Re: Need help to understand this circuit
My bad, i got it mixed up. That other thread isn't updated.
So the current state is:
I replaced the LLC IC, both mosfets, some resistors and both optocouplers
-Now i get 5,2 - 5,9V fluctuating at the output.
-Main filter cap is sitting at 330V
-VCC for the PFC IC is fluctuating 11~13,5V (not turning on)
-FB pin sitting at around 0.6V
On the secondary side, i checked the bigger electrolytic capacitors and the rectifiers.
I noticed that while measuring the resistances...
Fr3shGy
Member
Last Activity: 11-26-2023, 02:15 AM
Joined: 03-25-2015
Location: Austin, TX
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Last edited by Fr3shGy; 06-19-2023, 10:35 PM. -
Re: Need help to understand this circuit
I have a problem, not with that exact board but a fairly similar one (BN44-00786A), just couldn't find the exact schematic.
Both mosfets went out and took the IC with em. I replaced both FET's the IC and a couple of resistors.
After that the IC would not switch on not even in burst mode. So i checked the FB line and found out that both optocouplers PC801S and PC802S were shorted.
Replaced both opto's and now the IC is sitting in burst mode and the Output (A13V) gives me 5,2 - 5,9V fluctuating....Last edited by Fr3shGy; 06-19-2023, 08:22 PM.Leave a comment:
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Re: Need help to understand this circuit
Thank you for clarification.
1. If anyone of those PCM's had a problem on the cold side, the IC would always stay in burst mode?
2. When the IC operates in burst mode, output voltages would always fluctuate?...Leave a comment:
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Re: Need help to understand this circuit
That one of them is for the feedback circuit makes sense, the second one could be for over current protection, maybe?... but the third one?
the sample circuit of icm801s only shows 1 optocoupler for the feedback
...
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Need help to understand this circuit
Hi, i am having a hard time understanding this circuit.
"The optocoupler isolates the primary from the secondary side."
1. Does that mean that whenever there is an issue, lets say a big short on the primary side, the secondary won't get damaged?
2. Why does this circuit has 3 optocouplers?... -
BN44-00786A no power/no standby
I already posted a month ago about broken components on my BN44-00786A PSU that i replaced.
Took me ages to receive all the missing parts.
I replaced the purple marked components in picture 1 mainly the LO and HO line components, the components at the VW line, both mosfets and the IC.
I attached a picture with all the measurements i get currently.
1.VCC is sitting around 1.8kohms and puts out 11,28V
2.LO output gives me flat 0V therefore i get no voltage at the gate of the mosfet.
3.The...Last edited by Fr3shGy; 05-30-2023, 02:19 AM.Leave a comment:
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Re: Samsung U32D970 PSU blown up (Identifying Parts)
thank you for helping me with this. i only had a 10mf capacitor laying around but i ordered a full set of them with lower values. for now i replaced the cap with the 10mf one.
I am getting weird readings. the second mosfet does not turn on (i marked some readings in the picture).
I probably need to replace C820 aswell because the 11V does not pass through. as soon as i get the replacement caps i will make a more detailed overview of the readings i get....Leave a comment:
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Re: Samsung U32D970 PSU blown up (Identifying Parts)
so after waiting ages for the parts, they finally all arrived.
currently replacing the 6A01 and the resistors. i found out that the capacitor CM804 gives me no reading inside nor outside the circuit and needs to be replaced.
Does someone has the value of CM804?...Last edited by Fr3shGy; 04-13-2023, 05:12 AM.Leave a comment:
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Re: looking for fuji 6A01 IC replacement
Hm, weird ...but that´s the link^^...Last edited by Fr3shGy; 03-27-2023, 06:48 PM.Leave a comment:
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looking for fuji 6A01 IC replacement
Hi, i am looking for a replacement IC. Currently i got this IC:
6A01 IC datasheet ( )
i found a different version a 6A21. Is this the same IC with a different manufacturer date? -
Re: Samsung U32D970 PSU blown up (Identifying Parts)
Thank you all for the help. I am currently in the process of replacing and ordering the new components.
