flat4

im having some trouble with my Powerbook G4 (15" 1.67Ghz) was running fine since i got it (bought it 2nd hand) then it started to have these weird freezes the other week where the screen would gradually get whiter and whiter until the whole screen was bleached out white, hard reset would get rid of it and then when you reboot i'd get a black screen, everything was running, hard drive, fans etc. just no screen, resetting the PRAM seemed to get me back up and running but it would crash again and again, so i decided to do a clean install last night, got past the first disk ok, restarted and inserted the 2nd disk to complete the install and it crashed as before and now no matter how many times i reset the PRAM i can't get the screen to come back on i'm out of warranty so i'm trying my hardest to fix it myself before i take it anywhere, any clues?

also, the key combos on sartup don't seem to work everytime, i'd say it takes me easily 10 attempts to reset the PRAM, is there a knack to it?

Markus

For PRAM reset I hit the power button (or use control + command + powerkey for instant restart) and as soon as I hear the startup chime I hold down command + option + P + R and keep them held down until I hear the startup chime twice more (so the machine is actually rebooting twice at that point).

It might be worth resetting the PMU (Power Management Unit) to see if that makes any difference at all. This page should have info on how to reset the PMU.

This Apple info doc might be of use as well.

What OS version are you running/reinstalling? If you boot from the install CD, does the screen display anything? If so, have a look under the menus for "Disk Utilitiy" and run it and get it to verify the hard drive, see if it picks up and errors, if so, try a repair. You may also wish to reformat the drive to see if that helps at all.

Then try an install. When you're installing, use the "Customise" option and only install the base OS, do not install any additional languages, printer drivers, or any other software. We should be able to come back later and stick them back on anyway.
This should prevent the requirement of the second disk. When the machine is up, see if it's behaving itself, if so, try and download the very latest upate for the version of the OS you are on. I would suggest not using the Software Update app for this, go to Apple's site and download the combo (or combination) update and then apply that. If possible, copy the update to a CD/DVD so we have a copy if we need it again.

Once you're up to date, see if the machine is still behaving and if so, you should be able to go to the second install disk and install the additional components you need.

Markus

I did a little more digging. It might be the screen connector. There's a thread about this here.

iFixIt Guide is a pretty good site that'll show you how to locate the LCD connector and check it. As it's out of warranty you're probably not too bothered about pulling the machine apart, which is more or less what you need to do to check this.

flat4

i've already had it apart mainly because i thought the keyboard was knackered, didnt see anything untowards with the lcd connector, might have another look inside tonite as a last ditch attempt

not sure on the exact OS but it's Tiger, only problem with booting off the installation disk is that i cant get CD2 out the drive, tried everything on startup, holding down eject button, f12, spacebar, mouse button.....just wont eject the damn thing

i've reset the PMU, not sure what it's meant to do when you've completed it, i just removed the battery & power cable and held down the power button for ages then put it back together again

on the PRAM reset, i've read today that some people recommend holding it down for upto 6 chimes to do it, might give that a go

flat4

reading that thread again maybe i should take it apart first and check the connector, i didnt read the bit where he said he had a similar problem

Markus

One CD eject thing you've not mentioned if you have tried is to hold down the option key, power on the machine (keeping option held down) and then keep it down until you see a boot device selection screen. This could prove tricky if the screen isn't displaying anything though. Anyway, if the screen does display at that point you should see all the devices, and it should display the cd and try eject at that point, see if it helps any.

There might also be a manual eject slot on the optical drive, though you'll probably need to pull the drive out to find it.

Do you have an external display? If you do, try connecting it up and see if you get a display from that. Might at least allow you to see if the thing is still crashing.

