How to test Mosfet driver RT9619a VRM section on motherboard not generating Vcore voltage pls help PWM signal from RT8802a is showing 2.4v .
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I was working on this machine yesterday and I now going to use an incandescent lights instead of a fuses to figure out what the issue is with it blowing control voltage rail but this not the only issue the coolant pump failed the meager test as well as the main motor as well this motor has 12 motor wire leads instead of the normal 9 wires
This metal lathe has a weird motor setup it has a soft start motor with a “Y” and a delta type of motor winding setup and it is not done in the motor pucker head enclosure it is with four different contactors wired in a configuration I have not... -
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... -
Hello
I have power adaptor(220V/input, 12V 1.2A/output) which has symptom of fluctuating output DC voltage between 11.5V-12.2V.
So I opened its plastic case and when switched it on, I heard constant tik tik sound from inside its PCB.
I measured DC voltage between negative and positive pin of the largest capacitor(400v 10uf) and it was measured contant 300V.
I also measured ESR value of all capacitors and I noticed that one of capacitor(KMG 16v 470uf), which located in the secondary side, have high ESR value(10 ohm),So I replaced it with same specification NXH capacitor.... -
Hello
I have a big problem and that is that in some cases when repairing active pfc power supplies I cannot work with a test lamp. I can only get help with 5 volts standby and for starting and starting I have to work without a lamp and this way there is a possibility of parts exploding and other parts being added.
Sometimes with a multimeter test the problems can be reduced to some extent, but I had several cases that had to be tested on and online and recently two varistors exploded. They had terrible resistance because the power supplies were over 800 watts.
Is there a way... -
Hello.
GPU came in, green lines. Spent lots of time using to get the Mats / mods drive working (found on youtube).
Found issue with a RAM block
Replaced, green lines gone.
Trying to test again, assuming getting the false positive. Originally had over 1K on a single bank. Now getting tosses low between banks.
Used a good card to test and same results low errors 32+.
I am just search for some form of command to do a full test on the GPU.
I just ran the mats command with my good GPU and passed after roughly 40 min.
The repaired one, ran...
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