Two PowerBooks, Two Display Problems

[Scott Baret]

I've got a pair of PowerBooks, which have a pair of display issues! Both of these have been sitting in my closet for a while but are currently "auditioning" for a spot to replace my deceased 150 as a tutoring machine. They may also wind up being combined into one machine, but we'll see how things go...

The first is a 140. When I first powered this one on, it had almost no display. I noticed the faint outline of the desktop and was able to operate the machine, but only under light. As I continued to use it, the outline got more visible. After about 7 minutes, the desktop began to appear in black and white--but only with the contrast turned completely up. A reverse video outline was all I got when I turned it down. The display got fainter again as I kept the machine on, then got bright again. It's also whiter on one side and flickers a bit.

The other is a 145. This one is brighter on one side than the other. The computer also refuses to start up from floppies, so I'll try another floppy drive to see if that solves the issue.

Any advice on these two? Are they worth fixing or should I get another PowerBook?

 

[mcdermd]

I have a 140 that has leaking capacitors in the LCD assembly. When I got it, there was no display visible at all. Just the backlight worked. I replaced a couple of the bad caps and now it fires up with good visibility but gets a bit brighter once it has been on for a few minutes. I need to order and replace the rest of the capacitors to see if it clears up the issue.

 

[Scott Baret]

I had a feeling it would come down to caps.

I've been running the 140 all evening and it's been consistently showing a good picture. There's some ghosting, but this is a passive matrix display so it's somewhat to be expected. There haven't been any issues aside from having to readjust the contrast periodically.

Of course, I'll have to see how it checks out tomorrow when I thrust it into a tutoring session. I prepared backup plans just in case.

I managed to get around the non-working hard drive by putting 7.0.1 on a RAM disk. The system copies at startup and runs from there, freeing the floppy drive so I can run my programs from there. Thankfully, I'm not using any program larger than 1MB in size, so it's not really an issue (although load times can be a bit sluggish).

All I have to do between now and then is give it a bit of a cleaning. This guy came to me in good shape, but there's some sticker residue on the case that I want to get rid of.

For the short-term, this should work as a tutoring laptop. I may pick up another PowerBook as a backup or get that 145 on its feet (probably with the 150's old disk drive) so I can send this one to be re-capped. (If I'm getting another PowerBook, I'm really not concerned about hard drives working or not although I find the Disk Tools mini install of 7.0.1 superior to 7.1, where I had problems with the sound driver not loading; the new PB would have to be a 140, 145, 145B, or 170 since the other 1xx models need 7.1 or higher).

 

[Scott Baret]

The 140 worked fine today. The ghosting on the screen is really the only problem. It did take about a minute for the screen to "warm up", but I can live with that since it takes about 3 minutes to boot from the floppy and load the RAM Disk.

Still looking at potential upgrades, including perhaps a G3-based laptop if I can find one for the right price.

 

[techknight]

Ya, i think i mentioned in a couple threads that replacing the caps in the display panel would fix the issue, glad to see that one of us tried it and had great results

Also its getting to that age now, that the through-hole and SMD lytics on the inverter/motherboard need an eye kept on, replace as necessary.

 

[mcdermd]

I have a PB100 I opened up for the first time the other day and found a surprising number of SMD caps on the logic board. Sure enough, a few of them were starting to look a little crusty on the leads.

 

[techknight]

yup. time for a recap.

speaking of which, i just recapped a WD-62825 DLP TV which had over 300+ SMD caps. my god, but it restored the picture, and allowed the TV to boot/turn on again, but i lost sound. AHHH gotta chase that one down now...

 

[mcdermd]

recapped ... over 300+ SMD caps

8-o Ugh. That would take me several sessions over many days.

 

[techknight]

ya i know, and the sad thing is now that I have to figure out whats causing the dead sound now. the picture has been restored, and the TV now turns on, on its own. but lost sound.... :?: