Can't get 3.3 or 5v because 19v can't get past second power fet (PQ101). I have 19 volts on one side of the fet but nothing on the other. It reads fine in diode mode. Gate voltage is high though (19v), so is that why it's not opening? That would make sense except that gate voltage on PQ100 is also 19v but voltage passes through that fet just fine. Aren't both gates powered by the same source?
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Re: Compal LA-8241P
do you have dc bench power supply?
check gate circuit below fets on the diagram. otherwise lift gate pin of pq101Last edited by fddizon; 10-27-2014, 02:33 AM. -
Re: Compal LA-8241P
Yes, I have a power supply, used it with 1.5v and 2a to legs 5-8 of PQ101 and voltage stayed steady and amps were .07, is that considered a short? What are the components of the gate circuit, still learning how to read these schematics? Looks like PR105, PQ105a and b, PQ103 and 104 and PR103Comment
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Re: Compal LA-8241P
check for acin, dcin, acok signals on PU100. P-channel mosfets are switched with negative voltage.Comment
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Re: Compal LA-8241P
PU100 pin 13 ac ok,see if that is ok
sorry did not see the above postLast edited by cyberhack; 10-27-2014, 06:14 AM.Comment
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Re: Compal LA-8241P
check both sides of pr119Comment
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Re: Compal LA-8241P
I now have purchased a good board that powers up just fine for comparison measurement purposes. To backtrack a bit, PQ101 on the good board measures no resistance in diode mode either way, PQ103 shows 19v on all 3 legs, and PQ104 shows 19,0,0. PQ101 on the problem board measures like a normal fet in diode mode, open in 1 direction and about .5v in the other. PQ103 shows 19v on 2 of the 3 pins, PQ104 shows 0,0 and 5v. So the gate circuit being a mess is affecting how PQ101 acts, correct?Comment
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Re: Compal LA-8241P
chceck pins of pq105Comment
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Re: Compal LA-8241P
check voltage of pins of Pr118 and PQ109Comment
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Re: Compal LA-8241P
Have nothing on pins of PQ109, cant find PR118, very little on this board is marked. None of the resistors in the area of PQ109 measure 47k resistance so there's no telling which one it could be. Did locate what I believe to be PR109 (remember, no DCIN to PU100) and with my power supply put 2A to each end of resistor. PU100 gets warm with probe on one side of resistor, so removed PU100. Pad of PU100 still warm with 2A put to PR109. So chip itself not short? Next put the 2A to trace #22 and it shows short too. PC111 short?Comment
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Re: Compal LA-8241P
remove pc111 and u see. when removed u must see voltage on sides of pr109Comment
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Re: Compal LA-8241P
Still don't know where PR109 or PC111 is. However, found shorted cap on other side of board with power supply and now have 19v on both sides of large resistor (the one below PU100 with the circled 19) which I thought was PR109. It isn't because I still don't have 19v to pin 22 of chip. Do have 3v to pin 2 though, so the large resistor must be PR113? Next short is on one side of upper resistor to right of PU100 (the one marked 4R7)Attached FilesComment
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Re: Compal LA-8241P
on pin 22 of chip u see capacitor that must be pc111, check for short and if u have remove itComment
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Re: Compal LA-8241P
PR113 should be small in size. The big resistor must be PR109. You should see by traces which cap is connected to pin 22 of PU100.Comment
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Re: Compal LA-8241P
board not ON 3.3 v in power sw ok . when i testing SIR, +3VALWP AND +5VALWP not come out (but when connect adaptor it comes for a second and goes 0v. on PU200 ic +3VLP pin no-8 ,VL pin no. 17 & 2VREF_6182 pin no.3,4 & 14 ok . so please what fault in this board .charger ic or PWR-3VALWP/5VALWP sectionfaultLast edited by atkari.p; 02-24-2018, 06:24 AM.Comment
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I am having some trouble with troubleshooting a Asus X532FL rev 2.0 motherboard, which does not power on. So at the first MOSFET, I am getting 19V at the drain, and then 3.2V on both gate and source (compared with ground). Of course, the 2nd MOSFET's source will have 3.2v at source.
First MOSFET is a QM3056M6 and 2nd MOSFET is a QM0930M3
I already checked first MOSFET and source and gate are not shorted (drain with source not shorted either). Also I have 1.7V at the LDO rail (measured at the keyboard connector, as the power button is on the keyboard).
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Hello!
This is my first post for help, and I am quite newer to board repair, so bear with me.
I have this board here (LA-E671P), with no power, and doesn't charge. No lights come on when plugged in.
After visual inspection of the board, U22 is obviously blown up. This is the for backlight, and there is no shorts present after removing the chip and replacing.
There is 3 USB C ports to power this board, USB 1 gives 20V, while 2 and 3 only give 5V.
My observations using USB 1 at 20V (0.075A draw on Ammeter, slowly drops from 0.136A)... -
Hi, I recently got an XPS 9550 that won't charge due to the "Unknown Charger" PSID issue.
I replaced PQ100 to no change, PR102 reads at 33 ohms, PR101 reads at 2.2k. When PQ100 is removed, the source pad reads at 3.3v, the gate reads at 5v, and the drain at 0v. When it is in place, both drain and source read at 1.4v, and gate still reads at 5v. PD100 is blown clean off and as such reads basically open.
I don't know what exactly to do from here, except maybe investigate PQ101. -
Just did this on my 2021 13" MBP M1. Dust-Gate design flaw still present. Depending on cleanliness of the operation environment (often eating while using MB is probably the worst). Periodic cleaning is probably warranted.
Note this is quite challenging effort. One misstep will damage the LCD flex and render it useless. So take it to someone more experienced if uncertain.
https://www.ifixit.com/Guide/MacBook...leaning/17792010-09-2024, 10:10 AM -
Hello, maybe someone have Compal GH51M LA-K862P 1A boardview?
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