Fixing the Powerbook 170 LCD Screen - Tunnel Vision Issue - Plus Bonus Unboxing!
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- Опубліковано 21 лип 2024
- Hi! Big thanks to www.pcbway.com for sponsoring this video!
We have a second go at fixing the so called tunnel vision problem on the LCD screen on this PowerBook 170. The same issue affects many early 90s Mac laptops with an active-matrix lcd display including the PowerBook 180. The most widely held theory is that moisture gets into the LCD panel creating a short in the liquid crystal, and baking the panel in an oven will drive that moisture out again. If your screen is going dark at the edges or corners, then you most likely are suffering from the same issue. Check out this video to find out how to fix, or at the least, make it less obvious.
We also open a package sent all the way from richsrandomretroreviews with some special upgrade goodies! Thanks Rich! Check out his channel for more retro Mac goodness / richsrandomretroreviews
Have a great day!
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Stock footage provided by peacezxp, downloaded from www.videvo.net
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In the summer time in Texas, I just use the car dashboard for baking electronics. On a nasty summer day, the temp quickly rises to somewhere between 85-95°C on the dashboard if the car is left in full sun. I measured 97°C surface temps on a hot 40°C day. You can also make very good baked potatoes on the dash. Just place it in a pot with a lid around lunch time and by dinner, it will be ready and delicious.
Top tip!
Awesome job Johann! I'm so pleased to see your hard work paid off! The display looks soooo much better. I'm also feeling very honoured that you spent so much time on your video unboxing and on the shout outs. I really appreciate it! Keep up the good work.
I didn’t think I spent enough time to shout out your channel! I am really very thankful you sent those goodies ☺️👍 hope you pick up a few subs/views.
Great result! Scary prospect though of baking it, I've seen a few fixes of resetting chips in the oven but am yet to try. Also nice to see Rich pop up
Yes it was a little nerve wracking , but you get to the point where you have nothing left to lose. Rich has a great channel! So thankful he sent me those goodies.
thanks for those tips. I have a PB170 that I need to repair, and it deffo started showing signs of this in the very edge of the corners. I keep putting it off because my PB180 works well so far.
Thanks for documenting this fix! Great video!
Thanks! Hopefully it’s useful for others with the same issue.
Nicely done! So glad this is a possible solution for this issue.
Me too! I have another machine exhibiting the same issue
Wow, that's amazing! Incredible video!
Why thank you kind sir! Yes it’s nice to have a positive result for once 😅
Thanks a lot ! verry helpful
You're welcome!
ummm... WOW what a great video. Your production quality is top notch! I can't wait to see what you produce next 👍
Hey thanks! I appreciate the encouragement ☺️
Love the fix! I've heard of people baking LCD's beforehand but you presented it in such a simple to understand way, it's removed any anxiety about trying this on a failing display.
I've also wondered how feasible it would be to go to a chinese LCD panel maker and say 'here - its a 1-bit LCD panel, these are the specs, make a new one that'll fit in the same physical dimensions, but using an LED backlight instead of CCFL'. No doubt it'd be expensive, but might be worth it for the community as a whole...
Thanks Kai! Yes I would definitely recommend people try this, it does seem a bit daunting at first, but if the display is already useless then there’s not much to lose.
I vote you go ahead with your remanufactured lcd panel idea! I’ll buy 2!
Loved this video! i own a very busted up sad looking 140, she may be headless but still chimes! I plan to 3D print a new rear housing at some stage, PCBway could also assist in making a 140 Display cable since those are equally as unobtainium
Hey, thanks for the comment! Sounds like your 140 is a challenging project, have fun!
That is A great Fix And A very nice Memory Up Grade
I’m very happy with the result! And the machine feels very snappy with 8mb of RAM
1:01 : that part was a bit scary :) hahaha. Great result, great cooking lesson :)
Practicing before I launch my cooking channel 😂
Thanks...that was very helpful. You do a nice job on your videos. I recently procured a 180 and on a warm, mid 80F day, it gets dark spots slowly on two corners. Just tried it today for 45 minutes (much cooler day) and no dark spots, though the cursor starts looking less black in the corners (more dark grayish) so I think it just takes longer. The only difference was that I took the corroded battery out.
It'll be a while before I have time to play with it (got some PiStorm projects in the queue) so I put it in a 2 gallon zip-lock and stuck a ton of silica packets in it to dry out any moisture (will update if that helps). I had a Mac IIsi for almost 10 years in the early 90's so wanted to have a real one for the next MARCHintosh. Need to find a video cable and internal SCSI-to-SD interface, then I'll be set :-/
Great comment, thanks for sharing your story.
Awesome results. I've seen some pretty tunnel-ey PowerBook screens and eager to try this out. Also really good tip on the re-assembly and lining up the crosses! Also currious to know if you saw a big performance increase with the additional 8mb? Thinking the HDD may be the next bottleneck.