I am going to replace both mosfets as lotas has suggested. the broken ones are:
Fairchild FDPF18N50T
[URL="https://www.mouser.com/datasheet/2/149/FDPF18N50T-1008232.pdf"]https://www.mouser.com/datasheet/2/149/FDPF18N50T-1008232.pdf[/URL]
Can i replace them with mosfets which have a lower "continuous drain current" rating like APT9N70's? Or are they likely to...Last edited by Fr3shGy; 03-26-2023, 04:02 AM.Leave a comment:
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Re: Samsung U32D970 PSU blown up (Identifying Parts)
Yes both traces got damage. i am going to change every part on each trace.
i am not certain what values these resistors have.Leave a comment:
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Samsung U32D970 PSU blown up (Identifying Parts)
Hi, my U32D970 PSU (BN44-00786A) has blown up. It went out with a loud bang.
One of the N-Channel Mosfets (OM802C) caused a short and fried the trace and its components connecting to one of the pins of the 6A01 IC.
I need help to identify 2 SMD resistors which lost their markings
highlighted in picture 3 (RM812 and RM808).
Maybe someone can help me identify them, has a schematic or can give me some advice. would be much appreciated.
6A01 IC datasheet ( [URL="https://www.fujielectric.com/company/tech/pdf/59-04/FER-59-4-245-2013.pdf"]https://www.fujielectric.com/company/tech/pdf/59-04/FER-59-4-245-2013.pdf[/URL]...Last edited by Fr3shGy; 03-25-2023, 02:03 AM. -
Re: looking for GIGABYTE RX 6800 XT BoardView (.tvw)
thank you very much...Leave a comment:
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looking for GIGABYTE RX 6800 XT BoardView (.tvw)
Hi, i am looking for the .tvw file. They have it over on the vlab forums but i can not access it.
Does anyone has the file or can grab it from over there?
appreciate it.
GIGABYTE AORUS RX 6800 XT MASTER 16G BoardView (.tvw)
GV-R68XTAORUS M-16GD
Rev: 02B -
Lenovo Thinkpad Tablet 10 assembly [gone Wrong/gone Bad, click]
Hello,
I need some advice. i disassembled my lenovo tablet 10 to replace the battery. now i can't figure out where the smartcard reader cable connects to?
I can't find the connector on the board? see picture below.
Help is highly appreciated....Last edited by Fr3shGy; 08-29-2021, 01:59 PM. -
Re: ASUS PG27V No Power, blown part help to identify
makes perfect sense. basicly i now go ahead and check the Vin voltage and replace it with a similar one.
thank you very muchLeave a comment:
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Re: ASUS PG27V No Power, blown part help to identify
Thank you for helping. I took a picture of the LDO its either 57199 or S7199.
I looked at the blown LOD and yes you are right it seems like this one has a diffrent number on it ... it says "25A9" or "2549"
Its very hard to see. I can't find any datasheet for either "25A9 or "2549"
...
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ASUS PG27V No Power, blown part help to identify
Hi,
My ASUS PG27V monitor died a couple of days ago. No LED no power at all.
It has an external 19V power supply.
I took it apart and it looks like there is a MOSFET SOT23? / Diode? blown. The board is a 4H.3Q601.A00.
Below the blown part, there is the same or similar Mosfet with the lable "57199", but i can't find a datasheet to see if it is a shottky diode or an N-channel Mosfet.
I need help to identify or figure out what part i can replace it with. I have some SOT23 Fets laying around.... -
Re: LightmaXX LED PAR64 wont power on
Sorry i mean pins.
So basicly if i touch one of these pins with my multimeter the ticking slows down and the DC voltage goes from ~5V up to 24V.
this happens with following parts:
R15, R16, D4, U2, R13, R17, D2, U1, D (The Mosfet), C12, C13, C14, C15, C16
And it starts if i heat up that section of the PS.
What does that mean?
I checked the resistance of the DC Lines it goes from 400 ohms up to 600 ohms then my multimeter shows overload?Last edited by Fr3shGy; 11-16-2016, 12:32 PM.Leave a comment:
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