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Graco ST MAX II 495 PC PRO , paint spray machine help

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    Graco ST MAX II 495 PC PRO , paint spray machine help

    Hi all

    Customer mentioned that he overloaded this unit by powering with all settings at full .

    Anyone worked on this model before ?

    It's a US made device .

    A schematic would be really helpful , but not holding my breath .
    Attached Files

    #2
    Re: Graco ST MAX II 495 PC PRO , paint spray machine help

    Originally posted by zen View Post
    Hi all

    Customer mentioned that he overloaded this unit by powering with all settings at full .

    Anyone worked on this model before ?

    It's a US made device .

    A schematic would be really helpful , but not holding my breath .
    I found a repair manual but no pcb schematic. Is there a part number on the pcb
    Attached Files
    All donations to badcaps are welcome, click on this link to donate. Thanks to all supporters

    Comment


      #3
      Re: Graco ST MAX II 495 PC PRO , paint spray machine help

      Thanks

      16X297 seems to be the PCB number .

      Quite funny when i type it into Google . A repair kit popped up , which is the whole board , at a cost of £370

      Comment


        #4
        Re: Graco ST MAX II 495 PC PRO , paint spray machine help

        So far found C14,C15,C16 & C17 ( 47MF , 25V ) , poor ESR readings .

        Also D16 , which seems to be O/C , has previously been reworked and/or replaced .

        Messaged customer to find out what the hell is going on .
        Attached Files

        Comment


          #5
          Re: Graco ST MAX II 495 PC PRO , paint spray machine help

          C20 looking preggo, D16 pin not soldered, was a gorilla inside trying to fix this?

          Comment


            #6
            Re: Graco ST MAX II 495 PC PRO , paint spray machine help

            Yes unfortunately

            Customer took it upon himself to replace D16 , so now i need to try & discovered part number of original.

            C20 on my to do list as well .

            Comment


              #7
              Re: Graco ST MAX II 495 PC PRO , paint spray machine help

              Originally posted by zen View Post
              Thanks

              16X297 seems to be the PCB number .

              Quite funny when i type it into Google . A repair kit popped up , which is the whole board , at a cost of £370
              There`s some new boards on alibaba https://www.alibaba.com/product-deta...620074426.html ,it doesn`t mention how much the shipping would cost though.
              All donations to badcaps are welcome, click on this link to donate. Thanks to all supporters

              Comment


                #8
                Re: Graco ST MAX II 495 PC PRO , paint spray machine help

                Thanks , still battling with this one .

                U7 ( VIPER 12A ) control chip also seems to be faulty .


                D16 is fed from a transformer ,then follows through R17 which is cooked , then to the supply pin 4 ( VDD ) of U7 .


                Only 2 pins of D16 are actually connected , therefore assume it's some sort of fast switching rectifier diode .


                Can anyone help with replacement advice for D16 ,& also value of R17 , which i assume will be quite low .
                Attached Files
                Last edited by zen; 06-24-2022, 08:51 AM.

                Comment


                  #9
                  Re: Graco ST MAX II 495 PC PRO , paint spray machine help

                  The component installed at D16 now seems to be a transistor (BCR162) any sot23-3 200ma or higher diode should work. Many circuits use a 1N4148 for this diode, so find a similar SOT23-3 (BAT54, BAT54C)
                  The resistor could be anything low 0~10Ω maybe
                  Last edited by R_J; 06-24-2022, 09:54 AM.

                  Comment


                    #10
                    Re: Graco ST MAX II 495 PC PRO , paint spray machine help

                    Thanks RJ , yes that was the customer messing about with it .

                    Was thinking around 10R myself .

                    Comment


                      #11
                      Re: Graco ST MAX II 495 PC PRO , paint spray machine help

                      D16 is usually a SOT-23 diode like BAV99, BAS16, MMBD4148 etc. I think BAT54 at 30V is too low. Around 10R looks reasonable for the resistor. C20 must be in bad shape.

                      What fused? A shorted Viper 12 usually blows the top off, and this board has pretty thin pcb traces and looks 4-layer. Many scuffs and nicks on traces/solder mask. Even parts are trashed, R7, U11- could you use a bigger hammer.
                      I'd check with an ohmmeter the path from primary cap to transformer to see if there is an open-circuit. I don't see what fused yet.
                      There's no feedback opto either, so it might not be an isolated supply.
                      Viper 12 datasheet

                      Comment


                        #12
                        Re: Graco ST MAX II 495 PC PRO , paint spray machine help

                        Originally posted by R_J View Post
                        The component installed at D16 now seems to be a transistor (BCR162) any sot23-3 200ma or higher diode should work. Many circuits use a 1N4148 for this diode, so find a similar SOT23-3 (BAT54, BAT54C)
                        The resistor could be anything low 0~10Ω maybe
                        The bat54 voltage is a bit low, go for something around 100v

                        Comment


                          #13
                          Re: Graco ST MAX II 495 PC PRO , paint spray machine help

                          Hi Redwire ,the scuffs are due to all the hardened glue i needed to removed so that i could gain access to many of the components .

                          Cheers on the advice for diode type guys , will check to see what i have in stock .

                          Comment


                            #14
                            Re: Graco ST MAX II 495 PC PRO , paint spray machine help

                            All that messing about , then customer pulls repair

                            Comment


                              #15
                              Re: Graco ST MAX II 495 PC PRO , paint spray machine help

                              I understand the conformal coating can make the repair extra hell. I use needle probes to poke through for readings, and hot air gun to heat/soften the coating and scrape it off.
                              TBH the board is a piece of junk, nobody puts a MCU ceramic oscillator right next to the SMPS primary. Skinny traces and more glue please.

                              Customer seems to keep trying people to repair it for $0.99 or something. If someone already was in there, I don't take on the repair because it can be such a mess.

                              Comment


                                #16
                                Re: Graco ST MAX II 495 PC PRO , paint spray machine help

                                Thanks for the additional info Redwire .

                                I normally pop board onto my pre heater to loosen the glue , but this was quite hard heat resistant stuff & couldn't poke the meter probes through .

                                Next one i see ,cost will double

                                Comment


                                  #17
                                  Re: Graco ST MAX II 495 PC PRO , paint spray machine help

                                  some conformal coating disolves with white spirit.

                                  Comment


                                    #18
                                    Re: Graco ST MAX II 495 PC PRO , paint spray machine help

                                    Great tip STj , will try that next time .

                                    Comment

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