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Powerbook 2400c inverter
Posted by: jlindsay26 on 2023-06-21 14:08:18
Working on a powerbook 2400c I thought it had a bad backlight so I replace the bulb but still no backlight bought a tester for the bulb and confirm it's working so I supect it's the inverter board so I figured I ask a few questions. in the attach picture does anyone know if F1 is a fuse? It look like it marked 1.25A ? 73 I checked and it doesn't have continuity. Second question second picture on transformer should I have conitunity between the two right soldered connection. lastly open to any suggestion on things to check/testing. Thanks in advance.
Posted by: macuserman on 2023-06-21 14:13:09
Following in case you figure this out, I've got several of these that could use repair. Seems to be a failure-prone part.
Posted by: jlindsay26 on 2023-06-21 14:26:32
I think your right since I have two and both aren't working. I'm almost wondering if I could wire-in a replacement inverter or I guess I could permanently attach the tester to the powerbook.
Posted by: MacUp72 on 2023-06-21 23:56:10
I think to narrow problems down quicker one should have one working machine and swap part for part.
its enerving..like the 3400s
Posted by: Garrett B on 2023-07-19 07:31:06
Working on a powerbook 2400c I thought it had a bad backlight so I replace the bulb but still no backlight bought a tester for the bulb and confirm it's working so I supect it's the inverter board so I figured I ask a few questions. in the attach picture does anyone know if F1 is a fuse? It look like it marked 1.25A ? 73 I checked and it doesn't have continuity. Second question second picture on transformer should I have conitunity between the two right soldered connection. lastly open to any suggestion on things to check/testing. Thanks in advance.
Where did you find a replacement bulb? Trying to track down similar issues on mine.
Posted by: macuserman on 2023-07-19 07:37:53
Where did you find a replacement bulb? Trying to track down similar issues on mine.
Parts for these are pretty much unobtanium, you have to just grab them when they come up which is rarely, I have a pretty large stash of parts for these machines I'll be liquidating at some point when I have time to go through and build out the best units.
Posted by: jlindsay26 on 2023-07-19 19:16:42
Where did you find a replacement bulb? Trying to track down similar issues on mine.
eBay 10.4 inch 2mm diameter came from china worked fine get the one without the connector just leads and reuse the from from the old bulb.
Posted by: jlindsay26 on 2023-07-19 19:19:42
I’ll mention replacing the bulb isn’t too difficult but I would suggest getting a tester if your not positive the bulb is bad
Posted by: Garrett B on 2023-07-20 05:47:34
I’ll mention replacing the bulb isn’t too difficult but I would suggest getting a tester if your not positive the bulb is bad
Thank you for the info - super helpful. I did verify the bulb on mine is bad. Has a really pronounced red tint to it, indicating it's on its way out.

I take it the controller board has to be moved out of place to access the bulb? Trying to avoid messing with this panel as much as I can due to how rare they seem to be.

LCD (2).jpg
Posted by: jlindsay26 on 2023-07-20 06:33:00
Thank you for the info - super helpful. I did verify the bulb on mine is bad. Has a really pronounced red tint to it, indicating it's on its way out.

I take it the controller board has to be moved out of place to access the bulb? Trying to avoid messing with this panel as much as I can due to how rare they seem to be.

View attachment 59581
I'll take a few picture and post them later today I bought bulbs from this seller tvrepairledtester listed as follows I have extras if you want a couple send me a PM I'll be happy to send you two if you cover the shipping.

220mm*2mm CCFL Backlight Lamps for 10.4'' Laptop LCD Monitor Brand New​
Posted by: jlindsay26 on 2023-07-20 14:39:34
Here are some pictures of removing the backlight remove the three circled screws this should allow you to remove the metal frame around the front of the screen
Posted by: jlindsay26 on 2023-07-20 14:42:44
next remove these screws and you can pull back the controller board there's and edge connector under the arrow so you'll need to pry that loose
Posted by: jlindsay26 on 2023-07-20 14:44:38
peel the controller board back pull the back light out remove the light and solder new bulb in
Posted by: 3lectr1cPPC on 2023-07-20 16:27:46
Removed, sorry
Posted by: Powerbook27364 on 2023-07-22 06:02:27
I just got a 2400c/240 and it’s display is smashed. The backlight doesn’t turn on through and brightness controls don’t change it either. I was wondering could this be a bad inverter or backlight? Is there any way to know which without a bulb tester?
Posted by: jlindsay26 on 2023-07-22 08:14:56
I just got a 2400c/240 and its display is smashed. The backlight doesn’t turn on through and brightness controls don’t change it either. I was wondering could this be a bad inverter or backlight? Is there any way to know which without a bulb tester?
Not PowerBook specific but I seen videos where people hook up backlights to a working laptop’s inverter to test. The tester I got was pretty cheap on Amazon currently $10 but you need to use you own 12volt power supply.
Posted by: Powerbook27364 on 2023-07-22 09:18:23
I don’t think I have any other inverters that would work. Voltage is 0v going to the backlight. I need to try to get a display and inverter now it seems which is going to be difficult.
Posted by: jlindsay26 on 2023-07-22 15:19:38
I don’t think I have any other inverters that would work. Voltage is 0v going to the backlight. I need to try to get a display and inverter now it seems which is going to be difficult.
It does it seems like this is a point of failure for this model and finding parts is difficult. I’m in the same boat.
Posted by: Powerbook27364 on 2023-07-22 15:21:41
Would there be any way to use a new inverter or wire direct power to the backlight? I’m not sure what else the inverter does but I Might just do that if it only powers the backlight
Posted by: jlindsay26 on 2023-07-22 15:47:49
here's a link that describes the inverter https://www.techwalla.com/articles/what-is-an-lcd-inverter
Found this link, figure I'll try the tests they recommended https://jestineyong.com/test-lcd-inverter-transformer/
not sure if there would be enough space but you might be able to squezze a second inverter in an open portion of the screen housing or maybe switch to LEDs haven't really explored that option, but it might be the only option given rarity of these laptops
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