[paulccpaul]

I was hoping/wondering if anyone might be able to help me out with a couple of problems I am having with two powerbook 12" logic boards I bought off of ebay about 2 months ago. One is a 1.5ghz board and the other is a 1ghz board. The 1.5 ghz board was 300 dollars and the 1 ghz board was only 31 dollars. The 1 ghz board came with a broken power connector and the 1.5 ghz board was supposed to be fully functioning. The problem is that when I recieved the 1.5 ghz board and then proceeded to hook it up, I found out that the backlight wasn't turning on when the computer was being booted. After thinking it was the monitor or cable, I checked it with another powerbook and found out that the monitor and cables worked fine. So I looked at the board and checked where the inverter cable connected to the logic board and saw that on the bottom of the board right where the inverter plug in is, it's missing a transistor type thing. I took it to a powerbook repair person and he said that he could solder it on but he would need a duplicate board because he needed the exact unit that came off ( ithink he refered to it as a CMU or something, he said it was a unit that you have no way of knowing whether its a resistor, transistor or capacitor.) So anyway, I didn't have another board with that part as I actually had tried to solder it on myself and lost it somewhere on the carpet when I accidentally dropped it and it will never be found again as its tiny and the carpet is thick ... anyway, thats where I'm stuck and I'm wondering if anyone can refute that changing this unit might fix it. Ok, on to the 1ghz board. So, on that board I soldered on a spare power connector and everything worked, or so it seemed. Recently I checked my "about mac" info and saw that the processor was actually running at 867mhz. So somehow, I have managed to underclock it. I may have accidentally touched something else when I was soldering on the power connector, but my question for anyone that may have the answer is, where are the multiplier solders on this board? I have searched google but can't find it. And lastly, if you don't know where to find the multipliers, should I really be concerned that its underclocked by 133mhz? It's already kind of slow so I would love to have that speed back, but I'm not sure I want to risk making the machine completely unusable. As for the 1.5 board, I'm hoping I can get a cheap broken powerbook board somewhere, but so far I have come up completely empty. (someone stole an ebay auction from me for a broken dvi board for 35 dollars, they won literally at the last second@! grrrrr) Well if you've read this far I thank you Have a nice day
Paul

[ibook_steve]

Wow. One at a time:

"1 GHz" board: Are you sure it's 1 GHz? Check the video connector. If it's the older mini-VGA connector, you have an 867 MHz board, not 1 GHz. The PLL resistors are nowhere near the power connector, so I doubt you "touched" something and changed the speed. You probably have an 867 MHz board. Mini-DVI was first on the 1GHz board.

1.5 GHz: What is the reference designator for the "transistor type thing" you think is missing? There are lots of components unstuffed on the board, so the component you are looking at could be missing on purpose. It's more likely that the fuse for the backlight is blown. Look for an F* labeled component on the top side near the inverter connector, and ohm across it. If it's blown, you can short across it if you want to try it, but if there's some other problem and the fuse can't blow because it was shorted across, you're going to have a toasty $300 flat brick.

Good luck!

Steve

[paulccpaul]

Thanks very much for the reply ibook_steve. The 1 ghz machine is a dvi model and it was running at 1 ghz before I soldered the power connector on (i was previously turning it on by touching the contacts on the motherboard together). Would you happen to have a diagram or reference for the PLL resistors on that particular board?

As for the 1.5 ghz board, I don't have it with me right now as I'm out of town, but the missing component that Im talking about is on the back of the board directly where the inverter cable plugs in and I checked a picture of a 1.33 board (couldnt find another 1.5) and the component is there... So hopefully it is that. If I remember correctly it's labeled Cxxx with the following x's I'm not sure about. Unfortunately I don't really understand what Ohming across entails and don't understand fuses all too well either. I should probably read up on all of this, but another problem I have is that my soldering iron is not very precise so more than likely, I'll take it to a certified repair person and have them do the solder work once I find a similar board. I have access to a broken 867 board from classified ads but I'm not sure this will work since its not dvi (and its across the country and I don't know if I trust the listing). Although since its just the inverter cable plugin that seems to not be working, I know the problem is on the board (is the backlight fuse on the board?) . I will check the board when I get home next week for the reference number, but again I appreciate your response and anything further that you might be able to add and please excuse my ignorance on this topic I am determined to do everything I can to get this working
Thanks very much,
Paul

[paulccpaul]

if you are still here steve, disregard everything else i have posted, i am just wondering if you might know where the multipliers on the dvi boards are please help me!

[ibook_steve]

Originally Posted by paulccpaul

if you are still here steve, disregard everything else i have posted, i am just wondering if you might know where the multipliers on the dvi boards are please help me!

Two things:

1) I probably can't tell you that because I used to work for Apple and I could possibly still get in trouble.

2) It's not just multipliers you'd have to adjust. You have to adjust CPU core voltage as well. If you don't know what that is or some of the other electronics concepts I brought up earlier, you're not really in much of a position to make these repairs/adjustments. Take the board or machine to an Apple store or a repair center and let them handle it.

Steve