Hi guys,
I have a dead NAS QNAP TS-453Be which I'm trying to fix. The board is tagged as QY47 REV 1.6 20008-A02112-HT-10-RS
I've not found any schematic or boardview, so I'm flying blind. I'm analyzing it as I would have done with any other PC or laptop motherboard and I'm using as a reference the boardview from an AsRock J3455-ITX board I found.
I started checking all buck converters and they're all running except one that looks it's going to the CPU. The buck is composed of a RT3601EA and mosfets H8324 and H8334. I've meassured the mosfets and they look good. Also the controller, both resistances and voltages and looks good also, it has all input voltages and even the enable pin active and VR_READY is set to 3v but there's no PWM output at all.
There's other buck using the exact same components that is outputting 0.9v (assuming also for the CPU). I've meassured it and it's 90% the same except from the SET pins which have small differences. The DVID pins for both controllers are plain 1.05v, no data on it at all, moreover, there's no clock. Is the failing buck required to have DVID communication? Not sure what comes first...
I'm assuming the working buck is the VNN which comes first according to the CPU specification found at https://www.intel.com/content/www/us...asheet-v1.html so the not starting one should be VCC_VCGI
I'm assuming the CPU is not shorted. From the inductors to ground I have 50 Ohms for the stopped buck and 72 Ohm for the 0.9v buck.
Here's a picture just in case it helps:
The not starting one is marked in red color. The blue one is the 0.9v and the yellow one is the RAM (correctly outputting 1.35v).
Not sure how to continue from here. I think I may have to check communication signals between CPU and EC but it's an IT8528E and I've not been able to find the datasheet for it, and boardview from the AsRock board uses other EC.
Any help is appreciated. Thanks
** To the admins, as this hardware is really similar to a PC board I posted this here. If it's the incorrect forum, please move it where it should be . Thanks
I have a dead NAS QNAP TS-453Be which I'm trying to fix. The board is tagged as QY47 REV 1.6 20008-A02112-HT-10-RS
I've not found any schematic or boardview, so I'm flying blind. I'm analyzing it as I would have done with any other PC or laptop motherboard and I'm using as a reference the boardview from an AsRock J3455-ITX board I found.
I started checking all buck converters and they're all running except one that looks it's going to the CPU. The buck is composed of a RT3601EA and mosfets H8324 and H8334. I've meassured the mosfets and they look good. Also the controller, both resistances and voltages and looks good also, it has all input voltages and even the enable pin active and VR_READY is set to 3v but there's no PWM output at all.
There's other buck using the exact same components that is outputting 0.9v (assuming also for the CPU). I've meassured it and it's 90% the same except from the SET pins which have small differences. The DVID pins for both controllers are plain 1.05v, no data on it at all, moreover, there's no clock. Is the failing buck required to have DVID communication? Not sure what comes first...
I'm assuming the working buck is the VNN which comes first according to the CPU specification found at https://www.intel.com/content/www/us...asheet-v1.html so the not starting one should be VCC_VCGI
I'm assuming the CPU is not shorted. From the inductors to ground I have 50 Ohms for the stopped buck and 72 Ohm for the 0.9v buck.
Here's a picture just in case it helps:
The not starting one is marked in red color. The blue one is the 0.9v and the yellow one is the RAM (correctly outputting 1.35v).
Not sure how to continue from here. I think I may have to check communication signals between CPU and EC but it's an IT8528E and I've not been able to find the datasheet for it, and boardview from the AsRock board uses other EC.
Any help is appreciated. Thanks
** To the admins, as this hardware is really similar to a PC board I posted this here. If it's the incorrect forum, please move it where it should be . Thanks
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