Hello everyone,
I have a pretty bad and hard to recognizing problem with Wistron PV-01 mobo from Probook 4520s.
The mobo powerups without CPU for maybe 1 second and then shutdowns. With CPU powerups for 15 seconds and then shutdown without getting POST screen or something. And then it startups again after 5 seconds and same thing is happening. The consumption was around 35 W from the adapter.
The adapter is OK, on battery is the same thing.
The bios battery is showing 3.04 V - which is OK.
There's no overheating anywhere, with or without heatsink, the same things is happening.
All voltages and power schematics are checked. All of the voltages are appering while it's on and there's no problem with any of them. All of the mosfets are checked. There's no short anywhere.
I have checked it with two CPUs, many RAMs and what so ever.
The last symptom of the laptop before failure was screen flickering and then suddenly restart.
Even when it shutoffs, there is always 19.34V on DCBATTOUT /the main power bus/.
So, there's not problem with power rails anywhere. The problem is more complicated and I can't get it.
I have a pretty bad and hard to recognizing problem with Wistron PV-01 mobo from Probook 4520s.
The mobo powerups without CPU for maybe 1 second and then shutdowns. With CPU powerups for 15 seconds and then shutdown without getting POST screen or something. And then it startups again after 5 seconds and same thing is happening. The consumption was around 35 W from the adapter.
The adapter is OK, on battery is the same thing.
The bios battery is showing 3.04 V - which is OK.
There's no overheating anywhere, with or without heatsink, the same things is happening.
All voltages and power schematics are checked. All of the voltages are appering while it's on and there's no problem with any of them. All of the mosfets are checked. There's no short anywhere.
I have checked it with two CPUs, many RAMs and what so ever.
The last symptom of the laptop before failure was screen flickering and then suddenly restart.
Even when it shutoffs, there is always 19.34V on DCBATTOUT /the main power bus/.
So, there's not problem with power rails anywhere. The problem is more complicated and I can't get it.
