Hitachi HDR505 - no antenna signal

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • jarsudsco
    Member
    • Mar 2014
    • 28
    • UK
    #1

    Hitachi HDR505 - no antenna signal

    I have an Hitachi HDR505 Freeview+ Recorder. It uses a Vestel 16MB835N-4 T385 041109 PCB.

    It powers up ok and can access the existing recordings on the HD, but it reports there is no antenna signal - so re-tuning results in no channels found, and there is no signal at the aerial output socket (JK2) with a known good aerial connected to the input (JK1).

    I have tried re-touching the solder on those discrete components obviously in the signal path from JK1 to the tuner IC's (? MXL5007T) and back out to JK2 with no success.

    Any suggestions on what to try or test next would be very welcome.

    Regards,


    - jarsudsco
    Attached Files
    Tags: None
    • tom66
      EVs Rule
      • Apr 2011
      • 32560
      • UK
      #2
      Re: Hitachi HDR505 - no antenna signal

      Check the +35V from the PSU is OK. This is used to tune the tuner.
      Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
      For service manual, schematic, boardview (board view), datasheet, cad - use our search.

        Comment

        • jarsudsco
          Member
          • Mar 2014
          • 28
          • UK
          #3
          Re: Hitachi HDR505 - no antenna signal

          @tom66 - Thanks for the quick reply. The external PSU is only 12V so I guess the 35V must be generated on the board but I can't even see any capacitors rated greater than 25V - would you happen to know where I could check?

          Regards,


          - jarsudsco

            Comment

            • tom66
              EVs Rule
              • Apr 2011
              • 32560
              • UK
              #4
              Re: Hitachi HDR505 - no antenna signal

              It might be of a different design. What is the part # of those ICs near the tuner input?
              Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
              For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                Comment

                • jarsudsco
                  Member
                  • Mar 2014
                  • 28
                  • UK
                  #5
                  Re: Hitachi HDR505 - no antenna signal

                  The two smaller chips nearest the jacks are both marked MXL5007T the two larger chips beneath are both marked D61541GB.

                    Comment

                    • jarsudsco
                      Member
                      • Mar 2014
                      • 28
                      • UK
                      #6
                      Re: Hitachi HDR505 - no antenna signal

                      Does anyone happen to have or know where I could find a proper datasheet for the chips I mentioned above - MXL5007T? They appear to be made by Maxlinear but everytime I think I've found a datasheet it turns out to be really just a sales brochure. I've found one image sort of showing the pinouts but it's such a poor image I can't actually read the writing.

                      Cheers,

                      - jarsudsco

                        Comment

                        • tom66
                          EVs Rule
                          • Apr 2011
                          • 32560
                          • UK
                          #7
                          Re: Hitachi HDR505 - no antenna signal

                          A lot of those parts don't actually have full public datasheets unfortunately, they are considered proprietary. Not much you can do about this except look for training manuals/schematics/etc.
                          Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
                          For service manual, schematic, boardview (board view), datasheet, cad - use our search.

                            Comment

                            Previous template Next

                            Related Topics

                            Collapse
                            • Phil289
                              Bush eled32240fhdcntd3d - no aerial signal
                              by Phil289
                              Hi
                              Could somebody guide me as to what to check next?
                              This tv has slowly become harder and harder to pick up a signal from the aerial.
                              Sometimes if i leave it on long enough it will find all the channels and work great until the next cold boot.
                              Ive tryed another tv in the same aerial socket and it works fine.
                              Ive tryed the ‘faulty' tv in another working aerial socket and it doesn't find any channels at all.
                              There's no looseness to the aerial socket on the tv and checking inside on the power board and mainboard there's nothing obvious to see - its all...
                              12-02-2022, 01:54 PM
                            • AstutePauciloquent
                              Requesting Help For GA-970A-DS3 rev. 1.0, No Post code, no RSMRST# signal
                              by AstutePauciloquent
                              Hi everyone, over the past few months i have taken a deep dive into motherboard diagnostics and I love the challenge. Currently im trying to learn all about the signals that travel around the motherboard, such as frequencies, enable signals High and Low logic states etc. And i have been learning to read and using the Schematics for this board that i requested here on Badcaps forum, from a few months ago, this is such a great place for these.

                              I’ve been working on a GA-970A-DS3 (rev. 1.0) that does not post. This motherboard has been my main learning board. I would like share...
                              11-23-2023, 11:02 PM
                            • howardc64
                              Vizio M65Q7-H1 Red Vertical Strips fixed by tape blocking LC1 signal to half of the panel
                              by howardc64
                              Failure Symptom



                              No picture, just red vertical stripes. Google search shows quite common problem for these recent Vizio M series although red vertical stripe pattern may differ. Some call it "Netflix" boot screen haha.

                              Where is the short?

                              Panel has 4x buffer boards. Quickly found the 1/4 panel buffer board with the problem by selectively disconnecting buffer board flex cables.



                              Having recently fixed another Vizio with similar symptoms that was a shorted ESD diode array ( link ) Probed the ESD diode array but...
                              05-27-2025, 02:56 PM
                            • Chaks
                              Ground Plane For 5dBi ISM Band 865-870Mhz Embedded Ceramic Antenna
                              by Chaks
                              TAOGLAS ANTENNA MODEL: ISPC.86A.09.0092E

                              The specs says ...
                              High antenna efficiency 868MHz ISM Band
                              5dBi Peak (when placed on 30cm x30cm ground plane) - Broadside to Zenith Radiation Pattern

                              The antenna is 50x50 mm square and How do I fix it on the Ground Plane of 300 x 300 mm (aluminium sheet 3mm thick).

                              1. Should I Fix it with a glue.
                              2. Should I fix it with a double side adhesive tape
                              3. Should I fix it with Screws (the screw head may just clamp the antenna to the aluminium...
                              12-09-2024, 11:06 AM
                            • JayPoorJay
                              Converting +/- 5v to a Usable Hz Signal
                              by JayPoorJay
                              Good morning.

                              I have posted here before and have gotten AMAZING advise (thank you!). I'm back for more. This BCaps Sub Forum is so well attended I thought I would post here.

                              This question is for an automotive application but has to do with what are essentially electrical questions and problem solving... If this is inappropriate I get it. Feel free to delete it or move the question.

                              The V 12 Jaguar XJS is notorious for overheating in stop and go traffic in hot weather... Y'all will be potentially helpinh a LOT of people. The solutions and directions...
                              08-07-2022, 08:35 AM
                            • Loading...
                            • No more items.
                            Working...