2 Viewsonic VX1940W buzzing and no signal

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  • briand
    RocketScientist
    • Jan 2011
    • 12
    #21
    Re: 2 Viewsonic VX1940W buzzing and no signal

    thanks for the suggestions.

    attached is my DigiKey order... I would appreciate verification that I selected a suitable replacement for the 120uF/400V capacitor.
    Attached Files

      Comment

      • retiredcaps
        Badcaps Legend
        • Apr 2010
        • 9271
        #22
        Re: 2 Viewsonic VX1940W buzzing and no signal

        Originally posted by briand
        I would appreciate verification that I selected a suitable replacement for the 120uF/400V capacitor.
        Assuming the diameter and height are correct, Panasonic is fine.
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          Comment

          • briand
            RocketScientist
            • Jan 2011
            • 12
            #23
            Re: 2 Viewsonic VX1940W buzzing and no signal

            ...for those following along at home and/or vicariously repairing monitors through my experience, I've attached an image indicating the parts being replaced.

            C1 and C302 are definitely bad (bulged)

            C201 is questionable.

            C205, C305, and C307 are being replaced in a preventative manner, as they are of the same quality as the failed capacitors (5x CapXon, 1x VENT). All being replaced by Panasonic caps.
            Attached Files

              Comment

              • Kridian
                Member
                • Sep 2010
                • 39
                #24
                Re: 2 Viewsonic VX1940W buzzing and no signal

                Post an after pic on the new ones installed.

                  Comment

                  • briand
                    RocketScientist
                    • Jan 2011
                    • 12
                    #25
                    Re: 2 Viewsonic VX1940W buzzing and no signal

                    okay, I will.

                    life may intervene, so it may be a week or two before I get around to completing the repair.

                      Comment

                      • Neobyte
                        Learning..
                        • Jan 2011
                        • 12
                        #26
                        Re: 2 Viewsonic VX1940W buzzing and no signal

                        first msg on this great forum. Finally found this thread I was looking for. My monitor is model VX1940wm to be exact.

                        I have _exactly_ the same story as briand. Had VX922 and it was replaced to this monitor and it failed too. First time I changed only the 2 bulged caps, and the monitor worked like 1-2 month(s). After the first repair, one vertical cyan line appeared on the screen after heating up. By pressing the screen the line disappeared. Don't know it this is due some bad connection or connector.

                        Anyways, the monitor went completely dead. Decided to change all caps then and I'm also waiting the parts now. I will get back when I get it completed :P

                          Comment

                          • briand
                            RocketScientist
                            • Jan 2011
                            • 12
                            #27
                            Re: 2 Viewsonic VX1940W buzzing and no signal

                            welcome to the forum, Neobyte.

                            my parts are in-transit. Digi-Key backordered one of the caps, so I ordered it from Mouser... also found a 120uF/400V radial lead replacement (Nichicon) at Mouser as well; the Panasonic unit from Digi-Key was a 'snap-in' with two short posts.

                            I should, hopefully, have all the parts by mid-week, and have my 19" WS monitor back online by next weekend.

                              Comment

                              • Neobyte
                                Learning..
                                • Jan 2011
                                • 12
                                #28
                                Re: 2 Viewsonic VX1940W buzzing and no signal

                                Recapped the monitor now. Didn't help anymore. Must be some other component failing? Don't know what. Here's image of the smps-board..
                                It's trash unless someone figures any tricks
                                Attached Files

                                  Comment

                                  • alexanna
                                    Member
                                    • Mar 2010
                                    • 1346
                                    #29
                                    Re: 2 Viewsonic VX1940W buzzing and no signal

                                    Originally posted by Neobyte
                                    first msg on this great forum. Finally found this thread I was looking for. My monitor is model VX1940wm to be exact.

                                    I have _exactly_ the same story as briand. Had VX922 and it was replaced to this monitor and it failed too. First time I changed only the 2 bulged caps, and the monitor worked like 1-2 month(s). After the first repair, one vertical cyan line appeared on the screen after heating up. By pressing the screen the line disappeared. Don't know it this is due some bad connection or connector.

                                    Anyways, the monitor went completely dead. Decided to change all caps then and I'm also waiting the parts now. I will get back when I get it completed :P
                                    What do you mean completly dead?Have you checked all the fuses?
                                    Al.
                                    Whatever I do, I consider it a success, if in the end I am breathing, seeing, feeling and hearing!

                                      Comment

                                      • Neobyte
                                        Learning..
                                        • Jan 2011
                                        • 12
                                        #30
                                        Re: 2 Viewsonic VX1940W buzzing and no signal

                                        No power at all. Power led doesn't go on. Ermm, I found 3 fuses total, F1 (surface mount) on the 'long board', and psu-board F101 and F301. They all measured close to 0 ohms. Dunno if there's more of them? :P

                                          Comment

                                          • showmemule
                                            Member
                                            • Jan 2011
                                            • 16
                                            #31
                                            Re: 2 Viewsonic VX1940W buzzing and no signal

                                            Originally posted by wcperki
                                            The 2 Viewsonic X1940W LCD monitors I bought as a dual monitor set are both not working. They are still underwarranty but I could'nt help myself I had to take one apart. I could use some help getting the right caps ordered.
                                            I tried mouser and digikey but gave up. I'd prefer to just order from badcaps.net but here too I run into a roadblock with exact matches.
                                            I'd like to know what I can safely use to replace the following caps. Also, can anyone tell me how does one remove the epoxy glue inorder to de-solder?
                                            Pictures are attached.
                                            C1
                                            CapXon
                                            GF105
                                            P735 vent
                                            220μF 35v
                                            D=10mm x L=12mm x LEAD SPACE=5mm

                                            C302
                                            CapXon
                                            GF105
                                            P735 vent
                                            220μF 35v
                                            10mm x 12mm x 5mm

                                            C305
                                            CapXon
                                            GF 105 c
                                            P735 vent
                                            2200μF 10V
                                            13mm x 18mm x 5mm

                                            C307
                                            CapXon P735 vent
                                            KF 105c
                                            1000μF 10V
                                            8mm x 20mm x4mm

                                            C205
                                            KF105 P733
                                            50V 22μF
                                            5mm X 8MM x 3mm


                                            Thanks,
                                            Warren
                                            First make sure the caps are bad. Second you can carefully cut the glue with an exacto, avoiding board scaring, these caps you list can be found in other power supplies and controls. Just be sure to check the replacements before install. K!

