RCA VCR MODEL VMT-400 Problem

Collapse
X
Collapse
+ More Options
Posts
 
  • Time
  • Show
Clear All
new posts
  • ALPUG60
    Member
    • Feb 2018
    • 21
    • USA

    #1

    RCA VCR MODEL VMT-400 Problem

    Hi all this is a shot in the dark...but VCR loads...but no other functions. The main capstan motor which controls most functions does not activate. Motor checks out good. Maybe someone has circuit board location , and common cap problems. Its been a long time without use...Thanks Al
  • R_J
    Badcaps Legend
    • Jun 2012
    • 9535
    • Canada

    #2
    Re: RCA VCR MODEL VMT-400 Problem

    The first thing to check is the belts, the loading belt could be bad an not loading completely. Provide some pictures of the mechanism. This vcr is over 30 years old
    Last edited by R_J; 03-25-2020, 10:41 AM.

    Comment

    • ALPUG60
      Member
      • Feb 2018
      • 21
      • USA

      #3
      Re: RCA VCR MODEL VMT-400 Problem

      Thanks for reply RJ.....All belts are good. Capstan motor on top of large pulley, controls almost everything (play, ff, rew) It is not engaging after tape rollers pull the tape to head..therefore rollers pull back to position and unit goes to STOP.
      Two pics enclosed...Thanks Al
      Attached Files

      Comment

      • R_J
        Badcaps Legend
        • Jun 2012
        • 9535
        • Canada

        #4
        Re: RCA VCR MODEL VMT-400 Problem

        Make sure the loading motor is loading the tape all the way, Those two small belts on the loading motor could be slipping and not loading fully. If the tape does'nt load all the way, it will time out and unload.
        If you grab the belt and pull it away from the pulleys, it should snap back. Those belts usually get like gum and when stretched, slowly shrink back.
        Does the video drum start up when the tape is loading?
        Also check the voltages coming from the power supply, they should be marked on the board near the plug.
        It could also be that the mode switch needs cleaning, these switches were usually ok but after sitting this long the contacts could be tarnished.
        Those pictures are too small (400x300)
        Last edited by R_J; 03-25-2020, 08:32 PM.

        Comment

        • ALPUG60
          Member
          • Feb 2018
          • 21
          • USA

          #5
          Re: RCA VCR MODEL VMT-400 Problem

          The video drum does not rotate. The loading motor is the only motor working...The tape up rollers go all the way up ( belts are good) When rewind and ff is pressed the clutch moves to proper spindle but does not turn ( since the capstan motor is not functioning) I traced the wires coming to the capstan motor from the circuit board...I was hoping to find some bulging caps ....but all look good. Thanks Al

          Comment

          • R_J
            Badcaps Legend
            • Jun 2012
            • 9535
            • Canada

            #6
            Re: RCA VCR MODEL VMT-400 Problem

            Is the tape end sensor lamp, lit? These older vcr's used a small incandescent lamp.

            The drum should start spinning as soon as play is pressed and the tape starts to load, if the drum does'nt spin, the capstan motor won't be started either.

            One more thing to check is the tape end sensor lamp, if this lamp is open I believe it can cause this.

            Check that all the fuses are ok on the power supply, You could be missing (If I remember) 9 or 12 volts. If I recall there is a stxxx ic on the power supply that outputs a couple different voltages.
            Attached Files
            Last edited by R_J; 03-27-2020, 07:28 PM.

            Comment

            • ALPUG60
              Member
              • Feb 2018
              • 21
              • USA

              #7
              Re: RCA VCR MODEL VMT-400 Problem

              The lamp is infrared...impossible to tell if lit. But if the lamp was burnt out I don't think the tape up rollers would pull the tape to the head. The 3 power line fuses all check good. I traced harness from video head motor to circuit board, and no bulging caps. Do you believe the capstan motor would not function if the video head don't turn? It is very difficult to check voltages from power supply, without pulling half the set apart. Where would I find the mode switch? Thanks Al

              Comment

              • R_J
                Badcaps Legend
                • Jun 2012
                • 9535
                • Canada

                #8
                Re: RCA VCR MODEL VMT-400 Problem

                The power supply should lift out, there may be one or two screws holding it in place. I guess I was thinking of an older model that used the lamp for the end sensor, this must be new enough to have the IR emitter.
                The drum starts before the tape is loaded, because if you wrap the tape around the drum before it starts, it likely won't start due to the tape wraped around it, or if it does start it will grap the tape an pull it from the cassette.
                The only time the capstan motor starts is in Play, FF or REW. or when stop is pressed and the tape is being wound back into the cassette
                As for the mode switch, I can't tell from the small picture, it is on the bottom, near the loading motor
                Attached Files
                Last edited by R_J; 03-28-2020, 02:37 PM.

