step down adjustable convertor 60vdc Help on ID of part

[mttrout]

Hello, I am in need of information of a item on ..This link..

http://www.ebay.com/itm/181005179070?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 @ top where voltage In wiring comes there is a capacitor marked 63v 1000uf
to left is the burnt item it had 3 prongs that is mounted between print board & heat sink # on board T3 and heat sink prongs come to top of board. then  capacitor in middle then another 3 prong # stamped on board D6 it also is sandwiched between back of board and heat sink.
Any help in Id so parts may be ordered for repair.

Much appreciated for any ideas.
Chuck

[OperaHouse]

Those pictures tell me nothing since they don;t show the parts.  I imagine any power fet from the low voltage section of a UPS would work.  Like to know what you were doing that caused this, input and output voltages and current.  If operating near 60V that would be chancy as most common power FET are 50-60V.  The specs of these modules are dubious but they generally protect themselves pretty well.

[mttrout]

Thanks, I had set unit up on bench then disconnected unit.thinking it would hold my settings.
when it was re hooked it did not see my prior settings... 48 volt system to 12 v. so in doing it while active the magic smoke appeared. to high of amp output.since have installed a fuse on this line when I get it repaired. The picture I tried uploading would of helped I know..Sorry.
went to web site copied the pic. but it does not show the Id part under board.
The top large capacitor is where the prongs come up into board.
Chuck

[OperaHouse]

Without seeing the device no one can tell if second three terminal device is a FET or dual diode.  A second issue is whether the shorted device took out the driver electronics. You are operating on the hairy edge with a 48V system where voltages can easily climb over 60V with no load.  This board was not a good chioce for your system without modifications.  Chances there are other problems that actually preceeded output destruction.

[mttrout]

Thanks Operahouse. While typing this I read your reply's thanks

I removed burnt part  this morning and using bright lite and Magnifier the first
#'s   are   P75NF75@ lower letters - - - not clear then 10F      6
after your tip on mosfet went to flea bay P75NF75    also transistor showed under this search
what difference between? the other unknown Item  on right of capacitor # LT    74S or a 6 on top bottom left corner symbol -->+black dot+<--

 the mosfet unit ? has small notches on each side the other unknown on right is squared.

Thanks for your help

[OperaHouse]

Check and see if the two outside pinsof the unknown device  are connected together on the circuit board.  If they are, that device is a diode..  Dioses in switching applications have to be fast recovery.  common diodes will not work.   Chances are it is just a diode.  If this was sync rectification, both diodes would likely be the same number.

[Mary B]

lt74s is an integrated circuit in the 74 series, need more numbers

[mttrout]

Thanks..OperaHouse
Yes.. The two outer pins are hooked to the - side of the Capacitor's solder line.this would go with the symbols on lower part ...  the other center pin connects downstream of the other unknown device on the + side of Capacitor.
Thanks half way there..
the other looking on back ties into the + line voltage down stream of Capacitor with its center pin attached onto solder line.and  1 leg goes to the dbl. diode line center pin this solder line stops to enter the Large wound copper coil.. after going through coil ends at vo  line wire attachment..where it goes into bottom board.. 2 outer  pin of the unknown mosfet or transistor goes to board but appears for support only.

Chuck

[mttrout]

Thanks MaryAlana,
           # below MDR2012 10       the # on this board 2012.10
hope this helps. the printed circuit board does have # on front side the unit that
is soldered into the voltage + solder down stream board #T3 the print on it's surface
P75NF75.. .....the dbl. diode mounted on the negative side D6   has printed on board..

Chuck

[OperaHouse]

Could it be MBR instead of MDR?  Something like this would work Schottky Barrier Diode-MBR10200FCT found on ebay.  Anything over 100V and 10A would work.

[Mary B]

the LT74 part number would be on the chip, it is an integrated circuit of some sort.

[mttrout]

Thanks to you both, OperaHouse  MaryAlana
The MDR was a MBR under better lighting. so it ID'd the shootky barrier Double diode.

MaryAlana

Now the burnt unit with the P75NF75 under this new light at bottom there seems to
P75NF75 @
RCC 1DE  6       front could be a R but clearness not sure
MA _  51C       
The burnt unit has a notch's on each side about 1/4 way up from pins and 1/4" hole @ top of heat sink for screw.
Thanks two you both for the help..
You both have a great evening.
Chuck

[OperaHouse]

Now that you have identified those parts I would look for regulators that power the electronics on the board.  These can be powered up without those other parts installed.  If you are only operating at higher voltages, I would be cutting a trace and adding a resistor to drop the voltage to the board regulator if the top operating voltage is 60V