That's fairly easy to fix although it's going to require dismantling the screen and replacing some capacitors - I've seen that failure mode a couple of times now on the Toshiba UA0392P01 inverter boards. If the electrolytic capacitors wear out or have leaked, the inverter starts making a high pitched noise when running.
The Toshibas from around 95ish all use the same UA0392P01 inverter, I've seen them on the Satellite 4xxCDT, 200CDS, 110CT and T2130CS so far.

The two capacitors that are marked in red in these pictures are the problem. I can't remember which of the two was the problem so I think it's best to replace both:

Here's an example inverter to point out the capacitor that needs changing:
C3: 10uf 35v. Around 6mm high with 5mm diameter. 105c rating.

There might be some leaked electrolyte to clean up but there's not much to leak from these 😀
I think I ended up putting one of the caps on sideways to get it to fit, but there's some room to work with since the screen housing is quite roomy.

edit for 2024: Capacitor C1 is a polymer capacitor and does not need replacement. Specifications if the capacitor needs replacing because of damage / corrosion from C3:
C1: Sanyo 10SL33M - 33uf 10v. Around 6mm high with 6.5mm diameter. 105c rating.

Thermalwrong wrote on 2022-07-14, 22:13:

That's fairly easy to fix although it's going to require dismantling the screen and replacing some capacitors - I've seen that f […]
Show full quote

That's fairly easy to fix although it's going to require dismantling the screen and replacing some capacitors - I've seen that failure mode a couple of times now on the Toshiba UA0392P01 inverter boards. If the electrolytic capacitors wear out or have leaked, the inverter starts making a high pitched noise when running.
The Toshibas from around 95ish all use the same UA0392P01 inverter, I've seen them on the Satellite 4xxCDT, 200CDS, 110CT and T2130CS so far.

The two capacitors that are marked in red in these pictures are the problem. I can't remember which of the two was the problem so I think it's best to replace both:

Toshiba-Inverter-3.jpgToshiba-Inverter-1.jpgToshiba-Inverter-2.jpg

Here's an example inverter to point out the two capacitors that need changing:
C1: Sanyo 10SL33M - 33uf 10v. Around 6mm high with 6.5mm diameter. 105c rating.
C3: 10uf 35v. Around 6mm high with 5mm diameter. 105c rating.

There might be some leaked electrolyte to clean up but there's not much to leak from these 😀
I think I ended up putting one of the caps on sideways to get it to fit, but there's some room to work with since the screen housing is quite roomy.

That's exactly same inverter board and as I know now the 563J capacitor (C4) is shorted (near backlight connector) can this be replaced with regular capacitor ? What parameters are of this thing? Or it's cause of that 2 capacitors that you listed ?
I'll give you a photo of mine inverter board and if you could you'll give me a edited photo with capacitors marked that will need replace. Also today when I tried to power on the laptop o internal display it instantly powered off after screen was supposed to come on.

Hey there, good timing! I was just checking out the laptop I last fixed the inverter on, to find that the inverter turned on for a few seconds, then off/really dim and there was the fish smell of electrolyte 😁

I just found out that the electrolyte wasn't cleaned up fully on my inverter. It had got under the big inductor and had discoloured the inverter connector - that cleans up pretty well by soaking / spraying with IPA then brushing a paper towel onto it to remove the electrolyte. It had got under the MLCC capacitor C22 (1uF) & C11 (10nF) on the back:

All cleaned up and replaced with a modern 1uF MLCC, so tiny in comparison:

---------------------------

Does the laptop start up without the inverter fitted? With most of these old screens, you can test without the inverter and shine a torch into the screen to read it.

I just checked the C4 - 563j capacitor on my board and it measured just about 1 ohm exactly. That's probably not the issue if it was running and making a squealing sound.

I've circled the cap that was bad on my most recently repaired board, the 35v 10uf capacitor. I squished a 100v 10uf capacitor into that space and it's a pretty good fit overall.

Remove the capacitor C3 (has an arrow) and then clean up with isopropyl alcohol (IPA) a few times.

