sequence on Bad was an awesome bass/drum combo. So i spend the evening sampling a number of HD files and the results were hit and miss, when good they were really, really good - better than anything else i have heard but many were not as good as my CD copy and some were rather annoying - overly harsh treble seemed a common culprit.

I left the FIR settings alone and have not done any fiddling with the box, next steps would be to try and figure out what the optimal settings are?

The external hard disk with all the DSD files plugged into the e-Sata port was not recognized by the PC. To be fixed... as a workaround i copied all the files to the local PC after cloning  the SSD to a larger hard drive and putting that in the box.

Then down to listening. First off the old test standard - Dire Straights Brothers in Arms. I have this on lp, cd, sacd, hdcd and now dsd so it is a good test. The money for nothing track lacked the punch of the remastered CD but the crickets at 3:10 on Across the River were very distinct - much more than on the LP or original CD.

Continuing on with the first Dire Straights i much preferred this digital file to the cd versions. Anyway to cut a long evening short, after listening to all the DSD files i had i came to the following conclusions:
  • Some sounded better, ie more range, cleaner, clearer than the CD or HDtracks version
  • Some sounded worse that the CD or HDtracks or LP version, in particular less dynamics, ie the intro to Billie Jean on Thriller is a good test - the kick drum and bass line should be in your face (or at least in your room)
This may be due to a number of factors, not sure how many of these besides Pink Floyd's the Endless River are native DSD, most are rips from SACD discs and i think some have been converted to DSD from ripped CD's or vinyl. I have no DSD128 files for testing right now as i don't think anything is available yet in that format.

It may also be that the original sources were different (original cd vs remastered cd or lp). Typically i have found that re-mastered CD's usually sound better but not always (for example, i find the Steve Hoffman remasters have rather excessive treble). When we think about it recorded tracks can be re-mixed, boosted, equalized, compressed etc in many different ways and the result sounds different. A good recording/mixing will sound good no matter what. In fact, when switching between JRiver's pure DSD output and Kodi's DSD to PCM output, i really could not hear a distinct difference.

So the TEAC does as good job decoding digital audio from the PC to my analog 2.1 setup. Some recordings are reference quality some are meh. Does this replace my CD and LP collection? No. But it does add a great convenience factor as by using Kodi as the media center i can surf my digital music collection from my armchair using the remote and the sound is quite good. I can also use internet radio and get a good sound (esp from Radio Switzerland, bye bye CBC2), plus the sound from streamed movies and TV shows is quite acceptable.

The only part left to research is the filters which are named fir1, fir2 etc - great naming job! I am sure marketing pushed for names like Tube and Vinyl. Actually, that is what i want - a filter than would make some of the digital files a little softer... maybe this fall/winter may start researching inserting a DSP unit to the chain to pre process the sound before converting to analog.

PS - at first i found the lack of a remote control somewhat disturbing but now i don't. Before listening i turn on the Teac and after listening i turn it off and since it is only used for pc audio no switching inputs is needed and i don't change settings on the fly so all is good.      

And now back to the 50's with Sarah Vaughan....oh my