Toshiba Laptop Won't Power Up

[Appletax]

Guy has a Toshiba Satellite S75-B7218 laptop that is dead.

Using original + other AC adapter there's 0 lights.

Using new Onn 90W universal adapter the power button lights up, but the indicator lights are off.

All I can think of is either bad DC jack or bad mobo.

How does one decide which it is?

Take the DC jack out and test it with a multimeter? Luckily, it is not soldered to the mobo.

I bet smarter people can do stuff to the mobo to diagnose it as bad or good.

 

[Diggs]

Zero lights doesn't say much. Several of my old HP laptops go dark after they are fully charged. If it has a good battery and doesn't boot then I tend to say it's the motherboard.

 

[nlinecomputers]

Take the DC jack out and test it with a multimeter?

Yes. it’s a wire. A simple continuity check will tell you if you have a break in the wire. But honestly if you don’t see physical damage or burns then its fine. It’s a piece of wire not complex integrated circuits.

 

[britechguy]

No snark intended, but have you advised this client that it might be better to get a new machine and have you transfer his stuff over?

Toshiba's been out of the market for several years now and this model dates from around 2014 and can't run Windows 11 (if he wanted to upgrade).

Diagnostic time for something like this can easily eat up half the cost of a very, very nice new machine. And given its suspected age, he's due.

 

[Fred Claus]

Laptops are a pain to work on. I'd advise the purchase of a new one. You could spend all that time fixing the port, only to find it's the motherboard that's the issue.

 

[Larry Sabo]

All I can think of is either bad DC jack or bad mobo.

How does one decide which it is?

Measure the voltage out of the adapter plug with it disconnected from the laptop, to ensure the adapter outputs 19v. Then measure the voltage at the DC connector on the motherboard with power connected to the DC jack. If you get 19v on the MB, the DC jack and its cable are good. If you don't, it could be a bad jack/cable, or a bad MB.

To verify it's not the jack/cable, measure the resistance between the jack input and the connector at the end of the cable. You may have to insert a matching universal adapter plug that's not connected to the adapter itself, and measure between its input pins and the cable end, since it's sometimes impossible to probe inside the DC jack.

If you have continuity between the DC jack input and the cable end connector, the jack and cable are good. If so and you don't have 19v on the MB then it's a MB fault. Even if you do have 19v on the MB's DC connector, there could be faults on the MB that prevent the charge/power LED or other LEDs from lighting, e.g., due to missing voltages from auxilliary supplies (3.3, 5v, etc.).