Diagnosing EAX64905001

[litec systems]

Re: Diagnosing EAX64905001

1) ok
2 ok, and I've unfortunately never learned electronics, so i don't know what's every component purpose ( BUT I'd love to hear & learn & understand more every day 😀
3. Sorry, my bad I've got confused from other cap
The c102 has a writing of "331 1kv" and it was a blue one
4. I've haven't the old cap, as I've threw it.. But I've did wrote down his markings and replace with a new one, and no, I'm not talking about c102, I've asked generally ( specifically for an LG HIFI SYSTEM that i have ) if I can use a blue one instead of the brown cap. Below are some pictures that I've got on my phone from the HIFI circuit, let me know if i u need more photos)
5. My bad I've got confused from other cap. You right.
6. Ok, but the shipping from these websites are pretty expensive.. So I'll probably try my luck on eBay, and hope for the best, and even if it's not original, hope it'll work well& safe...

I've referenced to the c102 & that HIFI system, sorry for not being clear enough and so confusing 🙏

[budm]

Re: Diagnosing EAX64905001

Your post #14
"Basically the mosfet + its 1kv capacitor + a 2w resistor + the fuse blown up ( known issue on this set).
So which cap is that one then?

[litec systems]

Re: Diagnosing EAX64905001

Your post #14
"Basically the mosfet + its 1kv capacitor + a 2w resistor + the fuse blown up ( known issue on this set).
So which cap is that one then?

Hi
Its the c102 of the MOSFET ( on the TV PSU)
It's a blue 1kv 331

[budm]

Re: Diagnosing EAX64905001

So it tested shorted, correct and you replaced it when you replace the MOSFET and the resistor as shown in your pictures, correct?
You still need to verify the Gate drive diode/resistor network as suggested per post #35.

[litec systems]

Re: Diagnosing EAX64905001

So it tested shorted, correct and you replaced it when you replace the MOSFET and the resistor as shown in your pictures, correct?

The c102 was completely burnt, luckily I was able to read it's value
Yes, in additional to the th101 thermistor which had a hole on it( although it's still was changing resitance due to temperature changes 😂+ main fuse of course ( with a lower amp(3 instead of 5, probably because it's ready for 120 vac ) and fast blow type to minimize further damage on the future when the Mosfet will fail again

[litec systems]

Re: Diagnosing EAX64905001

You still need to verify the Gate drive diode/resistor network as suggested per post #35.

Can i test after desoldering only the Mosfet ic? ( i guess that it should " break " the "loop" on that circuit so it wont affect the meter if ill test each resistor?

And if I'll take the smd's resistors out and destroy them accidentally. Can i use 1\4w resistors instead ( with proper insulating) ? If not how much watt i need there?
( r108 is significantly bigger than r111, guessing that r108 acts as a kinda last little fuse? if so, it's still any hope & GOOD chance that the Mosfet IC is still alive? As i can't find it on digikey n mouser and on eBay there are feedback about fake chips
Sorry for asking again, but isn't a chance that an older SOP-8 Mosfet IC will be compatible?
If I'll give it a try, it may further damage the PSU or it'll just won't work?
Sorry for my dumb questions, I'm not such understand on electronics

[budm]

Re: Diagnosing EAX64905001

1) There is no chance that IC survive when R106 (220 Ohms) connected to the CS pin of the IC is blown, large amount of current has flown through that resistor to ground.
2) Please look at the schematic again and see how the Gate diode/resistor network is connected together, as you you can see if you understand series parallel circuit you will then see why when you test D103 it shows conduction in both directions. If you do not understand then you need to go online and study series and parallel circuit.
3) At this point what is the resistance reading of R108 (100 Ohms), and R107 (22 Ohms)?
4) You need to get the same SMPS IC with the same P/N. Just search the P/N and see what you get. See spec sheet of SSC1S31XA attached. Notes:Verify that is the IC being used in your board version.
5) "And if I'll take the smd's resistors out and destroy them accidentally. Can i use 1\4w resistors instead ( with proper insulating) ? If not how much watt i need there?" You can use 1/4W in place of those small SMD resistors but you have to do clean soldering works to make sure no solder bridged occur.
6) You need to read post #27, #28 since it looks like you have bad resistors on some of the SMPS IC pins look at the PDF schematic on post #31.
7) At this point you have lots of damaged parts on this board.

[litec systems]

Re: Diagnosing EAX64905001

Hi
So I've desoldered that ic,
Here are its markings
SSC1S311
Sk2d3a\ Sk203a ( not sure if it's a "D\A"
518t

And here are the values of the 2 resistors + D103 ( while only the IC isn't in the circuit)

R108(101 markings on it) = 100.1 ohms

R107(220 markings on it) =22.6 ohms

R111 ( 103 markings on it) =10.00 k ohm

So far, looks good right? �� ( besides the Mosfet ic that I don't know where to find a cheap replacement that will actually work and wont be fake)

D103,while still on circuit ( but without the Mosfet ic) = 0.150 in both directions, but as you said its because it's connected together ( if you suggest to test it outside the circuit to fully troubleshoot the psu, Could you please advise me which temperature to set my ( fake hakko 936) 75w soldering iron, to minimize the risk of blowing that tiny diode? Or i can set it to the highest level (450c) And do it quickly?
AND now, is there a reason to retest the Mosfet ic again while it's out of the circuit or if the R107 ( = it's " fuse" reads good) + as you said that there's no way that It'll survive after the current that passed through it?
Thanks for all! ����

[budm]

Re: Diagnosing EAX64905001

Hi
So I've desoldered that ic,
Here are its markings
SSC1S311
Sk2d3a\ Sk203a ( not sure if it's a "D\A"
518t

And here are the values of the 2 resistors + D103 ( while only the IC isn't in the circuit)

