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Ah yes, I was wrong - I was testing the reset, confused by the Apple schematic :) thank you for that! I found the NMI line at pin 37 of ‘Misc GLU’ - I couldn’t find it at SCC? Seems to be changing when pressed but I don’t think it’s properly ‘high’. I checked with my multimeter and it’s...

Hello techknight, djacobso, and TrueNorthSouth, Can I ask, please - did you happen to end up dealing with either of the two Portables mentioned in this thread? I’m confronted with the same error. Already replaced all capacitors, currently using it as a parts donor for trying to fix another...

Thanks - I don’t think I did the rear film on that one, but I replaced both on a different LCD recently also with yellowish results. I think I just need to find a better source of film. Meanwhile, we’re off-topic for this thread - sorry about that - I just got excited thinking perhaps someone...

Ahh… I’ve found the same, experimentally. Removing the ruined polariser from, say, a Powerbook 150 passive-matrix screen seems to expose an additional grey layer that is also ruined and has to be scraped away. I was thinking that was the film-compensating layer (of FSTN) but I had seen the name...

The brightness control for the replacement driver probably expects a voltage 0-5V? While the PowerBook’s control is probably producing a constant-voltage, PWM signal. Maybe tie it to 5V, perhaps using a voltage divider pair of resistors from your VCC. Perhaps also see this post in the thread...

Thanks - did you mean me? :) I’ve replaced all those except the TDA4605 (which is on order along with Zener diodes). In the Classics I was working on, the 5V slowly increases rather than oscillating. When it hits 4.7V, the machine boots, and I don’t have any rebooting after that. I do have a...

I’ve already replaced all caps, so it’s not that for me :) but thanks for your report anyway. The biggest 400V cap seemed to solve a brightness-flickering problem; I haven’t found any specific capacitor that makes a difference to the voltage and wobble. ‘Jitters’ can be caused by a poor...

Ah, you mean the one near the optocoupler? Many people fix the problem by replacing the optocoupler, or the signal diodes connected with the optocoupler (and the cap you mentioned). Nothing has been a complete fix for me, but certainly it’s worth a try. I tend to think of the Classic analog...

Sorry I missed this question - No, I don’t have any recapped Classics that are working properly. Yes. Only one machine turned on at all before the recap (with a checkerboard display), the other three would not turn on (just ‘dead’). After replacing the caps with Jaycar caps in all four, and...

Welcome, falen6 :) Yes, I still have several machines with the identical symptom, I haven’t got around to fixing them yet. I’m really not clear which part actually fixes these - it sounded like resoldering the wires was part of the final solution. I have one that I’ve thrown many parts at...

Yes; well done, I’ve yet to successfully repair a Classic analog board :) I haven’t replaced any TDA4605s yet - sounds like I need to find a source for those. I’ve tried everything else except some of the diodes (particularly the Zener diode was going to be next on my hit list when I get back...

Hehe - I’ve had similar - the funny thing is that we’ve both used the same dark-green-coloured ‘low-ESR’ caps, which I bought locally from Jaycar. What if they’re our culprit? :) I shall order a replacement for DP12 from Mouser this week.

Never mind, sorry. I edited my message - I was confused with the schematic for the Plus. I have one of those with a wobble too, which goes away as it warms up. I think RP2 in the Classic is just a safety device. I’ve noted DP2 and DP12 in my message above as possibly being the ‘jumpstart’ for...

I think the owner has even more, I just have four of them to deal with for now. All had leaked capacitors and, except for one, would not turn on at all until the capacitors were replaced. Now they turn on, but with wobbling screens/low voltage. I haven’t replaced the TDA4605. Have you? Since it...

I don’t try to picture anything! 😁 I’ll be just so happy when you find the cause (although it seems there are many causes for the same problem) - I have four Classics waiting for me to fix the same fault on all of them. I’ve spent so long replacing caps, optocouplers, etc. I could try using a...

Nice find! :) I especially enjoyed (translated) “The acid infiltrates everywhere and every time you use the soldering iron, an olezzo of burnt cat piss will come out.” However, do note that the page mentions the same problem after replacing those parts; “I am therefore replacing the following...

I’m excited about that too - thank you for updating us and best of luck! I tried to buy freeze spray, but can’t get it here in New Zealand any more due to regulations.

Yes. The two I was trying to fix are still exactly like that. Slowly-climbing voltage, screen still wobbling even when over 5v. I don’t get it. In the split second when there is still a picture after turning off the power, it doesn’t wobble. It is also not quite the same wobble as shown on the...

Thanks for that :) appreciate the insights

Fair enough, you’re right - and I am glad to hear that you keep the hard drives - it would be a great shame to throw them away. Nothing should be thrown away :) I think the biggest Powerbook 100 problem is with the LCDs. I’ve had two corrosion-affected displays and I currently have one with the...