oscillating problem with backlight or inverter

[bpoindexter]

I have a Toshiba Satellite S75-B laptop, running Windows 10 Home. With a period of about one to two seconds, the screen oscillates between a perfect image and a "washed out", but still somewhat visible image. Is it possible to know for sure from these symptoms whether my problem is hardware vs. software? And, if hardware, what component or connection link I should focus on?

 

[webworkings]

Try this...

1. Turn the laptop off (not sleep or hibernate but off).
2. Connect an external monitor to the laptop.
3. Turn on the external monitor.
4. Turn on the laptop.

NOTE: You may have to press an "external monitor" button. Could be the f4 button or a button with two monitors on it, for the external monitor to work.

If you can see fine on the external monitor, then your attached display, or the ribbon cable that connects it, are your problem.

If you can't see on the external monitor at all, or the problem occurs on the external monitor as well, then it is probably the graphics card/GPU that is the problem, which may require the motherboard be replaced.

 

[bpoindexter]

Try this...

1. Turn the laptop off (not sleep or hibernate but off).
2. Connect an external monitor to the laptop.
3. Turn on the external monitor.
4. Turn on the laptop.

NOTE: You may have to press an "external monitor" button. Could be the f4 button or a button with two monitors on it, for the external monitor to work.

If you can see fine on the external monitor, then your attached display, or the ribbon cable that connects it, are your problem.

If you can't see on the external monitor at all, or the problem occurs on the external monitor as well, then it is probably the graphics card/GPU that is the problem, which may require the motherboard be replaced.

 

[bpoindexter]

Thanks very much, webworkings!
Yes, I neglected to mention that I already knew that the image is fine on an external monitor. Would you guess that it is either a connection issue or a defective inverter (i.e., as opposed to a defective screen)? Is there any way to differentiate between an inverter flaw and screen flaw before opening it up? Perhaps some diagnostic software that you have had success with?

 

[webworkings]

It is not likely the inverter as that would lead more toward darkening than the issue you describe. It could, however, be the cable that connects the display. A loose or damaged connection could cause that.

 

[bpoindexter]

It is not likely the inverter as that would lead more toward darkening than the issue you describe. It could, however, be the cable that connects the display. A loose or damaged connection could cause that.

================================================
I appreciate the insight very much, webworkings.
Once I get to the bottom of this, I will post all the findings I collect in hopes it will help somebody else down the line.
Keep up the great service of sharing your knowledge/experience with the community!

Best regards,
bpoindexter

 

[webworkings]

Thanks. Do let us know, always good to know what happens.