Dead Powerbook 170 - Help about the resistor

[neo]

Hello guys, this is my very first post and I really love this forum! So I recently got a Powerbook 170 that seems to be in great cosmetic condition for $20. The seller said that the computer won't power on. I took it home and tried to turn it on by pressing the power button and of course it did not work. I measured the output from the power adapter brick and it shows nothing so its dead. I then ordered a 7.5V power adapter and tried it on the powerbook but it still won't power on - the laptop looks utterly dead. To my surprise, the battery can still hold charge.

I replaced the PRAM battery, tried to reset the battery management memory by holding both reset buttons for 30 seconds - none of them helped. So I completely torn it down and did a careful inspection on the PCB. I didn't really see any burned trace or noticeable blown capacitors. The fuse also measures okay. The only thing that I noticed abnormal is a resistor. It is R160 on the PCB. Definitely looks different from other resistors. It measures about 283ohms. Does anybody know the right resistance for it? If anybody can share a picture of it, that would be greatly appreciated.

 

[beachycove]

Have you tried with no battery in?

 

[neo]

Yes I did but it was the same. I kinda get lost now.

 

[techknight]

Looks like a 220 ohm. But, I would have to double-check some of my parts boards to be sure. 

However, I would follow what circuitry that resistor goes to, if I were you. However, I fear the outcome will be grim at best. 

Resistors dont burn up like that unless something shorts and fails. 

 

[Papichulo]

You try it without the ram card in and is the gray interconnect? cable in right? 

 

[neo]

Looks like a 220 ohm. But, I would have to double-check some of my parts boards to be sure. 

However, I would follow what circuitry that resistor goes to, if I were you. However, I fear the outcome will be grim at best. 

Resistors dont burn up like that unless something shorts and fails. 

Thanks, I had the same concerns but my limited skills cannot support me to find the root cause. I actually went ahead and replaced it with a 1k ohm (before you posted this reply) and it didn't work.

 

[neo]

You try it without the ram card in and is the gray interconnect? cable in right? 

I did, but nothing happened. I ended up replacing the guts with a working but missing hard drive PB 180 (which definitely has seen better days) and it runs okay. My PB170 looks a little weird because it now has two screen adjusting sliders rather than one  :cheesy: