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max1zzz

iMac G3 (Rev A -> C) G4 CPU Upgrade

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I wonder if this is just the system reporting incorrectly, but it has done it a couple of times. The first five minutes after boot up the CPU seems to run at 538MHZ and once it warms it its goes down to 532. I would call this thermal bottlenecking, but I don't think the CPU can even do that? Maybe a voltage spike after boot up? Anyone know?

post-6354-0-00095500-1484793293_thumb.jpg

Edited by belgaonkar

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very nice to see the iBook running :) do note that the thermal diode on 750/7400/7410s are not calibrated normally so i would not really believe that thermal read out. in regards to clock speed i think its just variants in the program try comparing it to another program and see what it reports, the CPU is not adjusting any multipliers as your with in points of one and the 7410 only goes up in increments of .5. btw i see its recognising your L2 cache does OS9 system profiler report it? and is the firmware on this iBook fully up to date? just collecting some information :) also got OS X installed? it would be cool to see esp leo :) (btw how is thermals under a stress test? and once OS X is on there geekbench it :) )

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Firmware is up to date, still waiting on the RAM upgrade to come in the mail. Keep in mind this is the original non firewire model meaning it cannot even run tiger unless the ISO is modified. The machine seems to over heat when doing intensive tasks like an OS install. I am currently working on replacing the speaker with a small fan.

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Cool. So your running firmware 4.1.9 then? im well aware That this is a PowerBook2,1, in that regard you dont have to modify the tiger ISO to install Tiger on it, with a couple OF commands you can temporarily fake your machine as a PowerBook2,2 and install tiger using a stock tiger CD. (well one long command actually yay for forth you confusing little...). do you have a shot of system profiler in OS 9? im want to see if it sees the L2 cache and if it reports the CPU speed correctly with the firmware fully updated. (as the speed and L2 where not reported properly with Maxs iBook and i suspect thats because he could not update his firmware for some reason) im still waiting to try a G4 upgrade on a (slot loading preferably) iMac G3 at some point. kinda surprised to see the L2 cache being able to run so fast would be fun to see if it could be upgraded to 1MB of L2 and i hope you can get the thermals under control not surprised to see it struggling with a 533Mhz 7410 LOL

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Minor update.

 

My contact for the reball work received the G3-400Mhz board and Freescale G4 cpu. He is a bit back logged, but, I plan to start extracting the G4-7410LE 533MHz cpu from my harvested graphite board here shortly.

 

I have all the tools to do the extraction and now just need to block out a day to get it done. I'm gong to try taking out the cache chips as well, since the board is going to be ditched anyhow. I might try and scavenge the resistors for the clock speed settings, as those might come in handy if I bugger the ones on the Pismo board.

 

Any tips on replacing the soldered cache chips?

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Yep, drag solder them. Desolder the old ones, clean the board with desoldering braid, put the new chips on the board and run a bead of solder over all the pins then go over them with desoldering braid. This should leave you with nice neatly soldered cache chips :)

 

That said, i'm not sure the cache chips where causing the problem I got belgaonkar's board to run at 533mhz with no problem and that was originally 300mhz

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So how do I go about re-soldering the cache chips back onto the Pismo board after I clean it up? You don't "reball" them as such, but, do you "add" solder/flux to the existing cache chips and then heat them up?

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You usually leave the chips alone.

If you are using hot air to put the chips back on just tin the pads, drain everything in flux and heat up.

Or you could do it as max said and drag solder those guys back in place. For that you usually start with bare pads. Just add flux, tuck the chip down by the edge pins and then just run your nicely tinned iron along.

You would not add solder to the chip in that case either.

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I am going to wait and see how the existing 400MHz G3 -> 500MHz G4 upgrade goes and then test it out. Then onto the other Pismo board that has the 500MHz G3 with the faster cache. If  there is no difference, then I won't bother with the chips.

 

I am on the road to 550MHz G4 for at least one of my Pismo Powerbooks.

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@Lightbulbfun how did you get 10.5 on your Powerbook? The optical drive must be a CD rom drive and you must have hacked the leopard installer? Tiger is much easier to do, but I have been unsuccessful in making a leopard installer. Did you use a firewire iPod? I got to 10.4 but can't figure out how to get to 10.5

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with a cloned install of 10.5 on the drive the iBook should boot right up its a uninorth machine, all the drivers (apart from video drivers) should be in Leo already, in regards to the PowerBook Pismo IIRC i booted off of a USB stick from the built in USB 1.1 ports then before it found root via UUID of the drive i quickly plugged the drive into a USB 2 CardBus card i had installed and then let it find root and it booted up and installed  (of corse i had to fake CPU Speed). the CardBus card was not directly bootable from OF. hope this helps heh

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bit of a status update and some good news. so id like to report that the G4 upgraded Pismo has been working nicely since i did the CPU swap on it (never had it kernel panic for example) but the non working L2 cache was bugging me so yesterday i decided to fix it :) based on other reports of L2 cache failure on Pismos i decided to reflow the CPU again and a little bit of the surrounding circuits around the CPU and that seems to of done the trick its now fully reporting L2 cache and no POST failure messages :D here are some Pictures and geekbench results showing the improvement L2 cache makes

 

http://browser.primatelabs.com/geekbench2/2625052

 

http://browser.primatelabs.com/geekbench2/2625050

 

IMG_0119.jpg

 

 

IMG_0116.jpg

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I just got my board back from a fleabay service provider who reballed/reflowed a freescale G4 500MHz cpu onto my spare 400MHz Pismo board.