R108(101 markings on it) = 100.1 ohms

R107(220 markings on it) =22.6 ohms

R111 ( 103 markings on it) =10.00 k ohm

So far, looks good right? �� ( besides the Mosfet ic that I don't know where to find a cheap replacement that will actually work and wont be fake)

D103,while still on circuit ( but without the Mosfet ic) = 0.150 in both directions, but as you said its because it's connected together ( if you suggest to test it outside the circuit to fully troubleshoot the psu, Could you please advise me which temperature to set my ( fake hakko 936) 75w soldering iron, to minimize the risk of blowing that tiny diode? Or i can set it to the highest level (450c) And do it quickly?
AND now, is there a reason to retest the Mosfet ic again while it's out of the circuit or if the R107 ( = it's " fuse" reads good) + as you said that there's no way that It'll survive after the current that passed through it?
Thanks for all! ����

1) Those resistors are fine, but you still to test other resistors connected to the IC, you need to measure those other resistors connected to the IC, see the schematic.

2) Again, YOU MUST: "6) You need to read post #27, #28 since it looks like you have bad resistors on some of the SMPS IC pins look at the PDF schematic on post #31."

3) My post #17 "1) There is no chance that IC survive when R106 (220 Ohms) connected to the CS pin of the IC is blown, large amount of current has flown through that resistor to ground."
So I do not know why you are talking about R107, R107 is part of the Gate drive circuit, R106 (220 Ohms) is part of the current sensing circuit which you reported the resistance reading in your post #27:
"1. Smd, r106; 0.838 K OHM (it has a writing of 221\ [ or 122? ] but looks more like 221" this resistor is bad!

4) Your reply: "AND now, is there a reason to retest the Mosfet ic again while it's out of the circuit or if the R107 ( = it's " fuse" reads good) " it is not a fuse, it is a 22 Ohms resistor. There is NO reason to retest the SMPS IC! it is bad when that R106 is blown up, the high current went through R106 and the IC to circuit ground, REPLACE THE IC. It sounds like you do not want to replace the IC, no way you can use Ohm meter to test ALL the functions of the IC. You can replace all the parts without replacing the IC then you can power up the board to see if the new parts will blow up again or not, so be prepare to buy extra parts.

[litec systems]

Re: Diagnosing EAX64905001

. It sounds like you do not want to replace the IC, no way you can use Ohm meter to test ALL the functions of the IC. You can replace all the parts without replacing the IC then you can power up the board to see if the new parts will blow up again or not, so be prepare to buy extra parts.

Hi
I do want to replace that IC, but not at a cost of a half new 32 TV here, on the other hand, i like this tv
So I'LL do buy spares, I've thught of excacly the chance that they'll blow up again, but i cant find a reliable seller. I've found a "good + reasonable " price on eBay for 10 ic+ 10 Mosfets( just in case that somehow it'll blow again soon)
But reviews on all seller says that they're fake, which actually, if it'll work reliable, even just for 2 years each IC it's good enough, but im afraid that itll damage the PSU further and that's why i don't know what to do this ic is out of stock...
And there's a 2nd PSU'S on eBay for about 30 bucks BUT actually i want to learn how to diy repair it, but on the other hand, not spending more than a working psu( although i cant know how much life left on the ebay's PSU...
Below is the Sanken reply to my question on where i can get it...
Lg wont respond to me( and probably never will,as they want us to buy thier new TVS every 3 years

[budm]

Re: Diagnosing EAX64905001

Spending money is part of the learning, some time it will cost a lot, so how much learning is it worth to you? $10? $100? $1000? I spent A LOT of money and times myself, and it is a non-stop learning, I have been doing this for more than 40 years.

[litec systems]

Re: Diagnosing EAX64905001

Spending money is part of the learning, some time it will cost a lot, so how much learning is it worth to you? $10? $100? $1000? I spent A LOT of money and times myself, and it is a non-stop learning, I have been doing this for more than 40 years.

I know and you right, it's worth me alot that's why I've so badly want to repair it, and even invest more than a working psu on eBay, just on replacement components, but it's not that about the money, I will happily extend my budget on it, but the main thing is IT'S OUT OF STOCK AND IDK WHERE TO FIND it, even not original IC, just a safe working one( or more correctly, about 10 pcs lot SO I'll have spares.....)
It's not available on digikey etc...
And I've trashpicked almost every electronic related things since I was about 5 years old JUST TO LEARNING till this day that how i made a PC TECHNICIAN by about 8 years old...�� and im always want to learn more, by PRACTICING and thats why im here on 6.15AM ( Israel time) because Paralellicly I'm working on repairing ( at least trying to.. �� an logitech x210 speakers with amplifier issue [ which many people will think that it's not the effort, but as the issue is bigger, for me, its just more challenging me!! �� as again, I'VE NEVER TOOKED A COURSE, i like to self& hard learning by understanding what Im doing ��
Anyway, do you have an idea where i can get that ic?����

[budm]

Re: Diagnosing EAX64905001

You may have to take a chance and get it from EBAY or ALIEXPRESS.

[litec systems]

Re: Diagnosing EAX64905001

You may have to take a chance and get it from EBAY or ALIEXPRESS.

Hi
There are few listings on eBay for 10-12 usd per 10pcs of the MOSFET ic. I'll probably try my luck with them... ( as long as it's not sounds to you like 100% fake)
They have full 8 pins on the pictures mine's 7 pin is not present at all( theres no copper\ metal there at all
And there are few listings of the MOSFET MDF11N65B for about 15usd per 10pcs includes shipping..
On the Mosfet pictures the magnachip logo doesn't present \ visible... So i think its untrusted seller? Or should I give him a chance? ( most of the listing are like that)
Im not really care if it's original, i do care about very short MTBF \ reliability issues