need replacement transistor

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • xelectech
    retired tech
    • Nov 2014
    • 238
    • USA

    #1

    need replacement transistor

    Hi,

    hoping someone can ID or suggest a replacement for one found in an antec EA-500 psu:


    6 4 7
    6 L 4

    e c b

    It's a TO-92 case, the second line of #'s are spaced more widely. It's in the 5vsb ckt., I busted a lead off trying to remove some of the tan glue from it's legs.
  • SteveNielsen
    Retired Tech
    • Jun 2012
    • 2327
    • USA

    #2
    Re: need replacement transistor

    Google

    It's probably a 2sb647

    e c b is the pinout; emitter, collector, base
    Last edited by SteveNielsen; 02-08-2016, 10:24 AM.

    Comment

    • budm
      Badcaps Legend
      • Feb 2010
      • 40746
      • USA

      #3
      Re: need replacement transistor

      How is the Transistor connected to other components? Good clear pictures of both sides of the board?
      Never stop learning
      Basic LCD TV and Monitor troubleshooting guides.
      http://www.badcaps.net/forum/showthr...956#post305956

      Voltage Regulator (LDO) testing:
      http://www.badcaps.net/forum/showthr...999#post300999

      Inverter testing using old CFL:
      http://www.badcaps.net/forum/showthr...er+testing+cfl

      Tear down pictures : Hit the ">" Show Albums and stories" on the left side
      http://s807.photobucket.com/user/budm/library/

      TV Factory reset codes listing:
      http://www.badcaps.net/forum/showthread.php?t=24809

      Comment

      • xelectech
        retired tech
        • Nov 2014
        • 238
        • USA

        #4
        Re: need replacement transistor

        Originally posted by SteveNielsen
        Google

        >I did, tried bing, yahoo, digikey and mouser also, as well as alldatasheet

        It's probably a 2sb647

        >that may be it - at least they are both pnp's

        e c b is the pinout; emitter, collector, base
        Thanks Steve

        Comment

        • xelectech
          retired tech
          • Nov 2014
          • 238
          • USA

          #5
          Re: need replacement transistor

          Originally posted by budm
          How is the Transistor connected to other components? Good clear pictures of both sides of the board?
          My good camera is down right now, it may be able to take a better pic of the bottom - the emitter was connect to R601 on the bottom of bd., (a surface mount one), the collector was connected to R602, (15 ohms) near the heatsink, right in the area where the purple wire is.

          I removed a 220uf 16v cap, which reads ok in esr and capacity. The transistor tests ok too, both diode junctions only read one way, about 640mV.

          Thanks Bud
          Attached Files

          Comment

          • SteveNielsen
            Retired Tech
            • Jun 2012
            • 2327
            • USA

            #6
            Re: need replacement transistor

            Their solder-wave must have been running cold, that blobby shit would have never made it past me when I did QA.

            Comment

            • xelectech
              retired tech
              • Nov 2014
              • 238
              • USA

              #7
              Re: need replacement transistor

              Originally posted by SteveNielsen
              Their solder-wave must have been running cold, that blobby shit would have never made it past me when I did QA.
              It is pretty ugly, rather hard to make out which component's leg is sticking through where -
              I don't think it's been worked on before, I put all the scratches on it trying to get rid of some whitish powdery stuff that was between the traces in several places.

              Comment

              • japlytic
                Badcaps Legend
                • Oct 2005
                • 2086
                • Australia

                #8
                Re: need replacement transistor

                With Japanese transistor types, "2S" is usually omitted on the device markings, and I have seen some which also omit A/B/C/D markings.
                My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.

                Comment

                • xelectech
                  retired tech
                  • Nov 2014
                  • 238
                  • USA

                  #9
                  Re: need replacement transistor

                  Originally posted by japlytic
                  With Japanese transistor types, "2S" is usually omitted on the device markings, and I have seen some which also omit A/B/C/D markings.
                  Thanks for the info. I guess a comprehensive cross-reference book is a thing of the past now.

                  Comment

                  • stj
                    Great Sage 齊天大聖
                    • Dec 2009
                    • 31002
                    • Albion

                    #10
                    Re: need replacement transistor

                    put the old one on a tester to see if it's npn or pnp etc.

                    Comment

                    • xelectech
                      retired tech
                      • Nov 2014
                      • 238
                      • USA

                      #11
                      Re: need replacement transistor

                      Originally posted by SteveNielsen
                      Their solder-wave must have been running cold, that blobby shit would have never made it past me when I did QA.
                      Hey Steve, just wondering can you tell me if the surface-mounted components are put on the board before, or after, it goes through the wave-soldering operation?
                      Last edited by xelectech; 02-09-2016, 09:56 AM.