To be perfectly honest (and hopefully help others) once you sit the screen back into the board, there’s almost no wiggle room, and the crosses didn’t quite line up, but they were all out an equal amount. The machine certainly felt snappier with the extra mb.
Beautiful B&O Pentas in the background there!!!
Good spotting! They’re a future project. Amp is blown and drivers need re-foaming.
@@TheBasementChannel Oh even better! I restore/repair B&O equipment to a very high level. Just finished a set of Pentas for a client. Let me know if you need anything or any information, I'd be more than happy to help! I'm in the US, btw. -Johnathan
@@Johnathan_Waters oh that’s superb! Can you reach out to my email in the channel about page?
I baked a screen on one of my Compaq LTE Lite systems. It had a really bad case of tunneling. I baked mine around 100C for 4 hours I believe. I have to watch my video to jog my memory. It’s a great time for follow up.
I used this method on my 180 and the tunnel vision problem is mostly gone. I had to bake it an extra six hours, though. I might try baking it even longer in hopes of getting rid of the problem completely. (There are still slightly dark areas that form in the upper left and lower left corners after a few minutes, but they don't get very dark.)
One thing I learned: Besides making sure to align the crosshairs well, make sure the contact strips along the edge of the LCD panel are clean and free of dust. I was getting vertical and horizontal lines on the display at first when I reassembled everything. It took me a while to figure out that it was because I'd gotten finger grease or dust on the contact strips. After I cleaned them off with alcohol, the screen looked perfect.
Great info, thanks for sharing your experience and advice. It helps create a useful knowledge base around fixing this issue.
Wonder how long the fix will last? Please keep us updated!
Good question! I’ll be sure to report back if it starts tunnelling again!
Cool. What about putting it in a food dryer? I have a big one.
I’d imagine it would achieve the same result. Give it a try and report back!
So is it moisture on the lcd? why does it manifests after a while of having it turned on? I wouldn't go above 85 degrees on the oven because the zebra strips are still attached to the panel itself and they can be destroyed. in any case, that did some good to the lcd and it looks way better!
The widely held theory is moisture has made its way into the liquid crystal of the display, shorting out the crystal when current is applied.
Excellent video, very reassuring. Is that Melbourne we see there? I’m in NZ :)
I have a PowerBook 170 here with terrible tunnelling - much worse than yours was - within five minutes of turning on, it’s completely black apart from a 5cm-diameter circle in the middle, which is perfect.
Can I just clarify whether you removed the zebra strips from the LCD please - before baking?
I actually wonder whether the zebra strips themselves would benefit from cleaning. Ispropyl alcohol usually temporarily swells silicone rubber and I wonder whether correct conductivity is restored just by cleaning and refitting. Or by heating? Is it possible that the LCD baking is a coincidence? :) certainly I’m going to try and fix this anyway thanks to your video - cheers
Hey Alex, not Melbourne, but Tasmania so pretty close!
Not sure what you mean by the zebra strips but everything I did was in the video.
There’s a range of theories out there as to the cause of the tunnel vision problem, but I personally subscribe to the moisture theory and have achieved great results with the baking method.
Good luck, hope you have success.
@@TheBasementChannel thanks!
By ‘zebra strips’, I mean the rubber contact strips that go between the LCD and the circuit board. I don’t think I could tell in the video whether you had left these on the glass during the baking, but I’ll look again
I think I took the rubber strips off but if I recall it was tricky to get them reattached. Sorry my memory is a bit hazy now, it’s over a year ago 😅
If you had to redo, would you reverse the order by cleaning first, baking second?
I don’t think so, as you have to handle the screen when baking. Perhaps clean it before and after? I cleaned before reassembly as it’s mainly fingerprint oils which don’t care about such low baking temps anyway.
Great, brave fix. I suppose if you hadn't tried this, eventually the screen would have become unusable anyway?
Yes, in fact it was borderline unusable as it was. I didn’t have anything to lose really.
Hello! How has the LCD held up since this fix?
Still the same, no more degradation so far. 👍
I never knew about those display alignment holes, thanks for the tip! would of been a good idea to clean those exposed contact pads also. BTW it wasn't the baking that fixed your display issue, it was the reseating of the display on the pads that get tarnished and lose conductivity. Leaving the laptop in a dry warm cupboard for 24 hours would have the same results of baking it in the oven.
Moisture isnt the cause as it would affect the whole display area and not only the corners. Combination of failing caps, poor connection to the LCD pad strips or even LCD adhesive polarizing film lifting at the corners where heat is actually causing this to happen!
Also, over time the display PCB starts to warp fom heat soak and the LCD strip pads can lose connection to the display. This is a slow gradual process. Run a hairdryer over the display with it powered on and see how quicky the tunnelling starts to appear. Then blow some cold air over the display and watch the tunnelling slowly disappear.
