G3 CPU originally from Beige G3 in a Blue/White G3?

tdbmoss

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Can't find too much about this seeing as most posts are concerned with upgrading not downgrading :) I have a G3 processor with SC530066IP/337-2321 on it (looks the same as the CPU shown here: https://www.ebay.co.uk/itm/391836940520) that I believe is a 300 MHz one originally from a Beige G3, can anyone confirm for sure whether if I were to put this in a Blue/White G3 will it work and/or risk damaging anything, or not?

The jumper block looks to be configured for 350 MHz currently so presumably I need to change that to 300 MHz, leaving it alone would surely be asking for trouble?
 

LightBulbFun

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yeah it should be fine :) electrically speaking you wont blow anything up the worst that could happen is a no POST situation

being its a 300Mhz CPU from a G3 beige it may be a 750A or an early 750P both of which may struggle to clock up to 350Mhz

so you can leave the jumper block as it is but you may experience crashes if the CPU cant handle 350Mhz in which case you would have to change the jumper block.

outa curiosity why are you downgrading? :)
 
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tdbmoss

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Many thanks, I'll give this a try sometime then :) I picked up the system a while back and it had an Encore G4 in it, have now sold the upgrade so am looking to make the rest of it useable to hopefully sell it as a working system rather than just for parts. The Blue and White was actually available with a 300 MHz CPU in the cheapest model so isn't technically a downgrade from what it could have shipped with, but I can only assume the CPUs that Apple used in the two 300 MHz models were not the same given the different bus speed.
 

tdbmoss

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Hmm, it didn't seem to like something about that, don't know if it's just not compatible for some reason or if I did something wring - put the CPU in, set jumpers 1/2/3 and left 4 empty which looks to be 300 MHz, and it switches on but doesn't make any sound (chime/error codes) or show any sign of booting up :-/
 

LightBulbFun

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Hmm, it didn't seem to like something about that, don't know if it's just not compatible for some reason or if I did something wring - put the CPU in, set jumpers 1/2/3 and left 4 empty which looks to be 300 MHz, and it switches on but doesn't make any sound (chime/error codes) or show any sign of booting up :-/
whats the die markings on the CPU? and have you tried setting the CPU Bus speed to 66Mhz?

also you made sure that all 11 jumpers where set correctly right? http://web.archive.org/web/20180821170750/http://drivejumper.com/clockupg3/b&wclockup.html
 

tdbmoss

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It's the same one as shown in the eBay link in my original post if that helps, though not all of the writing is that visible - the rest looked correct yes, I didn't change the ones beyond 1 to 4 though. How do you set it to 66 MHz, all the jumper examples are for 100 MHz?
 

tdbmoss

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That didn't seem to work either, got the same result, but no worries, thanks for the advice! :)
 
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