 

Delicious... and cache is working fine. He did a solid job and the price was SUPER reasonable. ($55 + S&H US)

 

Onto my spare 500MHz board and to see if that works like I hope. Then I get to set upto reballing a salvaged 533MHz CPU and cache.

 

sysinfo2017g4400

 

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Very nice guys :)

Maybe my initial problem with the iMac was a bad solder joint then

 

I'm thinking of trying this with my kanga (if I can get it to boot correctly), as far as I can find it has a regular 750 - but I can't find any high res logicboard shots to confirm.

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thanks :) just got semi finished with the iMac sadly it does not boot (CRT energisers and i get a pop from the speakers but thats it) so iv just tried reflowing the G4 chip one more time to see if that will work (currently waiting for the board to cool down again) Just wondering if i cannot get this iMac to POST how up are you for doing it for me? as this is a Machine i very much want working (its my Flower Power iMac) im fully willing to pay for your services in some form (ill provide the G4 ill even give you 2 G4s and plus the One on the iMac if you want) I just really want this board/iMac to work LOL. in regards to the Kanga from my kanga although i have not taken it apart the G3s PVR tells me its a regular 750 and an early one too 2.1 Rev  vs 2.2 that was in my Beige G3 so its most likely going to be a 2.6v 750 so you will have to find a way to lower the Core voltage before fitting a G4 hope this helps :)

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Just tried the board again and sadly it does the same thing :( at least its repetitive (ie it does it every time) and nothing has gone up in smoke as far as i can see so i have not shorted any main power rail to a sensitive data line for example... i think LOL I do see 2 bridged balls on the outer rim of the G4 but i dont have any way of clearing that without lifting the chip and doing it all over again using up another G4... so id like to see if Max is up for trying first

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I'm happy to give i a go if you ship the board to me, I can lift up the chip and try reballing it but I may ultimately have to replace it as i'm not the best at reballing (but I did successfully reball a 7410 yesterday)

 

A couple of G4's sounds like a reasonable price (damn things have got harder to get hold of in the past couple of months)

 

Just need to check if your board will work in my iMac G3 (it's a first gen slotloader)

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Oh awesome :) tho its a FP iMac its the Non US model so uses a regular 360 BGA 750 and backside L2 cache it has the model identifier of PowerMac2,2 (the first gen slot loader is 2,1 but the Lobos are swappable I also Just talked to a guy who has been an AASP guy for many years and has worked on many macs and he says there compatible too) so yeah if you could DM me your shipping addy and ill get the board and 2 7410s sent to you asap (ill also DM you my addy once i have yours) PS do you want me to cover return shipping or are you ok with covering that? (Im going to cover the shipping cost of shipping it to you of corse) how does that all sound to you :)

Edited by LightBulbFun

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Regarding cache speeds, is there something in either the Pismo board or the Pismo firmware that would clock down the cache on a 400MHz board vs a 500Mhz?

 

It was my understanding that by setting the jumpers/resistors to 500MHz would increase the clock multiplier for the cache as well as for  the CPU. Is this not the case?

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AFAIK cache is tied to the CPU speed (CPU speed goes up so does cache). how far the cache can go im not sure on one hand most of the reports I have seen say L2 cache G3/G4s dont over clock that well on the other hand we do have the G4 Upgraded iBooks rocking G4s at 533Mhz with L2 cache near 300Mhz  But I dont know if L2 cache is properly enabled on those i did ask for details from the guy with the 533Mhz one (as his showed a Gauge pro reporting L2 cache) but he never responded.

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AFAIK cache is tied to the CPU speed (CPU speed goes up so does cache). how far the cache can go im not sure on one hand most of the reports I have seen say L2 cache G3/G4s dont over clock that well on the other hand we do have the G4 Upgraded iBooks rocking G4s at 533Mhz with L2 cache near 300Mhz  But I dont know if L2 cache is properly enabled on those i did ask for details from the guy with the 533Mhz one (as his showed a Gauge pro reporting L2 cache) but he never responded.

 

This is why I am leaning towards harvesting the cache from a 533MHz G4 Powermac board along with the CPU. The thermals are also inline with the other research I have done. And the voltages are just fine.

 

I thought there was something in the firmware or such that would detect cache misses/errors and then drop it down a setting at the OS.

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another status update still mucking around with the Pismo :)

 

I got the thing clocked up to 600Mhz! its quite fast at that speed especially with the 1MB L2, I did get it benchmarked in tiger. tho while doing so in Leopard the L2 cache died again mid benchmark and crashed OS X LOL and when i rebooted it had same symptoms as before so prolly a dodgy ball again, so ill give the CPU another reflow tommrow :) kinda glad it was the L2 and not the CPU it self as the L2 is a known issue not related to clock speed (the fan had not even kicked on at the point it panicked). this is still with the original stock L2 cache chips as it was back when it was a 400Mhz G3 board I have not replaced those or anything.

 

BTW I noticed on both the Pismo and my iMac with gauge pro in OS9 it will report the bus/cpu frequency a bit higher then normal for the first couple minutes of running then it will settle to steady normal 99.9Mhz Bus speed in the case of the Pismo and iMac im not sure if this is a bug in the app or really is the bus speed being a bit lose for whatever reason.

 

https://browser.geekbench.com/geekbench2/2625681

 

IMG_0141.jpg

 

 

IMG_0139.jpg

 

 

IMG_0140.jpg

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