[Ti] Ti 800 PRAM

[Kynan Shook]

Don't count on it.  No software test of hardware can come anywhere  
near having a 100% coverage of all possible failure modes.  In my  
experience working at an Apple Authorized Service Provider, all  
software RAM tests combined (TechTool, Apple Hardware Test, the AASP- 
only Apple Service Diagnostics, memtest, whatever) won't even catch a  
quarter of all bad RAM.  Usually we'd be able to find bad RAM with a  
hardware memory tester - you physically remove the memory from the  
unit, then run a bunch of tests.  However, sometimes even that wasn't  
enough, and we'd just have to swap out RAM until the problems  
disappeared.

The bad news is that memory is very easy to test - how do you test a  
CPU with 58 million transistors?  There's no way to know whether  
you're exercising all possible logic paths.  Now add in a PCB that  
might have a loose solder joint, or an intermittent failure of any of  
the literally thousands of parts on the logic board - you can see,  
there's no real silver bullet.  Sometimes something just stops  
working.  Obviously, the more complex items as well as mechanical  
items tend to have problems; hence, RAM, CPU, hard drive, and display  
are all common culprits.  Taking all possible logic board problems  
together, that's another one.

So, give any software tests you have (Techtool, AHT, etc.) a shot; if  
it tells you something is broken, then fix it.  If it tells you  
everything is normal, keep in mind that it will only catch the most  
egregious errors.

The best hardware tests are the ones used at the factory; depending  
on how reliable the product needs to be, they may test every  
electrical connection, the functionality of every chip, and  
functional tests over a range of temperatures, voltages, and  
humidities.  Where I work, I regularly use a thermal chamber, freeze  
spray, or a heat gun to try to get failures to happen.

kalirhe at umdnj.edu writes:
> So, basically - if I can get the Ti 800 started, and install Techtool
> Pro 4, I should be able to pick up any hardware probs?
>
> What kind of problems have people been getting with the logic board?
> The memory is the "Apple-supplied stuff"..
>
> Not such a big deal if the drive decided to go to "HD Heaven", since
> I've been meaning to change the 60 GB one on the 1 GHz Ti G4 and it
> could go to the Ti 800.