Samsung HP-S4253 Power supply repair

[cedward138]

Re: Samsung HP-S4253 Power supply repair

Strangely, The cap seems fine after removing the disk.

[selldoor]

Re: Samsung HP-S4253 Power supply repair

Blast! that is going to raise more comment
If you have cleaned up the board put it back in with the disc back in if its whole then perhaps we can start again.
Working just with that board at the moment plug it in and CAREFULLY test
the voltage on that cap - meter on vDC600

[cedward138]

Re: Samsung HP-S4253 Power supply repair

I now suspect it was chocolate ice-cream spilled by someone just prior to getting my DMM out and making the connection to the mains.

Let me put the cap back in and will measure and report the voltage soonest

[selldoor]

Re: Samsung HP-S4253 Power supply repair

Well another sticky eh? or a new ICe inserted
With any luck the board was faulty enough at the outset to not start up.
If it did may have taken out a few parts- we shall see.

[cedward138]

Re: Samsung HP-S4253 Power supply repair

The cap is in series with the 3 adjacent ones. Voltage measurement 168 v

[selldoor]

Re: Samsung HP-S4253 Power supply repair

Well that is a good start - any 5v on the socket that goes to the main board
5stby

[cedward138]

Re: Samsung HP-S4253 Power supply repair

No stnby 5 v

[selldoor]

Re: Samsung HP-S4253 Power supply repair

Your small parts of the board pictures are driving me mad - can you try again for a full board picture. What is the board number I will try and find one on line to look at.
You say you tested the fuses -did that include the red barrel fuses? Can you test again in view of ice - say how many ohms

[cedward138]

Re: Samsung HP-S4253 Power supply repair

Sorry, only cell phone available for pics at this time.
Board no. is BN96-03252A
Hope you can find one online.
Fuses still testing ok Have to set meter to 200M to get reading other than 0.00, then reads 1.1

[vinceroger69]

Re: Samsung HP-S4253 Power supply repair

http://www.shopjimmy.com/media/catal...bn9603252a.jpg


there are three barrel type fuses on the primary side just under the four black capacitors marked f102 etc can you test these for us as per selldoors post 28 too there are also 2 5w white resistors oblong shaped with red writing on do these test ok too

[cedward138]

Re: Samsung HP-S4253 Power supply repair

yes they do. See post 29

[vinceroger69]

Re: Samsung HP-S4253 Power supply repair

the white resistors too? i can see five fuses in total 2 white 3 barrel have you found any more?

[cedward138]

Re: Samsung HP-S4253 Power supply repair

5 total just as you.
F101, white, near AC input jack
F401, white, just above 4 big caps
F102, brown barrel, below 4 big caps
F501, brown barrel, next to F102 and heat sink
F601, brown barrel, a little further down about halfway along heatsink

[vinceroger69]

Re: Samsung HP-S4253 Power supply repair

cool thats a start then see if you can test those white resistors next i see two

[cedward138]

Re: Samsung HP-S4253 Power supply repair

want to be certain of correct resistors. Do you have the number or give approximate location please

[cedward138]

Re: Samsung HP-S4253 Power supply repair

If we're referring to R453 and R510, then those test ok

[vinceroger69]

Re: Samsung HP-S4253 Power supply repair

there is a repair kit to fix the psu there on ebay pity i doesnt say the locations of the mosfet transistors so we can test them the resistors there is one top right of the board
the other r510 i think
copy pasted from ebay page!
Kit content:
2 MOSFET Transistors
11 Electrolytic capacitors

Fixes following symptoms:
-shuts down
-goes on/off by itself
-won't come on
-dead

[cedward138]

Re: Samsung HP-S4253 Power supply repair

Ok, so we are talking the same components. Both test ok
If you can locate the mosfets and direct me, I will test them and report

[selldoor]

Re: Samsung HP-S4253 Power supply repair

That is a problem - I too saw the kit while looking for a picture and as vince says there are no clues. You will need to try and get the part numbers of the components fixed to the heatsinks.
Start with the pair to the left of the transformers

[vinceroger69]

Re: Samsung HP-S4253 Power supply repair

That is a problem - I too saw the kit while looking for a picture and as vince says there are no clues. You will need to try and get the part numbers of the components fixed to the heatsinks.
Start with the pair to the left of the transformers

also i sure tom mentioned these psus are prone to dry joints on the solder i would reheat and melt some fresh solder into all the leg joints to each item fixed to the heat sinks ie transistors/fets they may look ok but well worth doing imo.