                Comment

                • ALPUG60
                  Member
                  • Feb 2018
                  • 21
                  • USA

                  #9
                  Re: RCA VCR MODEL VMT-400 Problem

                  Yes, you were correct. The P/S came out with 2 screws. I measured AC going in (120v) and out of transformer are 9 pins. They all show DC current measuring from 28v-10v. So it seems the DC is going out. Unlike schematic, there are no voltages noted on circuit board. Thanks AL

                  Comment

                  • ALPUG60
                    Member
                    • Feb 2018
                    • 21
                    • USA

                    #10
                    Re: RCA VCR MODEL VMT-400 Problem

                    I checked voltage to capstan motor...and none is present. Harness to drum motor has 12 pins...getting 10.6 v on 3 of them nothing on others. Mode switch is working properly. Do you think anyone might have schematic? If not, it might be time to say good-bye. In any event thanks TJ for all your help and stay safe!
                    AL

                    Comment

                    • R_J
                      Badcaps Legend
                      • Jun 2012
                      • 9535
                      • Canada

                      #11
                      Re: RCA VCR MODEL VMT-400 Problem

                      With just the tape loaded, rewind and fast forward should work without the drum spinning.
                      The capstan motor circuit should not be too complicated, The drum uses a 3phase motor with phase generator for speed control.
                      As for a service manual, I doubt you will find a pdf of it, someone might be selling a paper version. I would have had the service manual at one time but it is now likely a paper plate or toilet paper.
                      The closest service manual I could find would be for a hitachi vt33e It might help.
                      Last edited by R_J; 03-31-2020, 04:16 PM.

                      Comment

                      • R_J
                        Badcaps Legend
                        • Jun 2012
                        • 9535
                        • Canada

                        #12
                        Re: RCA VCR MODEL VMT-400 Problem

                        On the Hitachi model, the capstan motor drive ic is on the power supply module. The RCA model might be similar. Like I said, without good pictures, it is hard to help.
                        Last edited by R_J; 03-31-2020, 08:22 PM.

                        Comment

                        Related Topics

                        Collapse

                        • sbt123
                          charnwood w821 mini wood lathe motor problem
                          by sbt123
                          hi there,im having a look at repairing a wood lathe for my dad,(charnwood w821)the problem is when turning up the variable speed control,the motor starts to stop and start by itself,if i continue to turn up the speed it will trip the mcb in the consumer unit,there is also a slight smell of burning from the speed controll box.,Another strange symptom is the lathe can be unplugged from the mains after switching it off and the motor will spin a couple of times by itself,so far ive put a new speed controll potentiometer on and new motor brushes,ive also tested the motor windings and everything looks...
                          10-27-2024, 03:43 AM
                        • theone111
                          Problem with LG Plasma 60PM6700 - Random power downs
                          by theone111
                          I have an LG Plasma TV 60PM6700 for the past ~12 years.

                          In the last ~3-4 months I have been having some issues.
                          1. Problem: It started with random picture disappearing (sound still worked).
                            Frequency: Happened about once a week.
                            Solution: Had to turn off TV wait a few seconds before turning it on again.
                          2. Problem: Then it got worse and the TV started to shut down and when turning on the no picture just sound.
                            Frequency: Happened about once a week.
                            Solution: Had to turn off TV wait about 10-20 seconds and turn it on again to solve.
                          3. Problem: TV shuts down
                          ...
                          07-22-2024, 10:36 AM
                        • Zeonalbasta
                          Thinkpad X1 Carbon "LMQ-1MB 12298-2 48.4LY26.021" VCC3M problem
                          by Zeonalbasta
                          i have a problem with thinkpad X1 carbon gen 2 "LMQ-1MB 12298-2 48.4LY26.021"
                          The laptop was turned off because the MOSFET was not transmitting voltage. After checking it turned out that the gate pin on the MOSFET was the problem, because it was producing an inappropriate voltage. and it was discovered that the problem was with the Think engine, so I decided to reprint each pin, and finally the mosfet could work properly. However, there is another problem, even though the voltage has been supplied to the laptop, it still won't turn on, there isn't even an LED indicator. After double...
                          09-13-2024, 01:17 PM
                        • juergenb
                          Nescafe Aeroccino, still fails with new Motor (red flashes only once)
                          by juergenb
                          Hi,

                          i am asking for some Help.
                          I have one of these Nescafe Aeroccino (Milk Frother) things with a bad motor.
                          The Motor didnยดt start anymore and internet is full of users just swapping the motor for a Mabuchi RF-500TB-12560.
                          So i got a few of these from Banggood.

                          I swapped the motor and now i have a new fault condition.

                          In a working Frother you would press the start button, it will light red and work for a few minutes.
                          If you press longer it will light blue and just mixup the milk.

                          With the new Motor it just starts...
                          03-23-2021, 11:24 AM
                        • Gibon378
                          Problem with stopping audio and video for no reason
                          by Gibon378
                          PC Specs:
                          • CPU: Ryzen 5 1600
                          • GPU: GTX 1080 Palit JetStream
                          • MOBO: ASRock ab350 PRO4
                          • RAM: Crucial Ballistix Sport 2x8GB 3000MHz (XMP 2.0)
                          • PSU: XFX 650W (don't remember what model)
                          • OS SSD: ADATA SP920
                          • OS: Windows 10 21H2


                          Problem description:
                          Hi. I have a problem that has been going on for some time (2-3 years). It's hard to explain what it really is. Sometimes, my computer stops playing music, stops videos (starts buffering on youtube), there is no sound in games and when I minimize the game window and return to the game there is a black screen with window borders...
                          11-19-2022, 09:41 AM
                        • Loading...
                        • No more items.
                        Working...