Hi good day to all, I have a problem with this unit DAZAAMB16E0 REV E from PQ22 pin 1 I only have 3v , im not good at board that doesnt have schematic and this problem is not common to me. Hope someone can help me .
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Re: No Power output voltage 3v from VIN
Hi
messure the resistance from pq22 pin1 to ground -
Re: No Power output voltage 3v from VIN
https://drive.google.com/file/d/1NsM...lNLY-gOgi/view
Isn't this the board?Comment
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Re: No Power output voltage 3v from VIN
Pq22 is a deplition type mosfet ,n channel
So it is always on until there is some short in line
First we should have either 25 voltage in normal case at source and in case some issue it should go to full zero.
Measure voltage on gate
Verify voltage on all pins of charging ic and check pq22 for shortComment
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Re: No Power output voltage 3v from VIN
I think it's an error in the symbol. It doesn't make sense to use depletion mode MOSFET here, and they are also never used in practice, it's always enhancement mode. It needs 25V on its gate to turn on.OpenBoardView — https://github.com/OpenBoardView/OpenBoardViewComment
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Re: No Power output voltage 3v from VIN
I already change the pq 22 and the charger IC , I already burned 3x of ic and in the 4th it work bad soldering tehcnique , thanks to all and the scheamtic great helpComment
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Re: No Power output voltage 3v from VIN
Update it wont power againComment
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Re: No Power output voltage 3v from VIN
measure Voltage on pin 1/2/3/4/5/6/24/28 of PU5. Replace PC136 with exact same value.Comment
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Re: No Power output voltage 3v from VIN
Not very convinced with your readings. Seems IC pins are not soldered properly. Look under a microscope or atleast a magnifying glass.Comment
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Re: No Power output voltage 3v from VIN
PR168(866K) & PR3(137K) forms the divider circuit for ACDET pin. As per voltage divider formula you shoud get 2.60V (19x137/866+137). You are measuring 1V at acdet pin, so either of these two resistors is likely bad. Measure both of them preferably out of circuit.Comment
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Re: No Power output voltage 3v from VIN
If you read functional diagram BQ24780SRUYR you will notice even at acdet greater than 0.6 voltage your REGN 6v should generate. Check pin 24 value again at charging ic.
What is voltage on pc122Comment
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Hi all!
I'm trying to troubleshoot a Microsoft Surface Pro (5th gen) model 1796 that won't power on. Motherboard model is M1007506-015. My priority is retrieving data, but the SSD is integrated so it looks like if I can't repair it it'll need to go to a data recovery company. I've done a little basic board repair before, but nothing this advanced until now. So please forgive my ignorance in advance. 😅
I found the boardview for this laptop in the forums here, and am able to open it on my PC with FlexBV.
https://www.badcaps.net/forum/troubl...-hardware-devi... -
Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming... -
Hello, I have an asus Z97-A motherboard and it doesn't start which was working properly before, the problem isn't related by ram, ram slots or psu (I changed all and nothing work), the exact problem is when you switch it on , it starts and after 1 seconds (no boot or display picture) it's off and then on cycle continuously until you power it off from psu also it's responding to the power switch for turning it off if you keep pressing it 3 or 4 seconds (power button pin has 3.3v) , also when you start it with eatx 12v socket connected this is happening (power cycle also all voltages are resetting... -
Hello everybody I try to fix thi power supply, I have voltage in bridge rectifier, and also in the large capacitor , so I thought the problem was in the pfc but then I found all mosfet ok(tested out of the circuit so I just moved on in the low voltage and here I found a short of one of the diode rectifier. I'll replaced it already but it's completely dead, I mean any stanby voltage and the other voltage is not present. I don't have oscilloscope to understand if the chip work how can I test it? Thank you for the help 🙏 -
Hi guys
This power supply is from an FM Radio transmitter
It takes an input of 28V and should output some lower voltage. When I first looked at it I found that there is a zener diode D3 directly across the V out to ground and it was short circuit.
I removed the Zener, there are no markings to determine it's correct value, and I don't know what Wattage it should be either, plus it broke in half. I took a photo comparing it to a 1N914 signal diode and a smaller zener which I have (which I think are 0.5W but I am not sure) and also a resistor so maybe someone can...
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