marce002
Badcaps Veteran
Last Activity: Yesterday, 05:17 AM
Joined: 05-30-2018
Location: Buenos Aires
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MSI GE75 8sf 16p71 mother
Hello this 8sf 16p71 is dead so new mother arrived. it is 16p71 ver 1.0 same as old one but 9sf instead of 8sf... all connectors match except old has trackpad 10 lines and new only 8, but seems to be 2 debug lines dif, and nothing trivial....PROBLEM IS NO VIDEO NOT TURNING ON .. tried with power sw, 20vol, one ram, and video connected , no beep no video only usb present, 5v and 3.3v are ok...... no video hdmi... mother was tested ok by ebay seller (good reputation)... fans start after maybe 1 minute, but now they are disconnected so dont know. mother looks like new. no VCORE is present...please... -
this is the shorted part. looks like mosfet.... found led drivers from burned house applianced leds , but theyare not suitable for this, they are buck led drivers 8 pins. any help will be muuuch apreciated.thksLast edited by marce002; 11-16-2024, 04:24 PM. -
Replacement for LED DIMMER chip
Hello I have a led lamp with 3 TP8005S chips. one is shorted but cant find a replace part around.
.. is it easy to replace with another option? it is just on /off led lamp for scooter... low beam and high beam are working just fine...Last edited by marce002; 11-16-2024, 04:19 PM. -
Thanks a lot T J!! it was a 320 ohm resistor close to the opto, whose value was wrong and turned out to be burned in the hidden bottom side. tks now output is 12.8V the endLeave a comment:
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hi the values from GND pin 5 with out load (blue) and with lights (green) on are:... and just in case the diode im VD1 and the other one on left V1 are: VD1= MBR20100CT and V1= HY1710Last edited by marce002; 11-11-2024, 06:13 AM.Leave a comment:
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sorry, the blob is ok, just me replacing a zener but was not shorted and the other blob on + is a wire + used with my power supply to test also ok.
i will recheck and report back Volts, because ic gnd was not my reference, used wire conecror gnd, my fault.thksLeave a comment:
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that is the first i check... it still is 19.34v with lights on and all turned on... besides the audio center and BT device does not work due to overvolt... what else to try?
note the 3 resistors 1kohm near the transformer seems to be quite hot to touch, but maybe normal...Leave a comment:
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72v to 12v 10A output is high 19.6v
hello, this is from electric moto scooter... something happened and blown an onboard fuse in the converter box..replaced it and also replaced a bulged cap 100v 100uf ... now works but get 19v in the output instead of 12V...
what else to check please!! this is the board:... -
As i stated before i have 0.249v in br/ctl... so maybe should desolder it and test if shorted ?
Now i realize that seems to be D8 shorted.Last edited by marce002; 10-17-2024, 06:23 AM.Leave a comment:
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nope, the source power is from 7550 regulator and his output to the FP5139 is exactly 5V, so the problem is in the "load side", what else can I test...? or maybe fp5139cis fried?. thks again!...Last edited by marce002; 10-16-2024, 05:20 PM.Leave a comment:
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thks ... it seems low v ..(tested with output enabled 5v 3A , display showing 0.67v 2.92A no load!!) and in 5139: 0.369v in vcc pin and 0.249v in br/ctl... will check who gives vcc to ir right?Last edited by marce002; 10-16-2024, 03:06 PM.Leave a comment:
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Changed the mosfet, and problem still there. sadLeave a comment:
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Boost ZK 4KX low output damaged?
Hi
This device is a common buck boost 0v to 30v...
It was working good now shows close to 0V output whatever Volt I set. The unit is powered from good amps 12v server power supply. I took appart and shows no phisical damage... mosfet looks fine ..what can i try? see pics:
thks in advance!!... -
5n60c as first post picturedLeave a comment:
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ok ... now on case that i would like to make 12v fixed output .. what resistor would you change?Leave a comment:
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it is 3A 42v output. i though someone would direct me to replace some resistor in some pin for a POT to make it variable output, but seems it is not so easy.Leave a comment:
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whatever can be done will be ok, thanks stj!!...
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Can you suggest me how to variable output this 42v fixed
Hello
I have this board working fine designed to 42v fixed output using lm324n chip and i really need to make adjustable output (ideal if Vol and Current with 2 pots but at least only Vol).... i was trying to do it with datasheet and several diagrams but could not
the pins 1 2 and 3 are unconnected so it is using only 3 op amps in the chip.... How do you think I can mod it?
or any hint for an schematic similar.. thks in advance...
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