Check around the components on the front & back of yours to see if any are shorted like the capacitors, electrolyte is conductive and can be under the SMD components. An ultrasonic should clean that up but I don't have one...

-----------------
Lastly, the Satellite 200 / 400 series are severely prone to failure due to battery leakage from the standby / RTC batteries that sit above the mainboard. Make sure those are removed and I recommend pulling out the whole motherboard and look at the back of the board to see if corrosion is there too. Just clean it gently with IPA to get the worst of it off. Use vinegar sparingly. I've killed a couple of semi-working boards by cleaning a bit too vigorously 🙁

I have a Satellite 430CDS with the same issue.
I think i will fix the capacitors in a near future. But by the meantime, i found that changing the screen brightness in the bios fixed the noise.
Its under the power management section. Something like "Power saving : custom" then "Brightness : low" (or backlight : low)
Of course, this also reduce the backlight intensity. But if you're not using the laptop outside with the sun reflection, this should be ok.

Hello thanks for reply!
yesterday i checked my inverter and i saw that a big SMD cap on bottom of the inverter was a bit dark in one area also the laptop (screen and that areas) smell like a fried fish 😀
and around the capasitor that you marked the is a little hole in pcb that looks like fried or something. I don't know much about electronics .
and yes laptop start's up without inverter board, also my C4 cap is like near 1OHM but i don't know. what do next after removing C3 ? Can i get it back soldered and after all cleaning ? or it will run just fine without that capacitor ???
EDIT: it start's with monitor only

acl wrote on 2022-07-29, 08:21:

I have a Satellite 430CDS with the same issue. I think i will fix the capacitors in a near future. But by the meantime, i found […]
Show full quote

I have a Satellite 430CDS with the same issue.
I think i will fix the capacitors in a near future. But by the meantime, i found that changing the screen brightness in the bios fixed the noise.
Its under the power management section. Something like "Power saving : custom" then "Brightness : low" (or backlight : low)
Of course, this also reduce the backlight intensity. But if you're not using the laptop outside with the sun reflection, this should be ok.

IMG_20211205_010811.jpg

i also found out that thing 😁 just need to press FN + F2 keys
but now it's not mine problem because laptop does not start with inverter board connected it just makes a 0,1 sec noise and all laptop shuts off with power LED red blinking.

That's great that it still starts up without the inverter.

Can you get a picture of the burned bit?
It sounds like the electrolyte caused something to short out, which is just what happened to mine yesterday - although on mine it didn't fully short, just went dim / unusable CCFL brightness.
Your inverter might work again if the short is cleared from the components, but if the PCB burned then that will also need cleaning back since burned PCB can be conductive too.

Possibly it would be easier to source a replacement UA0392P01, they're common for such an old part since the laptops they were in more often failed due to battery damage, or a smashed screen. It's in everything from the T21xx series, Satellite 100/110, 200/210, 400/410/420/430 laptops, apparently along with the Tecra 700CS/700CT too.

As an alternative, you could go down the LED backlight upgrade route - I just did that for a laptop I broke the CCFL tube in and with some extra circuitry to make it work, it can even control the brightness. Sadly I don't think 11.3" LED strips are as common or cheap as the 10.4" backlight I replaced. What I did there was actually unnecessarily complex, you can get an LED backlight kit and just fix the brightness at one level. It should need something to go from 5v (Toshiba inverter power) to the 12v (LED driver board) power too.

Thanks for quick reply and now I'm not home but as soon as I will get home I'll get picture of that things and if you have a discord you can text me: C\KAROL_2#5120
EDIT: here you got that things that you needed

The last photos aren't the best but yeah that's it.

Thermalwrong wrote on 2022-07-29, 13:56:

That's great that it still starts up without the inverter. […]
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That's great that it still starts up without the inverter.