Placing shims under each of the corner display locking tabs to create a very tight clamping of the display should prove a more permanent fix.
I tried clamping the panel down tighter but it didn’t make any difference. I think my evidence speaks for itself but happy to be proven wrong once you upload your video demonstrating all of your fix ideas working.
@@TheBasementChannel Yes, but did you remove the panel first and then re-clamp it ? Sorry, I cant redo all my fixes but it is common knowledge the caps fail and polarizing film can cause this on many different laptop screens. Nothing to do with moisture, it's gradual heat creep either from the leaking caps or the polarizing film lifting from the display.
@@arnolduk123 my evidence and investigations would indicate it is neither of those things. If it was failing caps then re-seating the screen wouldn’t fix the issue without replacing the caps. If it was lifting polariser the effect would be visible immediately and not over time, also reseating wouldn’t fix this issue either. I’m sure there are other issues with screens cause by old caps, and I’m well aware of the vinegar syndrome caused by degrading glue in the polariser layer, but tunnel vision is very different to that. This video just forms part of a large body of evidence that points to moisture in the liquid crystal. We’ll have to agree to disagree.
@@TheBasementChannel Well without testing re-seating the display first then you would never know if that was what fixed it. The heat from the PCB, controller IC's and backlight would be enough to remove any moisture as they get quite hot. The oven baking cannot be established for cetarn if that fixed it or if it was moisture. Great video all the same and I do appreciate it BTW. But the issue that causes tunnel vision is still not establsihed.
Great job! Not only does the powerbook screen work but it also smells like last nights frozen pizza! Win Win!
Delicious!
Sorry if I missed this but why is it necessary to remove the LCD panel from the PCB before baking? At 85ºc I can't see how the PCB is any more likely to be damaged than the LCD panel and the LCD panel is not airtight and so any moisture should still evaporate with the PCB in place.
Can you clarify?
I felt more comfortable just baking the lcd panel which is mostly metal and glass and polariser film. The circuit board is probably fine to bake but I didn’t want to bake the backlight array and diffusion panels, which are sandwiched between the circuit board and lcd panel.
@@TheBasementChannel thanks. I had not thought about the polarising films. That could get damaged with heat.
Moisture isnt the cause as it would affect the whole display area and not only the corners. Combination of failing caps, poor connection to the LCD pad strips and failing LCD adhesive polarizing film lifting at the corners. Heat is actually causing this to happen!
@arnoldrimmer4833 the evidence would suggest otherwise
@@TheBasementChannel You would not know if simply removing the display and re-seating it improved the display. I assume that you did not try that first ?
Why bake it? I put mine in a waterproof container with some silica gel bags for 24 hours and my results were just as good. I didn't even need to take the LCD off the circuit board.
Would love to see a video demonstrating this working. I’ve heard conflicting stories about this proposed method.
It’s been a year. Has the fix held up? Thinking about trying it on my PowerBook 180.
This is how it looked 11 months on. No change from when it was baked. tinkerdifferent.com/threads/tunnel-vision-on-pb170.778/page-7
@@TheBasementChannel cool. 30 min is a little short mine starts acting up around 45 but I’ll give it a shot! Looks like you left the rubber zebra strips on as well. You’d probly have to tear them off to remove. They’re glued on on the Macintosh portable. I imaging that’s the same on these…
@@TheBasementChannel whew, I just did mine. Baked for 8 hours at 180. Put it back and a bunch of dead vertical lines 😬 tried retightening and nothing. Loosened them all up and shifted it as far left towards the backlight as I could to get the crosses to line up as close as I could. Impossible to get it aligned. And then retightened and all good. I’ve been through hell with the Mac Portable lcd displayed haveing the same missing lines issues so I though I was cursed. 30 min timer set to check the results 🤞
@sideburn awesome, thanks heaps for reporting back with your experience, it’s really valuable for the fixit community! Let us know if the tunnel vision is fixed.
@@TheBasementChannel going on two hours and just a tiny bit of darkness in the top corners. It’s been like that for a while and not growing. Amazing simple fix. Fits right in there with the retrobrite phenomenon
How does this look now that it has been 11 months?
Great question, I’ll fire it up and see.
@@TheBasementChannel any luck?
@@stephenh.gerstacker2807 thanks for reminding me! I’ll try and get to it on the weekend, darn work!
@@stephenh.gerstacker2807 ok so I had some time after work today. It appears exactly the same as when the panel was first baked. I’ve put some photos and details here: tinkerdifferent.com/threads/tunnel-vision-on-pb170.778/page-7
@@TheBasementChannel Awesome! Thank you! Looks like I'll be baking my 170 some time soon.
The music during dialogue has an annoying ticking sound -= noticed that on a few videos
*checks the vicinity for giant clocks 👀