                                              Comment

                                              • showmemule
                                                Member
                                                • Jan 2011
                                                • 16
                                                #32
                                                Re: 2 Viewsonic VX1940W buzzing and no signal

                                                Can someone tell me if there is an nte, or other cross number for a 13n07 mos transistor out of a dell 1704fpt

                                                  Comment

                                                  • PlainBill
                                                    Badcaps Legend
                                                    • Feb 2009
                                                    • 7034
                                                    • USA
                                                    #33
                                                    Re: 2 Viewsonic VX1940W buzzing and no signal

                                                    Originally posted by Neobyte
                                                    No power at all. Power led doesn't go on. Ermm, I found 3 fuses total, F1 (surface mount) on the 'long board', and psu-board F101 and F301. They all measured close to 0 ohms. Dunno if there's more of them? :P
                                                    The power LED is a 'fly by wire' arrangement. It is controlled by the processor on the signal (logic) card. Check the output voltage of the power supply. If that is missing, check the voltage across the large (100uF, 450 volt) cap. If the output voltage is present, check for a reset controller on the signal card.

                                                    PlainBill
                                                    For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.

                                                    Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.

                                                      Comment

                                                      • Neobyte
                                                        Learning..
                                                        • Jan 2011
                                                        • 12
                                                        #34
                                                        Re: 2 Viewsonic VX1940W buzzing and no signal

                                                        PlainBill, I tried to measure the voltages. I suppose the output is the connector going to the logic board? There wasn't much voltage present. Then I checked the large cap, the voltage was ~105V. Is that toasted too? (I did not change that during my recap operation)

                                                        edit: Btw I have 230V mains.
                                                        Last edited by Neobyte; 01-17-2011, 11:20 AM.

                                                          Comment

                                                          • retiredcaps
                                                            Badcaps Legend
                                                            • Apr 2010
                                                            • 9271
                                                            #35
                                                            Re: 2 Viewsonic VX1940W buzzing and no signal

                                                            Originally posted by Neobyte
                                                            Then I checked the large cap, the voltage was ~105V. Is that toasted too?

                                                            edit: Btw I have 230V mains.
                                                            How are you measuring that voltage across the large cap. Is that 105 AC or DC that you are measuring?
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                                                              • Neobyte
                                                                Learning..
                                                                • Jan 2011
                                                                • 12
                                                                #36
                                                                Re: 2 Viewsonic VX1940W buzzing and no signal

                                                                Originally posted by retiredcaps
                                                                How are you measuring that voltage across the large cap. Is that 105 AC or DC that you are measuring?
                                                                Black, ground from the corner screw area and red to the positive leg of the cap. My meter was at 600V (DC).. I don't have too much experience measuring these things.

                                                                  Comment

                                                                  • retiredcaps
                                                                    Badcaps Legend
                                                                    • Apr 2010
                                                                    • 9271
                                                                    #37
                                                                    Re: 2 Viewsonic VX1940W buzzing and no signal

                                                                    Originally posted by Neobyte
                                                                    Black, ground from the corner screw area and red to the positive leg of the cap.
                                                                    To measure the DC voltage across the large cap, put your black in COM and red into Volts on your multimeter.

                                                                    Then put your black probe on the negative leg of the main filter cap. Put your red probe on the positive leg of the main filter cap.

                                                                    You should get 230V x 1.414 rectified DC voltage or about 325V DC.
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                                                                    We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.

                                                                    Please do not post inline and offsite as they slow down the loading of pages.

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                                                                      Comment

                                                                      • Neobyte
                                                                        Learning..
                                                                        • Jan 2011
                                                                        • 12
                                                                        #38
                                                                        Re: 2 Viewsonic VX1940W buzzing and no signal

                                                                        Originally posted by retiredcaps
                                                                        You should get 230V x 1.414 rectified DC voltage or about 325V DC.
                                                                        Ok, I got 321V from there

                                                                          Comment

                                                                          • retiredcaps
                                                                            Badcaps Legend
                                                                            • Apr 2010
                                                                            • 9271
                                                                            #39
                                                                            Re: 2 Viewsonic VX1940W buzzing and no signal

                                                                            Originally posted by Neobyte
                                                                            Ok, I got 321V from there
                                                                            Okay, let's retest for the secondary voltages.

                                                                            Put your black probe on a screw near the connectors. This is your ground. Put your red probes on each connector (CN301) and report each DC voltage on each connector pin. Put your multimeter on 20V DC.

                                                                            edit: Pin 1, 2, and 3 according to the legend should be 5V DC.
                                                                            Last edited by retiredcaps; 01-17-2011, 12:52 PM. Reason: pin 1,2,3
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                                                                              Comment

                                                                              • Neobyte
                                                                                Learning..
                                                                                • Jan 2011
                                                                                • 12
                                                                                #40
                                                                                Re: 2 Viewsonic VX1940W buzzing and no signal

                                                                                Yes it should be 5V. Every pin shows close to zero voltage (maybe it's zero then). <0,1V anyways.

                                                                                  Comment

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