                      Comment

                      • vinceroger69
                        Badcaps Legend
                        • Mar 2012
                        • 6714
                        • uk

                        #12
                        Re: need replacement transistor

                        A good video showing wave soldering
                        https://www.youtube.com/watch?v=Ap-HY7qP9zE

                        Comment

                        • budm
                          Badcaps Legend
                          • Feb 2010
                          • 40746
                          • USA

                          #13
                          Re: need replacement transistor

                          At :34~36 you can see she twisted the black heatsinks for the SMD ICs, so the SMD components were already went through the SMD process before the wave soldering process.
                          Never stop learning
                          Basic LCD TV and Monitor troubleshooting guides.
                          http://www.badcaps.net/forum/showthr...956#post305956

                          Voltage Regulator (LDO) testing:
                          http://www.badcaps.net/forum/showthr...999#post300999

                          Inverter testing using old CFL:
                          http://www.badcaps.net/forum/showthr...er+testing+cfl

                          Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                          http://s807.photobucket.com/user/budm/library/

                          TV Factory reset codes listing:
                          http://www.badcaps.net/forum/showthread.php?t=24809

                          Comment

                          • xelectech
                            retired tech
                            • Nov 2014
                            • 238
                            • USA

                            #14
                            Re: need replacement transistor

                            Originally posted by vinceroger69
                            A good video showing wave soldering
                            https://www.youtube.com/watch?v=Ap-HY7qP9zE
                            Thanks, I'll check that out next time I get to the library.

                            I have seen 2 different setups in operation, one at Spacelabs (a biomedical equipment mfgr.) in the early '80s, and another in the mid-80s at a dental xray equip. mfgr. - don't know when surface-mounted stuff came on the scene, but there wasn't any back then that I'm aware of.

                            Comment

                            • xelectech
                              retired tech
                              • Nov 2014
                              • 238
                              • USA

                              #15
                              Re: need replacement transistor

                              Originally posted by stj
                              put the old one on a tester to see if it's npn or pnp etc.
                              Kinda hard to do that, one of the legs is busted off flush - still possible to test the diode-junctions, though, it's a pnp.

                              Comment

                              • SteveNielsen
                                Retired Tech
                                • Jun 2012
                                • 2327
                                • USA

                                #16
                                Re: need replacement transistor

                                Where I worked they were just starting to test running boards with smt parts thru the solder wave and trying out different glues. This was quite some time ago and smt parts were not widely used yet.

                                Comment

                                • stj
                                  Great Sage 齊天大聖
                                  • Dec 2009
                                  • 31002
                                  • Albion

                                  #17
                                  Re: need replacement transistor

                                  you do wave-solder smd
                                  to do it you need 2 things.

                                  1: you need to glue the parts down - annoys the hell out of me when i need to replace them!
                                  2: on chips you need larger pads on the end the wave flows towards to catch the solder before it bridges anything.
                                  you often see an arrow on these boards indicating the direction of the wave.

                                  Comment

                                  • xelectech
                                    retired tech
                                    • Nov 2014
                                    • 238
                                    • USA

                                    #18
                                    Re: need replacement transistor

                                    Originally posted by stj
                                    you do wave-solder smd
                                    to do it you need 2 things.

                                    1: you need to glue the parts down - annoys the hell out of me when i need to replace them!
                                    2: on chips you need larger pads on the end the wave flows towards to catch the solder before it bridges anything.
                                    you often see an arrow on these boards indicating the direction of the wave.
                                    Interesting! Thanks

                                    Comment

                                    • xelectech
                                      retired tech
                                      • Nov 2014
                                      • 238
                                      • USA

                                      #19
                                      Re: need replacement transistor

                                      Looking for a suitable replacement still - I found a similar tranny in a psu (guess I should have mentioned that the broken one is in either a to92-L or to92-MOD, but I didn't know at the time), here's a couple datasheets, the 2sb647 being the original and the ksa928a being similar (but is it similar enough?)

                                      Not sure anything attached, can't see it in the preview...

                                      Nope, couldn't load the links - anyway, does anyone know if these two transistors are close enough that I can use the ksa928a in place of the 2sb647?

                                      Thanks for any insight...
                                      Last edited by xelectech; 02-13-2016, 07:59 AM.

