mercury pc power supply only 5vsb supply.

[R_J]

Re: mercury pc power supply only 5vsb supply.

How many "beeps" give you a reading of .6xx in diode test?

[playit]

Re: mercury pc power supply only 5vsb supply.

hi RJ this is how it looks now.. i tried my best to put the resistor on R23 and to the jumper ,as no pads are there,they got lifted and teared.. i am sorry i am asking too much.. please do reply when you have time,thanks

[playit]

Re: mercury pc power supply only 5vsb supply.

oh you replied i dint see it, transmitter game me one continuous beep ,also there is another problem now..the circuit slided and fell 2 times ,then no power came to board,no 5vsb,then i tried to switch on from back,the switch clip was broken loose,now i will get it ,and try again for the voltages.. is there anything else i should try checking again before i list components to be bought ?
also i found one of the 4148 zener diode(in pairs) was dead-no reading ,it was at place of R23. i replaced with ph4148

[R_J]

Re: mercury pc power supply only 5vsb supply.

A 1n4148 is not a zener diode, When checking a transistor or diode with diode test, a silicone junction usually reads about .6xx in diode test. (this number is the voltage drop across the junction) meters with continuity "BEEP" will beep betwen 0 and 150Ω.

[playit]

Re: mercury pc power supply only 5vsb supply.

in the mean time..i will test the diodes ,transistors again,i have an doubt are R23- R32- jumper are connected someway in the middle,i see a little copper head there,
also i want to ask you about this pair 4148 zeners, the pair which is d25,d29. i get reading when i touch negative of d25 and positive of d29 ,as if they working in pairs, but i dont get the same reading for zeners pair near R23 like working in double,but ok when i measure single

[playit]

Re: mercury pc power supply only 5vsb supply.

A 1n4148 is not a zener diode, When checking a transistor or diode with diode test, a silicone junction usually reads about .6xx in diode test. (this number is the voltage drop across the junction) meters with continuity "BEEP" will beep betwen 0 and 150Ω.

oh ok ,thanks.. this psu got my nerves..i just dont want give it up until something very bad has happened to it ..like it just cant be fixed at all! its just we nearly repaired it well but then i spoiled it.. its so not acceptable

[R_J]

Re: mercury pc power supply only 5vsb supply.

The diodes D25-D29 are in a different circuit than the diodes near R23.

[playit]

Re: mercury pc power supply only 5vsb supply.

The diodes D25-D29 are in a different circuit than the diodes near R23.

yes they give readings when read together, but the d9-d10 doesnt give reading like that.. did i fix it wrong... d9 was the one dint give any reading,i removed it and replaced it with ph4148

also could you please compare the old and new R23 areas.. i doubt the jumper/R23/d9 was together soldered ???

[playit]

Re: mercury pc power supply only 5vsb supply.

this time i checked carefully ..the transistor-- the horizontal - black at base- 676- 699
reversed gave- red at base -1749 - 1852
the vertical at base- continuous beep - black at base- continuous beep-value decreases- o-1812
reversed gave - red at base- continuous beep value 0 - 362

[playit]

Re: mercury pc power supply only 5vsb supply.

back with 5vsb ,it was broke positive white wiring,fixed it and back with 5vsb .

[playit]

Re: mercury pc power supply only 5vsb supply.

d10 positive has continuity with the copper foil near the junction..i tested the continuity,so according to old pic in which i dint rip off .. are these junction/d10 4148 positive/resistor all soldered together?

[playit]

Re: mercury pc power supply only 5vsb supply.

should d9 and d10 to be soldered or shorted in someway..
what could be the reason for not getting 16 v or any voltage at other side of the resistor.. any idea how the circuit joins with 2 x 4148 and a resistor.. ? i tried to google it..not much help there..

[R_J]

Re: mercury pc power supply only 5vsb supply.

This is how the trace should be. and this is how to connect that 1.5k resistor. You need to connect the RED diode anode to the grey jumper wire (yellow trace)
One end of the resistor can connect to the jumper wire and the otherend to the blue diode cathode.

Your R23 should be the same as R24 on the schematic

[playit]

Re: mercury pc power supply only 5vsb supply.

thank you for replying.. i will do it.. after doing it what voltage should i expect on the other side of resistor ? and i am confused whether i really saw 2 4148 diodes ? is that correct there would be 2 4148 there or i am mistaken for some other diodes ?

[playit]

Re: mercury pc power supply only 5vsb supply.

transistors readings in post #49 are ok?

[R_J]

Re: mercury pc power supply only 5vsb supply.

There are lots of 1N4148 diodes in this power supply, Plese look at the schematic and you will see they are used everywhere. The two diodes (D9,D10) are likely the same as D10 and D15 on the schematic.
On one side of R23 you should have 16v on the other side it could be around 10~12 volts?

[playit]

Re: mercury pc power supply only 5vsb supply.

hmm ok nods ..i dont have schematics ..i mean like a circuit diagram but yes.. i saw they are all over the board.. just wanted to be sure if i am messing up amymore.. today i will fix the tracings and see what i get

[R_J]

Re: mercury pc power supply only 5vsb supply.

hmm ok nods ..i dont have schematics ..i mean like a circuit diagram but yes.. i saw they are all over the board.. just wanted to be sure if i am messing up amymore.. today i will fix the tracings and see what i get

Look at Post #8.... It is not the EXACT schematic but is very close.

[playit]

Re: mercury pc power supply only 5vsb supply.

oh ya cool.. now i see the point

[playit]

Re: mercury pc power supply only 5vsb supply.

if it helps.. i found the model number but couldnt get it from internet.. mercury model ckp-3400 gc14244 -- this was written on the box of this power supply lid