Samsung 23" LCD P2350 Inverter Repair

[whistlergonewild]

Re: Samsung 23" LCD P2350 Inverter Repair

Yep. Bought them off eBay from a seller named mastation. They are pictured as nichicon which I believe is a good cap... Unless of coarse they are fakes.

[momaka]

Re: Samsung 23" LCD P2350 Inverter Repair

I have 5 x 1000uf 25V 105*C on the way from hong kong, just a matter of time before they get here.

Not to disappoint you, but caps from Hong Kong are usually cheap fakes, most of the time no better than Fuhjyyu, if not worse. Where did you buy them from, eBay? And if so, from which seller? There's only one I know of that sells genuine good quality caps.
When you get the caps, post some pictures here. Nothing worse than trying to repair something with cheap parts that don't work properly in the first place.

[PlainBill]

Re: Samsung 23" LCD P2350 Inverter Repair

Are you sure? Five legs?

Well, this is a case of the OP was wrong, but I didn't correctly identify the part either; I was going by the location, not the number of legs. It's not a voltage regulator, it's not a power FET. Rtech is almost certainly correct, it's a SMPS controller and power FET rolled into one.

Which explains why the power supply is shutting down from overheating. Now all someone has to do is come up with an explanation of WHY it is overheating.

PlainBill

[Rtech]

Re: Samsung 23" LCD P2350 Inverter Repair

May be a combined FET and PWM component, regularly used in a lot of monitors,

[pedro]

Re: Samsung 23" LCD P2350 Inverter Repair

That's not a voltage regulator; it's a power FET.

Are you sure? Five legs?

[whistlergonewild]

Re: Samsung 23" LCD P2350 Inverter Repair

Awesome. I can't wait to get my new good quality caps in the mail.

[retiredcaps]

Re: Samsung 23" LCD P2350 Inverter Repair

Replacing crappy caps with used crappy caps is sorta like replacing the flat tire on your car with a spare tire that's also flat.

Too funny. I was going to use a tire analogy almost identical to yours in my original post, but decided not to. I guess I should have.

[jetadm123]

Re: Samsung 23" LCD P2350 Inverter Repair

I do agree with retiredcaps. Replacing crappy caps with used crappy caps is sorta like replacing the flat tire on your car with a spare tire that's also flat. Really difficult to establish a good starting point, since we don't know if your replacement caps are any good or not.

[retiredcaps]

Re: Samsung 23" LCD P2350 Inverter Repair

I ended up finding an old computer power supply ...

but I imagine it may be because all the other caps I ripped outta the power supply do say Fuhjyyu on there sleeves.

Fuhjyyu has the one of worst reputations here. Your problem could very well be that you are using used crappy caps. That is, the original caps are bad and now you are using bad caps again and not eliminating caps as a potential problem.

The cost of *new* quality low ESR caps are cheap when repairing this 23 inch monitor.

Capacitors die from age, heat, and shoddy build quality. Capacitors DO NOT have to be visibly bloated in order to bad. They can be out of tolerance uF (a 1000uF measures 20uF) and/or have high ESR (ohm). A multimeter will be insufficient to test for ESR. For that you need an ESR tester which costs between $50 and $300.

Most members here will recommend that you replace ALL capacitors with reputable brands from reputable sellers. Brands like Rubycon, Panasonic, and United Chemicon are suggested. A list of recommended caps can be found at

https://www.badcaps.net/forum/showthread.php?t=2280

[whistlergonewild]

Re: Samsung 23" LCD P2350 Inverter Repair

I ended up finding an old computer power supply, which had several caps in it. I took the 47uf 50V from that. It was really an old power supply so very dusty and you can see the cap is a bit dirty. I know the voltage is a bit high but I thought I would put it in and see what kinda results I got. It is not written Fuhjyyu on the sleeve, but I imagine it may be because all the other caps I ripped outta the power supply do say Fuhjyyu on there sleeves.

I have replaced all the caps now except for the 2 x 1000uf 25V and the really big one. The 3 x 1000uf 10V I replaced with 3 x 1000uf 16v but only 85*C instead of the 105*C that were originally in there. I have 5 x 1000uf 25V 105*C on the way from hong kong, just a matter of time before they get here.

I changed the 12volt CPU fan to operate off the 5.1Volt because it was too loud operating @ 16V. However, now it continues to shut off and on.

[retiredcaps]

Re: Samsung 23" LCD P2350 Inverter Repair

Replaced all five of the 1000uf and the two 47uf....still the same problem.

In your power FET close up picture, it shows TNR 47uF 50V.

1) Is that the replacement cap or original cap?

2) If it is the replacement cap, is a new cap or a reused cap?

3) Does the TNR have Fuhjyyu on the sleeve?

[whistlergonewild]

Re: Samsung 23" LCD P2350 Inverter Repair

This is what it looks like rigged up with a fan.

[PlainBill]

Re: Samsung 23" LCD P2350 Inverter Repair

I believe what I am talking about is the heatsink and voltage regulator.

You can see what I a calling the regulator attached to the heatsink. I believe it is inscripted with:
f DK16
S
65R

That's not a voltage regulator; it's a power FET.

PlainBill

[whistlergonewild]

Re: Samsung 23" LCD P2350 Inverter Repair

I believe what I am talking about is the heatsink and voltage regulator.

You can see what I a calling the regulator attached to the heatsink. I believe it is inscripted with:
f DK16
S
65R

[retiredcaps]

Re: Samsung 23" LCD P2350 Inverter Repair

Could it possibly be the voltage regulator itself?

On most lcd monitors, there are no voltage regulators on the power/inverter board. The voltage regulators are normally used on the logic board to convert 5V DC down to 3.3V, 2.5V and/or 1.8V DC.

In post #15, you talk about a small fan cooling off the heatsink. What heatsink are you referring to?

[whistlergonewild]

Re: Samsung 23" LCD P2350 Inverter Repair

Replaced all five of the 1000uf and the two 47uf....still the same problem. Could it possibly be the voltage regulator itself? If so how do i find this part number or what the rating is and where do i buy it?

[whistlergonewild]

Re: Samsung 23" LCD P2350 Inverter Repair

Thanks DGtech,
Thanks for the quick reply. I had only replaced one cap but with no real results. The only reason is that I live in the mountains, and we don't really have anywhere to buy caps. I just noticed that I can buy them off this website so I may go along that route. I only need eight of them.

2x25v 1000uf
3x10v 1000uf
2x25v 47uf
1x16v 100uf

[Dgtech]

Re: Samsung 23" LCD P2350 Inverter Repair

Did you ever replace the capacitors? If not, this may be the reason the thing is heating up so much. If the regulator is heating up then it's having to release excess energy in the form of heat. You can put a fan on it and keep putting band - aid's on the original problem however, it will pop up again.

[whistlergonewild]

Re: Samsung 23" LCD P2350 Inverter Repair

Ok. So I hooked up a little 12V CPU fan to cool off the heat sink. It WORKED, the fan has cooled the heat sink and it doesn't turn off the monitor.

The only problem is the fan is really loud. Im thinking of putting some new silicone glue or thermal compound stuff behind the voltage regulator to see if this will help.

?Besides new glue, or thermal compound is there something else besides the fan that will disipate the heat better so my monitor will stop shutting down?

[pamr4]

Re: Samsung 23" LCD P2350 Inverter Repair

Check the inverter transformer secondaries. I must have around 1.21Koms each.