PowerBook 100 recap pain - any tips?

[Byrd]

Hi,

My brother gave me two PowerBook 100s in great shape, and I'm struggling to get any reasonable results from either - it has seriously made me doubt my troubleshooting and soldering skills which are usually not bad   The caps on both boards were leaking underneath but no trace damage I could see, and I cleaned the boards with electronic cleaning solvent spray + wiped with isopropyl alcohol.

- Both had dead chargers, I recapped these and working well

- PB 100 # 1 - got it and found it chimed but with no display, no HD spin up, quickly turned off after a second.  Recapped everything - got no chime but a flickering display - desoldered caps, checked them out (all good), now get a broken chime and flickering display with rapid power off.

- PB 100 # 2 - got it with no life at all, recapped, display flickers but no chime, promptly turns off.

Any tips for fixing these up?  I'm tempted to go the full board wash next, and gather they are particularly troublesome to repair if received with little signs of life.

Thanks

JB

 

[360alaska]

#1 You must of damaged something when you recapped the second time since you now get a broken chime. Is the backlight flickering or the actual display? Did you recap the display?

#2 try disconnecting the hard drive and see what happens

 

[Ferrix97]

I would try disconnecting the battery first, then the hard drive.

Also, the display panel also contains capacitor that are prone to failing, you loose contrast and you may get some flicker.

 

[aplmak]

Yes the display needs recapping.... there are 8 - 3.3 35v ones I believe... and I use small dipped tantalums and cut the legs very short.. Be careful when cleaning the pads that you don't use too much solution there... It will leak into the display area and ruin it.. so use a lightly juiced up alcohol qtip.. but you will need to clean that area up... they usually turn black on the pads and the solder is hard to get off.. but with patience and good soldering experience it is possible.. I've done like 20 pb 100 screens successfully. I haven't had many damaged PB100 logic boards.. Techknight has had to fix some really complicated broken trace portable boards for me.. but 100's that I have seen rarely had ruined traces.. Check that all your caps are good and right capacitance and so on.. that's my 2 cents..

 

[aplmak]

Also the battery thing works weird.. there is a switch in there to switch to battery when it is inserted.. If there is one in there it will flake out (because the battery is a gonner) So leave no battery in there flip the switch in the back to down I believe with no battery.. But those caps on the display need to be done.. It's a little bit of a pain.. You have to carefully pop off the center plastic piece in the middle of the hinges.. without breaking the plastic clip areas. I also use a small needle to gently pry up the screw hole covers on the front that have softened.. so I can reuse them.. they are mushy. Oh and I forgot there are two caps on the inverter board.. a 47uf and a 15uf. So you have a total of 10 caps to replace in the display housing. 

 

[james_w]

Eurgh I hate recapping PB100 screens!