Sunday, June 12, 2011

Up Late

Up late trying to make sure everything works, buttons, answering questions that may have been missed. And printing postal addresses. After that last hectic week...


  1. dear, i have a question.
    i try to test a mosfet but in the true way i read 450 (on diode mode) in the wrong way(reverse probes) i read 1230...way??
    consider that i have a digital multimeter???thanks

  2. hello Mr. Mayo,
    i have a problem with a hp dv2000,
    it's sort of a weird but let me try to explain it to you.

    the laptop wont boot running on the batery alone, (black screen, all blue lights on), but if i plug de dc power and let it on for about 10 seconds and restart the laptop; it will boot.

    it may probably be the nvidia chipset but the laptop boot-up every time doing the procedure described above.

    thanks in advance. any help would be really apreciated.

    Pd. sorry for my english...

  3. Good day sir, Please i have a little problem which i know very well that you can solve it. The laptop is (HP Compaq NX7300) the problem it has is from the power jack. it was sent for a repair and the power jack on the circuit was damage. Now can't locate the negative line on the board because is broken off. I have the picture of the point and i was think on how i can send it to you. please can you kindly send me a temporary email to so that i can send you the pictures of the motherboard and the point where the power jack is sitting. Thanks in advance.

  4. Fransanos: Perhaps the meter did not reach infinity. Also test between GATE and DRAIN. sometimes the zener between the circuit shorts too. But 450 in one direction should be good and high/infinity in the other appears to be ok. Also check another MOSFET to see if infinity is reached. It may be the meter not reaching max resistance, or is limited.

    Anthony: No, your problem seems to be in the Mosfet that triggers the charge circuit, MAX8734 or even the CMOS battery. Also test MOSFETS between DC-In and the battery first (before replacing MAX8734).

    IMO: You caught me at a bad time and may not be able to answer emails immediately. But will send an address. You could also find a NEG line on the battery in area and make a temporary path connection to that to test.

  5. dear, thank you very very much. So if in the "Wrong" way i read a 300 or 400 the mosfet is short? thanks.Is ok if i touch both pin with probe, es. pin 2-3 with red 6-7 black??

  6. thanks a lot! Mr. Mayo.

    i'll do as you have suggested and let you know the results.

  7. Hello, i have to replace one i think mosfet transistor on Acer Aspire 5315,it is is located under keyboard, and it has 8 legs- 4468 BA7V6N, my question is where can i buy one, i am from Europe, Croatia, thanks

  8. any idea how long the kit is going to take to turn up to the uk, have paid quite a while ago now

  9. Still havent received the DVD i Payed since day 1 please contact me
    info at

  10. hey Doc. so ive spent the last few minutes on how i can inform u how VERY greatful i am of your blog, without actually using up a single minute of your time. with no solution in mind, im relying on hopes that ur the record holder for speed reading, and im not that much of a bug. hahah. also how releived i feel after spending countless hours researching laptop repairs guids and "real" tech responses, just to hear, "well you should just buy a new mobo". long story short, im a new, VERY new, repair tech in central cali, thats built a QUICK reputation for being a highly skilled micro tech. which is still hard to wrap my head around coming from no school, teaching or training of any kind. but also a reputation that has been questioned do to time missmanagement (by me). reading through your blogs has answered several questions ive had. Thanx so much and youll be hearing from me soon.

  11. Hey doc, first I'm so sorry if you've covered this already, but I havnt had time to read through your entire achieves. I got a dell xps m1530 that was randomly shutting down. I was explaining overheating and CPU problems is probably the cause, when the video went out in front of both us. Confirming my theory. I reflowed the unit and got it Bak together to find it stuck in sleep mode. With nothing but the fan, no ram, cmos, or even CPU, right when I plug in ax adapter the unit powers on, but in sleep mode, enabling me to du anything. I have removed one component at a time all the way down to bare. One thing I havnt done is a manual cmos/bios jump cuz I havnt been able to find the mobo codes. Any help would b great. Thanx

  12. hello mr Mayo
    which IC is responsible for detecting battery in inspiron 1540 dell??


I cannot repair laptops for you via the internet, I can only answer questions related to posts. This is because I have not had experience on every motherboard that is out there. Bear with me.

If you do need it repaired. Contact me for quote (US/CDN Only)

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