Can you get a picture of the burned bit?
It sounds like the electrolyte caused something to short out, which is just what happened to mine yesterday - although on mine it didn't fully short, just went dim / unusable CCFL brightness.
Your inverter might work again if the short is cleared from the components, but if the PCB burned then that will also need cleaning back since burned PCB can be conductive too.

Possibly it would be easier to source a replacement UA0392P01, they're common for such an old part since the laptops they were in more often failed due to battery damage, or a smashed screen. It's in everything from the T21xx series, Satellite 100/110, 200/210, 400/410/420/430 laptops, apparently along with the Tecra 700CS/700CT too.

As an alternative, you could go down the LED backlight upgrade route - I just did that for a laptop I broke the CCFL tube in and with some extra circuitry to make it work, it can even control the brightness. Sadly I don't think 11.3" LED strips are as common or cheap as the 10.4" backlight I replaced. What I did there was actually unnecessarily complex, you can get an LED backlight kit and just fix the brightness at one level. It should need something to go from 5v (Toshiba inverter power) to the 12v (LED driver board) power too.

Hello I found on OLX ( some kind of polish ebay there are also allegro ) cheap replacement UA0392P01 that is tested and comes from satellite 410cdt (I think from tft screen but I dunno) and yup the shipping costs like 20PLN (it's like that cause it's pocztex shipping) and only inverter costs like 30PLN but I'm gonna negotiate with seller. Anyways thanks for help ! 😀

Great, that should be the quickest way to get it back to working 😀
I hope it's all trouble free for you from here.

Thermalwrong wrote on 2022-08-08, 00:18:

Great, that should be the quickest way to get it back to working 😀
I hope it's all trouble free for you from here.

Thanks for reply
I have an question will inverter from TFT screen work normally in DSTN screen?
Also waiting to it arrive to my house I'm using this beautiful laptop on crt with is working very good.

Yep, the TFT inverter is the same as the DSTN one.

Apart from the LCD and cable harness, the only difference is that the DSTN one has a separate extra board that has the contrast wheel, that plugs into the LCD cable rather than the inverter.

Thermalwrong wrote on 2022-08-14, 15:07:

Yep, the TFT inverter is the same as the DSTN one.

Apart from the LCD and cable harness, the only difference is that the DSTN one has a separate extra board that has the contrast wheel, that plugs into the LCD cable rather than the inverter.

Ohh God good that they are compatible I thought that there will be some voltages different or smth i dunno but anyways thanks for all help specs of the caps ( maybe I will in late future replace them ) and see you next time 😉
Bye bye

Hi, I have a problem with a Satellite like this. I recap the inverter because it sounded noisy but the problem wasn't fixed. Yesterday I replaced the inverter and the contrast potentiometer with a new one but the problem still exist and black screen on the monitor. The lights under the LCD swicthes on but black screed is displayed.
If I conncet and externeal VGA monitor, the external monitor works good and run windows 95 correctly but if I switch the laptop LCD respond always with a black screed.
I should change the LCD?
Thanks everybody.

Here a picture

hi all

i am also interested in fixing the old laptops of 90's. Right now i have Satelite Pro Toshiba 400CDT, however its borken !!!. When i start with the power cable plugged in (Plug sign green and Battery sign Orange), after some time, the BIOS screen apperas however only one side (diagnoally) of the screen is visible (text appears) and the other side is darker !!!!. What might be the issue ? How can i fix the display issue Please ? Isuue with Display or Inverter ??!!??!! i can toggle between BIOS options ...But no idea what to do with this ?!?!?!!?1. thank you, regards

the Screen looks like this

Keekan_kk wrote on 2024-10-30, 21:55:

the Screen looks like this […]
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the Screen looks like this

That does suggest a fault with the backlight circuit mostly. Try replacing the capacitor C3 on the inverter board to see if that helps, if it doesn't then perhaps you could see if the backlight works properly when powered with the inverter from another laptop, or a CCFL tester.
I used a light-blue-box one like this "12V CCFL Lamp Inverter Tester For LCD TV Laptop Screen Backlight Repairing Test" which has the larger CCFL connector that the 400CDT uses.