Macintosh Portable M5120 doesn't want to boot

[MrBlanchet]

Hello there, I've a Mac Portable that has already been recapped some years ago and at the time it was working. I tried to power it on the other day and no way! It just makes a very short noise from the speakers and shows some funky patterns on the screen or other times a black screen and nothing else, no chime, no boot. I've checked visually the board and it seems ok, I tried it with the 9v battery and a new 6v 4.5ah lead acid plugged. What should I try? It's very strange, I was thinking about an Hybrid issue but since it was working after the recap it doesn't make much sense to me... Thanks for your help !

 

[MrBlanchet]

up! still have not figured out

 

[SuperSVGA]

It sounds like unstable power especially if it's inconsistent in how far it starts up. Are you able to check the +5V rail with a multimeter?

 

[Joopmac]

i had this and it was a via in the corner where the interrupt are.. where the hybrid is on a 5120

 

[MrBlanchet]

thanks for the answers, i managed to make it boot the other day but I’ve discovered while using it that it has a very annoying issue… every time a sound is played (ie when i change the volume or open a game) the mac crashes and reboots! what could it be? i’m guessing some sort of corrosion / shorts on the audio circuit but would like to ask you what should i check… thanks!

 

[Joopmac]

Wash it Some extra times
Sometimes I have to wash 2-3x
First hot soapy water and nailbrush
Then alcohol bath 99% 4-8hr

 

[MrBlanchet]

Wash it Some extra times
Sometimes I have to wash 2-3x
First hot soapy water and nailbrush
Then alcohol bath 99% 4-8hr

i’ve already used tons of deoxit and ipa… are there some pins to check for shorts? thanks!

 

[Joopmac]

Yeah, it really takes some soaking sometimes and then even 3 times, dont know what crud is dislodged with that

 

[MrBlanchet]

Yeah, it really takes some soaking sometimes and then even 3 times, dont know what crud is dislodged with that

so I just cleaned another time the board and nada, It playes audio 1 out of 10/15 times, I'm starting to hypotize that it could be an hybrid issue, playing audio drains pretty much current from the battery and this plus a faulty hybrid makes the computer to crash/reboot

 

[Joopmac]

Very much possible, i have 3x 5120 that are acting weird and up for new hybrid
http://jcm-1.com has them in stock nowadays, thats great