                                      Comment

                                      • tw2005
                                        Badcaps Legend
                                        • Oct 2011
                                        • 6458
                                        • Australia

                                        #20
                                        Re: need replacement transistor

                                        http://alltransistors.com/crsearch.p...e=60&caps=TO92


                                        Type Designator: 2SB647

                                        Material of transistor: Si

                                        Polarity: PNP

                                        Maximum collector power dissipation (Pc), W: 0.9

                                        Maximum collector-base voltage |Ucb|, V: 100

                                        Maximum collector-emitter voltage |Uce|, V: 80

                                        Maximum emitter-base voltage |Ueb|, V: 0

                                        Maximum collector current |Ic max|, A: 1

                                        Maksimalna temperatura (Tj), °C: 125

                                        Transition frequency (ft), MHz: 70

                                        Collector capacitance (Cc), pF:

                                        Forward current transfer ratio (hFE), min: 60

                                        ---------------------------------------------------------------------------------------

                                        Type Designator: KSA928A

                                        Material of transistor: Si

                                        Polarity: PNP

                                        Maximum collector power dissipation (Pc), W: 1

                                        Maximum collector-base voltage |Ucb|, V: 30

                                        Maximum collector-emitter voltage |Uce|, V: 30

                                        Maximum emitter-base voltage |Ueb|, V: 5

                                        Maximum collector current |Ic max|, A: 2

                                        Maksimalna temperatura (Tj), °C: 150

                                        Transition frequency (ft), MHz: 120

                                        Collector capacitance (Cc), pF: 48

                                        Forward current transfer ratio (hFE), min: 100

                                        Comment

                                        Related Topics

                                        Collapse

                                        • Haaheim
                                          Bias matching replacement transistor - Parasound 2250
                                          by Haaheim
                                          Hi guys!

                                          I am currently working on a Parasound 2250 (class AB), which had one defective channel. Components in the signal paths have been replaced, including an output transistor (2SC3519).



                                          According to the manufacturer, bias is adjusted by measuring 1-3mV across the output resistors. The original ones are completely fine around 1.5mV, but the replacement is not. Initially, I got a couple from eBay, assumed they were fake (they were) and was able to source a replacement locally. This exhibits similar behaviour, being around 0.6-0.8mV on its emitter resistor....
                                          05-13-2022, 12:45 PM
                                        • the_rem
                                          Unknown transformer : how to find a good replacement part ?
                                          by the_rem
                                          Hello guys,

                                          I would like a quite old but still good 800 W ATX PSU to be repaired. The problem was an extremely heavy coil whine coming from the small secondary transfomer on the PCB.

                                          I desoldered it hoping the references on the upper side would allow me to find a adequate replacement part. Sadly the written references drove me nowhere but to the manufacturer (I-MAG). I sent them a message like a bottle in the see asking them to send me a datasheet of the transformer. And... They responded ! I received a kind of datasheet (see attachment) but my competencies do not allow...
                                          04-23-2025, 01:48 AM
                                        • ezenia
                                          PS4 controller left stick potentiometer replacement issue
                                          by ezenia
                                          Hello,

                                          Not sure if this is the correct section, but I have a PS4 controller that I am trying to fix. It developed stick drift on the left stick and the usual simpler methods did not fix the problem.

                                          So I went on eBay and ordered some replacement potentiometers. https://www.ebay.co.uk/itm/174967976757 is where I got them from.

                                          I took the green potentiometers off the replacement sticks and soldered them onto the PCB. Assembled the controller and ran some tests. The drifting was somewhat fixed (not fully in center, but way better than before). However,...
                                          09-30-2023, 02:19 PM
                                        • boosti45
                                          Macbook pro logic board replacement parts quesion
                                          by boosti45
                                          i have a 2020 macbook pro 13" A2251 with 820-09149 logic board so i found an issue with chip labeled U6903 according to schem. boardview using flexBV software, so i removed it from the board and the issue im having is that the chip says "07A08FI ELC180​" on top of it but when searching for a replacement chip, i can find tons of identical looking chips that also have "ELC180" printed on them but the first set of digits is never the same so im trying to find out if i need this exact chip with these same numbers as mine and if not which ones are compatible as a replacement?...
                                          08-21-2024, 05:23 AM
                                        • RickyZA
                                          Help choosing replacement SMD transistor
                                          by RickyZA
                                          Hi there everyone,

                                          Im looking for a replacement transistor for my TV's logic board, unfortunately i had a newbie slip and shorted out the Pwr_On to the 20v rail with the mainboard connected, not very clever at all i know. Here is the damage.

                                          Transistor Close up

                                          Original Transistor Datasheet : RT1P141C Marked P1

                                          Main Board Schematic for transistor Reference: Service Manual / Main board Schematic Not the exact same model but im pretty sure they use the same transistors marked P1 which is the RT1P141C.

                                          My other question is...
                                          06-30-2017, 01:46 PM
                                        • Loading...
                                        • No more items.
                                        Working...