One last tip, speak harshly to the powerbook, mention you're about to introduce it's internal components to Mr Fire Axe, it might well then decide to be a good little laptop and work properly

ChefDude

if it's anything like my new vaio, you probably turned off the apple logo in the bios that comes up when booting and didn't realise every fecking driver is dependant on the little bitmap

or it could be a proper problem

flat4

i tried connecting my monitor to it and still nothing but that was earlier on in the day before it went really **** up we have a few things to try tonite before i take the fire axe to it

SwissTony

iTrader: (19)

if you need to do an emergency eject, dont forget the firmware eject commands.

http://docs.info.apple.com/article.html?artnum=106752

flat4

would if i could see the display

SwissTony

iTrader: (19)

just saying, that in the firmware mode, you may see something !!!

have you turned the contrast or brightness down to far???

flat4

no, i've tried booting up into firmware but to no avail

SwissTony

iTrader: (19)

seen a few similar examples, most of the time it is the motherboard or screen.
on the rare occasion it has been the ribbon connectors..sorry to be the bearer of bad news, especially with it being out of warranty

flat4

well....4 hours last night resulted in me seeing the startup screen never, the change startup disk screen twice for a couple of seconds before the screen went white as usual and that's about as good as it got, couldn't eject the disk for love nor money so in the end i opened the drive up this morning and popped the first installation disk in but couldn't get it to startup off that either but only had a few mins before i had to come to work, i've left the PRAM battery unplugged today so that should sort the PRAM out for when i get home, not sure what else to try, doesn't seem to want to respond to key combinations for 95% of the time on startup will have another go at using an external monitor tonite and maybe take the screen apart...

flat4

a bit more reading leads me towards the inverter board being faulty (fingers crossed as they're only 50 quid or so) read someone describe the exact same 'white stain' gradually covering the screen, might have a look to see where it is and check the connections etc.

lightning101

flat4

just over 10 minutes, not bad

flat4

update: had the monitor apart last night to find the inverter, only to find a thread on google about HP owners having the same problem, some bloke discovered that if you clean the contacts of the LCD ribbon cable it will fix the problem, everyone had tried it with great success, so i had a play around this morning (after leaving the PRAM battery disconnected overnight, the only way i can find to get the monitor to turn on again) and got to the choose boot screen (holding down the option button) same as usual happens, get about 5 seconds of perfect screen then the stain eats away at the screen until it's turned white. So i prodded the connector on the logic board and the display came back on, not for long but i could still move the mouse, if i unplugged the cable completely i got same white screen effect, only alot faster (so i was left with the backlight only), now i just need to find out which part of the connector is playing up, the cable or the socket on the board...

damian666

I have had exactly the same issue with a PB G4. The solution was to take a little of the rubbery padding that is on top of one of the components (only a bit mind!!) superglue this to the top of the connector on the logic board (motherboard)

This effectively applies a little pressure on the contact when the case is screwed together.

Works like a charm!
Damian

flat4

good idea did yours get as bad as mine in not booting even when you flash the PRAM etc.? it's just that no matter what i did last night i couldn't get the damn thing to display anything i do have the thing in pieces and was wondering if i need to earth the components by screwing it back together, just don't want to go through all that and it still not work

damian666

Try it...

Apply a little pressure to the connector on the motherboard when the laptop is powered up.

The mac is booting, its just the display that is disconnected.



The above image shows what I mean... the grey bits attached to the hard drive are the rubber strips I am talking about. I cut approx 1.5cm from one of these and affixed it to the top of the connector.

Damian

flat4

well i've done it but i think it's beyond repair now, it's gradually got to the point where it's not responding to anything i do where it used to just need a PRAM reflash to get the display back up, now it's just doing nothing, it responded to pressing the connector the other night but now...nothing, it's either a case of getting an expert to look at re-soldering the connector on the logic board or a whole new logic board (which is beyond my budget) watch out for various parts on ebay soon mother fu........

damian666

Sorry about that mate

lightning101

I finally get to say - "don't buy a mac"

flat4

I also finally get to say - "don't buy a mac"

SwissTony

iTrader: (19)

both of you should be ashamed of yourselves

flat4

it's the first one i've had go **** up on me in over 10 years, shame the same can't be said for the PCs i've had

flat4

all this Mac talk has reminded me to update this thread managed to get a logic board from eBay in the US for £250ish, all fitted and i'm back in business

SwissTony

iTrader: (19)

good man, glad to hear it...it is a PITA when that happens, be it PC or Mac. they are just as bad as each other sometimes...