PQB11 GIVES 0.00 with everything probably faulty one . PQB12 BLACK PROBE pin 2 pin 2 pin 4 red probe pin 5 pin 4 pin 5. Pin 2 plus pin 5 =0.485mohms. Pin 2 plus pin 4 =0.485 mohms. Pin 4 and pin 5= sometimes it's giving 0 sometimes 0.484 mohms probably because my probe not like needle test probe.looks like pqb11 is fault how do I order a replacement.
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Can you give links for both PQB11 AND PQB12 to replace both of them to be on the safe sideComment
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PB11 and PB12 are very common to motherboard style mosfets that are based on the BQ series battery charger chips. Each can be replaced by many others.
Both are N-channel type mosfets.
Replacement parts must be:
1) 5 * 6 mm in body size
2) N-channel type
3) able to support 30v of switching voltage between source/drain
4) Vgs of 20v
Attached are the datasheets for these parts.
PQB11:
PQB12:
(similar specs but the body size is 3 * 3 mm)
Suggestions:
1) If you are not in a rush, order these parts from Aliexpress (China) but you will have to wait till they return from the CNY holidays and of course the delays in shipping.
2) Consider to source locally from your local electronics stores
3) Remove from a donor dead motherboard - contact your local computer stores for old Dell / HP motherboards
4) Contact your local cell phone repair shop who may have access to the same parts and also the service to replace these SMD mosfets.
5) Order from Digikey / Mouser / Arrow / RS ElectronicsComment
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Can you send the schematic diagram for this motherboard please. I found this laptop in my house how do I check it has both mosfetsComment
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So I ended up giving the laptop to the repair shop and he ordered the parts and will be fixing them. In the mean time I got a new laptop but I have the ssd of old laptop which has Windows and all my data I booted into the new ssd and configured windows but now I want to boot into my old ssd and format the new ssd and then transfer all my old data into the new ssd but it give me this INACCESSIBLE BOOT_DEVICEComment
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Hello,
I have different sort of those little BGA chips (step down DC-DC, power management battery, …) I replaced 10 on differents mobile devices (no schematics) but I noticed often they can be dead but never shorted. I see some signs : burn marks, resistance drop by comparison with good board (40 KOhms to 1 KOhms for example)… but not easy to be sure of the diagnose. Because I can't access on all tracks (balls) with the meter.
Sometime, I know only after replacing chips.
Do you have tips for diagnose please ?
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I have 50 surface pro 7's. This is for my company that I am in charge of fixing. So many units are not working, meaning the touch isn't with new screen. I get the error precise touch device error 10 in device manager. I flash bios, tried updated drivers but to no avail...Is this a bios issue? -
Hello to everyone ,
So far most of the repairs that i've been doing was novice, i would say. With a lot of help from you gents.
Now ,i got in my hands a lab-supply. So , i have a laptop in my hands that doesn't turn on , remains dead , but at the same time there is no short circuit in the main line (as i think off).
I know that i should put 1v-2v to ground (black wire) and red wire to close the circuit to a specific place after the DC-IN port.
Now the question is, where do you place it most of the time , i mean in which specific place after the power... -
My AIO computer has suddenly stopped working. When I plug it in, it draws 300ma and fluctuates between 270ma-310ma and then settles. No picture on screen and no power light, also no response from power button (no fluctuation on power draw) however the CPU gets warm. Pulled the BIOS battery and put a new one in but it does the same. Used a multimeter to check for shorts but the 3.3v and 5v are working fine. Some of the caps are beeping near the CPU but I think this might be normal.
Can anyone help? -
Hi everyone 😀,
I'm here today to ask for help with repairing the motherboard of a Lenovo Legion Y540 17IRH.
To give you some context, I'm passionate about computer repair so much so that I've invested in a lot of tools and started practicing on dead and old hardware. I've been learning how to solder and desolder components, mostly focusing on phone repairs.
Recently, I bought a broken Lenovo Legion Y540 17IRH for just €150, and there are two main reasons why I made this purchase:- I already own the exact same model, but its plastic chassis is badly damaged.
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