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- g´day! I have a samsung 22" tv monitor to fix. power supply model bn44-00505A. some stuff blown up on the primary, according to research something typical on this model. secondary seems ok. writings on the board say in outputs a5v (standby), b5v (switched) both on the lower 3 diodes on the picture, vamp and b13v (12.8v, both are the linked at the connector that goes to the main board) my question is, are both the upper diodes for 13v? I believe so but wanted to make sure before injecting voltage there to test. I injected 5v on the lower side and standby circuit is working fine
Fontana
Member
Last Activity: 01-21-2025, 12:03 PM
Joined: 05-04-2017
Location: Curitiba
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BN44-00505A dead. Need to know voltages on output diodes (Samsung T22B300EW)
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Re: 71R-H14BW6-T830, clock stops when shutdown
replaced bios and ec rom chips. replaced crystal again. no luck... -
Re: 71R-H14BW6-T830, clock stops when shutdown
I have, but since I have a working board I'll try replacing the bios chip altogether. will try another crystal as well for peace of mind.
but if that doesnt fix the problem what can it be? the cpu?Leave a comment:
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Re: 71R-H14BW6-T830, clock stops when shutdown
2.8V
more than the meter can measure, but this is also the case in a known good board that I have. in diode mode .9V drop...Leave a comment:
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Re: 71R-H14BW6-T830, clock stops when shutdown
I have no way to measure it, but it should be fine. I removed it from a board of the same exact same model which problem wasnt related. unless I broke it when replacing but I doubt it. I used heat from bottom of the board to remove it and soldered it back with unleaded....Leave a comment:
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Re: 71R-H14BW6-T830, clock stops when shutdown
DC plugged, machine turned off, 2.87V (3.08V on pin2)
DC off, 2.85V (2.98V on pin1)
Sorry, forgot to mention I had tested the diode already.
Also, SRTC_RST# after R407 is 2.8V...Leave a comment:
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71R-H14BW6-T830, clock stops when shutdown
Hi!
Funny problem. I have a board, model 71r-h14bw6-t830, it's a shuttle board used commonly on a lot of cheap laptops/AIOs.
The clock (RTC) is not working when the machine is turned off. Doesn't matter if it is connected to dc power or not. When the PC is powered on, the clock works fine.
I tried replacing Y6 and Y7 (picture below), but it doesn't seem to be an oscillator problem.
I don't have the exact schematic for this board, but I'll provide one that is similar (a variation of the same board).
Any suggestions?
OBS: when the pc is off,...Last edited by Fontana; 09-28-2022, 10:04 AM. -
Re: HP Envy 17, LA-C991P, Burned components
thanks for the help. the mosfets are the same packages. I'll order them and scrape the board a bit more and replace them. I think with the appropriate mosfets the issue will be solved....Leave a comment:
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Re: HP Envy 17, LA-C991P, Burned components
they go straight to the charger, yes. Seems to be a very similar circuit. Mind telling me what board your picture is from?
this one I'm working is a i7 6700HQ + gtx950, powerbrick is 150w
also they seem to be the same package as the ones I need.
If it isn't too much to ask, care to give me a quick explanation on how would I go about choosing a replacement? what specs in the datasheet would I need to look for? drain current and power dissipation?
I noticed the specs of the 2 mosfets differ a lot, despite...Last edited by Fontana; 09-23-2022, 01:58 PM.Leave a comment:
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Re: HP Envy 17, LA-C991P, Burned components
They are the 'main' mosfets right out of the dcin.
the charger ic is an intersil ISL95520...Last edited by Fontana; 09-23-2022, 01:31 PM.Leave a comment:
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HP Envy 17, LA-C991P, Burned components
does anyone have a hp envy 17 board? model is LA-C991P. I need to know what mosfet is PQB03 and PQB01 (the main 19V mosfets). couldnt find schematics. the one on the board I'm working was completely charred, the whole area was carbonized. I replaced it a couple months back but it came back with it almost desoldered from the board. so I think maybe it is too weak for the job or maybe I didnt scrape enough the burned traces when I first did the job... -
Re: New Members - please post your introductions here
Hello!
I'm from Brazil but soon to be moving to europe.
Been doing repairs for a long time, hope to continue doing there.Leave a comment:
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