Upgrade Powerbook Ti 867 to 1Ghz?

[sos_nz]

I took a punt on a used Ti Powerbook, model A1025. It looks and runs great - even the battery and PRAM appear to be functioning OK.

Only minor quibble, it's an 867Mhz model. I have a 1Ghz powerbook Ti A1025 that I can scavange for parts.

So - how easy / difficult would it be to swap the CPU, so I've got a working 1GHz A1025?

Thanks!

 

[CC_333]

I bought a TiBook 1 GHz which was originally an 867 MHz, and the previous owner told me that they swapped in the faster logic board when the original died.

So in other words, it seems that it's possible to do a simple logic board swap, because the two models are identical aside from CPU speed.

I hope this helps,

c

 

[Byrd]

Replacing the logic board will take a good few hours, it requires a complete tear down of the machine. I've owned a 867 overclocked to 1067 for many years, this is also a consideration.

 

[sos_nz]

Thanks for the replies, guys.

Unfortunately I should have posted this in the Powerbook forum - not sure if it can be moved there (Moderators ?)

I'd like to just be able to swap the chip if possible, since my "donor" powerbook's sound doesn't work - only one speaker works).

I'm happy to strip it down, having done so on the "donor" whilst trying to get both speakers working, when I fitted new speakers etc, so I'm pretty sure it's a problem on the 1GHz's board, or with the sound jack. Either way, swapping out the mainboard, whilst giving me 1Ghz, would leave me with mono sound

I'll look into the overclock option...

 

[lameboyadvance]

The logic boards in the 867 and the 1ghz are the same board. The only difference is there are a few resistors on the board that set the CPU speed. If you are good at SMT soldering and have some spare resisitors (IIRC you need 1 or 2 extra resisitors to up the speed) you can swap/add the appropriate resistors and change the speed. With no problems of overheating.

You can even overclock the board. IIRC the board can get to 1100/1200mhz before it refuses to work. (Although you need to find alternate methods of keeping the board cool for that)

I remember finding this info back when I got my 1ghz. Unfortunately the site I found was long dead and only accessible via WayBack, and none of the images worked (which may make locating the correct resistor locations difficult).

EDIT: It seems I saved copies of the sites I found back when I was looking at overclocking. Going through my files I found a copy of http://www.macxtrem.com/articles.php?article=71 which looks like it may apply to the 867/1ghz model.

 

[uniserver]

i wonder if you could use something like smc fancontrol to lock the fan speed high, and run it at 1200mhz

 

[Byrd]

I recall going to 1.067 Ghz was the easiest in terms of resistor placement, but overclocking Powerbook CPUs is not dependant on cooling, as it isn't that great even if the fans run at full speed. You either get a decent overclock or you don't. I'm currently fixing up some Mac Mini G4s (the final 1.5Ghz versions), first one @ 1.67 the other @ 1.83Ghz no problems. The one at 1.67 refused to do a thing @ 1.7 or 1.8 Ghz settings, so I'm lucky the lower speed worked as I had to remove (and lose) a resistor on the top side of the board (not sure if 0K or a particular ohm value).

 

[uniserver]

Yes, i had similar experiences with a 1.25 Mini oc stable to 1.58

and another 1.25 Mini would only run at 1.42

 

[sos_nz]

Yep - definitely a bad sound chip / circuit / jack on the 1Ghz board. I swapped in into the known good body of the 1Ghz, and... no sound at all.

i then put the working 867MHz board into the 1GHz body - and sounds works properly.

I now have a perfectly functioning 867Mhz Ti powerbook, 1GB RAM, running 9.2.2 and OSX 10.5.8.

That overclock stuff looks interesting / not too difficult. Will check it out when I get a bit of time & report back any results.

 

[sos_nz]

I tried to fiddle with the PLL switches as per the link above, but it still seems to be running at 867Mhz.

I've tried checking with Powerlogix's CPU Director (2.3b4 under OS 9.2.2), but it crashes (something about PPC memory mapping).

"sysctl hw.cpufrequency" in a terminal reports 867000.

As it's a 0-ohm resistor, I did what was suggested and just dropped a piece of solder across the "1" switch of the "1" PLL (the 4th row from the top). I then tried moving the resistor from the "0" position in this row to the "1" position, also still at 867Mhz. The computer still boots fine, so I can't be too far off, but suspect I haven't quite got something as it should be.

Here's a cross link to the powerbook forum here: viewtopic.php?f=21&t=22063

I'll make further posts there, since it's the more correct forum. Thanks for the help/advice so far.