I have a laptop that just keeps restarting ~ every second and get no vcore voltage. The laptop does have one those NEC/TOKEN capacitors and i have a good feeling that is the problem. However i also think it can be the gpu and want to try a reflow on it. so the question is: Can a gpu failure prevent me from getting any vcore voltage? Or is it just the NEC/TOKEN cap?
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Re: no vcore if gpu failure?
Definitely replace NEC/Tokin before going near the GPU.Dell E7450 | i5-5300U | 16GB DDR3 | 256GB SSD -
Re: no vcore if gpu failure?
cpu capacitors , vcore control , southbridge .Comment
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Re: no vcore if gpu failure?
very often faulty capacitor causes restarting problem and if there is token then try cure it up first.Comment
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I will just preface all this by saying that I have a fairly technical background but have never attempted SMD electronics diagnostics and repair before, I really like the idea and want to learn.
I have a MacBook Pro late 2016 that died maybe four years ago. Over the course of 30 seconds, it got slower and stuttered, until it froze for a second and died. No click from the trackpad anymore, nothing. I started getting interested in electronics repair and decided to give it a shot, so I opened it, removed the battery (one cell was puffy), took out the motherboard and experimented with...10-15-2025, 01:53 AM -
Hi, Would appreciate some help.
I have an Apple Late 2013 15" A1398 MacBook Pro with Logic Board 820-3662.
Get charger light but no fan spin or chime. No liquid damage.
Found PPBUS and VCORE both shorted to ground. Other rails were ok.
Removed VCORE MOSFETS U7310, U7320 and U7330. Found U7330 was in fact shorted.
With the 3 MOSFETS removed, get PPBUS and fan spin. VCORE is still hard shorted to ground (0 ohms).
Attempted voltage insertion on VCORE to locate short using bench supply set at 1.0 VDC and 4.95 Amps (max current for my... -
Hi, have a HP workstation Z2 Mini 4G for repair with CPU vcore missing.
The resistance at the output of CPU vcore coils, is less than one ohm so I think CPU could be damaged, but no mosfet are damaged.
It mounts an i7 8th gen, and have only i5 7th gen for test, but I think it is not compatible.
Without CPU in the socket there is no short, but there is no vcore voltag, and it emits a beep like no detecting ram.
The controller chip for cpu vcore is a MP2949A, and has no enable voltage at pin 37.
I wonder which circuit generates this enable... -
Hello, this is my first post, English is not my native language but I hope you understand me. I recently got a 580 that didn't turn on the typical short mosfet, as I didn't know exactly which one was short, I unsoldered them until I got the bad one out, I was able to remove the short and identify the bad mosfet, the gpu gives video again! but it has a problem that completely turns off vcore at random times or if I try to put a load on the gpu vcore drops to 0 I don't have much idea why because I don't know much about sapphire, any advice on where I could start looking or what problem it could... -
Hi,
My laptop went dead and after checking ,the main 19 volt power rail was shorted. After some checks i could identify that a high side vcore mosfet was shorted.
I replaced the mosfet and now the white powerled is present , fans start spinning but capslock shows the famous 5 long and 3 short code.
I checked the vcore voltages after replacement and i get for all 1.01 V so means for me that the driver is still working of the replaced shorted mosfet. On the Nvidia i measure around 0.8 V after the mosfets.
I did voltage injection on the cpu with 0.7V and i have a current...
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