ASUS FX505DT

[Paulo11]

Hi members. Maybe somebody can help my find out if my laptop is totaly toast or not. I buy it recently with no boot fault and I thought I can repair it, but after several hours on it I think CPU or GPU is toast.
So laptop is :
Make: ASUS
Model: FX505DT-BQ143
Symptoms: No boot, black screen(even through HDMI), keyboard light on, battery is charging, capslock didnt work. Every rail is present 19V(20,2 from charger), 5V, 3,3V, 2,5V, 1,8V. Even CPU is powering up a shows 1,1V, but every 4second falt to 0 and then back to 1,1V- looping. Hence i thought just the bios is scrambled, so I tried several version, with no luck. But with 1 version it didnt loop, just stays on.
I didnt try voltage on GPU, because everything is under heatsink and I don´t want to short something by probing under heatsink. Can somebody write me what resistance can have that GPU and CPU on main input coils ? My CPU have about 1,2Ohm, and GPU about 0,6Ohm - and this is too low I think. But I thought even with bad dedicated GPU(If this is that case) can laptop boot on integrated GPU. Or if I have bad GPU can I somehow force to boot and work on integrated GPU ?
Thank you in advance for any help.

[mcplslg123]

The resistance for CPU/GPU is fine .

[myth77]

Looping is fine if you removed bios battery, the system is trying to read the bios and adjust some seetings, and that probably means that cpu is ok also. I dont know if this model has integrated gpu. Try this, after laptop makes several boots try pressing caps lock key on keyboard...if you see light goes on and off then your cpu is fine and you have a problem on gpu area.

[Paulo11]

Looping is fine if you removed bios battery, the system is trying to read the bios and adjust some seetings, and that probably means that cpu is ok also. I dont know if this model has integrated gpu. Try this, after laptop makes several boots try pressing caps lock key on keyboard...if you see light goes on and off then your cpu is fine and you have a problem on gpu area.

Looping would be good if it doesn´t loop forever I left it looping for about 30-40 minutes and nothing happens exept CPU(maybe GPU too, it has one heatsink) warming up and fans regularly spins for couple seconds- thermal managing work.
Have somebody any ideas how I shoud look/measure/try ?

[Paulo11]

The resistance for CPU/GPU is fine .

I didnt find good resistance walues anywhere. So thank you for your verification

[jasko_jacker]

This notebook has a Ryzen 5 3550H which has an integrated video card, the Radeon Vega 8. The PCH seems to me to be internal to the CPU so if the problems are there there is little that can be done.

[Paulo11]

Ok, so little update:
Laptop is finally working.
Solution: DIY "reflow" of CPU and GPU with hot air.
Maybe there was some bad/cracked joints and that "reflow" melted it together, so it work again.
Thank you all for your time

[jasko_jacker]

I hope it is a permanent repair, often it is not a problem of lack of contact between the balls and the motherboard but an internal problem with the chip that could recur. However, as long as it works...