[rescue] Rescued iMacs looking for input on repair

[Andrew Weiss]

On May 5, 2004, at 1:11 PM, Thomas Gallaway wrote:

> Andrew Weiss wrote:
>
>> On May 5, 2004, at 12:48 PM, Thomas Gallaway wrote:
>>
>>> I just found this about the flyback issue:
>>> http://www.macopz.com/columns/imacrepair/disassembly.html
>>>
>>> An rather scary instruction on how to replace the flyback  
>>> transformer.
>>> _______________________________________________
>>> rescue list - http://www.sunhelp.org/mailman/listinfo/rescue
>>>
>>
>> Yeah... if you don't properly discharge the CRT (either with a   
>> screwdriver and cable or a CRT discharge tool) you can die.  25kV is   
>> not nice going through your body.  They're supposed to have bleeder   
>> resistors but those don't always work.
>>
>> Andrew
>
> Here is another question. The link the guy refers to his mac have done  
> this:
> "If the iMac still fails to boot in the same manner before as the  
> repair (i.e. it turns off just after the light turns from orange to  
> green) then there is still something wrong with the FBT."
>
> Mine does not even get to the point when the LED turns on at all.
>
> -- Thomas
> _______________________________________________
> rescue list - http://www.sunhelp.org/mailman/listinfo/rescue
>
>

Probably just means that a different component on the same board is  
failing.  Many different symptoms are possible when this board goes.   
The only thing that will cut the power to the entire unit after the  
tube switches on is the PAV, however.  Computer logic and the power  
supply don't have the ability to do this.  There are tests to verify  
the Power supply board on the tray loaders in the manual.  IF you do  
the diagnostics and determine the power supply board is the problem  
(using a multi-meter and test points for trickle power and such) ...  
disconnect it from the PAV and try again... most likely the Power board  
will then be fine voltage wise... if this is the case it's the PAV.   
This is something that the Apple manuals don't really tell you but you  
figure out through experience.

Andrew

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and remember: a CRAY is the only computer
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