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Hi all,

 

I have a Performa 5260 that is dead on power on,  no noise, no smells. no activity.  I am more used to Compact Mac's so this is new territory for me.  I was going to start with a complete recapping of the power board and video board and see if anything changed.  I have pulled a few resistors and checked, they seem fine,  I am also thinking C801 and C804 are Rifa caps so may replace them as a matter of process,  I have also checked the fuse at F801 and it is fine.

 

Are there any other obvious areas where these suffer and would cause it to be completely dead ?

 

Any schematics for these ?

 

Andrew.

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your jumping too far ahead here. 

 

We need to go back to basics. As you are aware, these machines dont power on unless you press the power button on the keyboard. 

 

If the logic board is bad, itll seam dead as well. I havent encountered a dead 5XXX machine before, with the exception of a 5300 back when they were still somewhat in active use, as it had a flyback and you could hear the power supply cycling. chirp chirp chirp. So I cant give you exact advice on what to look for. 

 

But what I can tell you is to find the backplane connector pinout online, and then probe around for the standby power signal and make sure your logic board is getting standby power. Then potentially jump out standby to the power-on signal and see if the analog electronics will come up and online. 

 

If so, then its the logic board thats bad. If not, then there is something wrong somewhere else. 

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We need to go back to basics. As you are aware, these machines dont power on unless you press the power button on the keyboard. 

 

Are those boards also relying on some sort of Egret chip or similar ? have had so many troubles with this Egret on CCs and Classic II units, with the same exact symptom (ie no activity whasotever)

Edited by bibilit
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18 minutes ago, bibilit said:

 

Are those boards also relying on some sort of Egret chip or similar ? have had so many troubles with this Egret on CCs and Classic II units, with the same exact symptom (ie no activity whasotever)

I dont recall, I have a few of those boards in my stash so I should take a look. Its possible. 

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Thanks all some good ideas to check.  I have wired in a AAA vision of 4.5v for the PRAM battery and tried to start with the power key on the keyboard.  Absolutely no sign of life.  Will try probing around on the weekend.

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