Doric Reddifusion MK 4 second set repair video

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  • Опубліковано 29 жов 2024

КОМЕНТАРІ • 72

  • @johnrudd9550
    @johnrudd9550 2 місяці тому +7

    I sold quite a few of these mk4 sets bought from the ex rental sellers of that time, great sets to work on and produced decent pictures..thanks for the video.👍

  • @marksntl7632
    @marksntl7632 2 місяці тому +1

    Most Excellent! Thanks for sharing! I do recall these sets. However, mostly due to when working for a company around 1984/85 when the owner purchased a bulk lot of brand new boxed old reserve stock from the Redifusion / Granada warehouse, when they wanted to empty it of these models. I not entirely sure of how many he purshased for resale, it would of been in at least batches of several hundred at a time, but not sure how many batches in Total. Although some did appear in workshop for repair, it wasn't many, so I guess they were pretty reliable when new (although would of been the last run from the factory I guess, with any production mods put in place). I never got to look at another one again after leaving that company, when by then they would of all been over a year or two old. But we had little or no trouble with them for a year or two from new....

    • @michaeldranfield7140
      @michaeldranfield7140  Місяць тому +1

      I dont think these sets had many common faults back then unlike Thorn stuff so as you say pretty good for reliability , I think the continental crt in some models were the biggest let down .

  • @jimmacdonald9746
    @jimmacdonald9746 2 місяці тому +10

    Great to see someone who knows what needs doing . Brilliant 🇬🇧👍🏻

  • @kendom33
    @kendom33 2 місяці тому +5

    Absolutely top work Michael. As I've said before you are a wizard on electronics. Great respect to you

    • @michaeldranfield7140
      @michaeldranfield7140  2 місяці тому

      Repairing older TV s was a lot easier than trying to fault find modern stuff where there is no service manual .

  • @kjellnilsson1615
    @kjellnilsson1615 2 місяці тому +1

    Hi mr, Dranfield ! I have recently bye a Atlas DCA 55 semiconductor Component Analyser !! And are very impressed how easy it is to work with ! And a very good manual,, thath explains how to use , and how it's work ! Are very impressed off this little clever device !! I have even a Atlas ESR + Low resistance capasitance meter ! That works really good too !!

    • @michaeldranfield7140
      @michaeldranfield7140  Місяць тому

      they are designed by my friend Jeremy , I have supported him ever since he started, in fact on my youtube channel I did a video on his very first design that was originally published in everyday electronics magazine many years ago , his place is only just down the road from me , everything is made in England .

    • @kjellnilsson1615
      @kjellnilsson1615 Місяць тому

      @@michaeldranfield7140 that Gay must be a real Genius ! But so are you ! I am amazed by your skill to make the most difficult tv back to life ! And are also stunned by your big storage of all parts in stock ! You have components for big money in your possess !! Must be a good feeling ,, only take a walk to your stach,,,and find what you looking for !! And all dokuments you have for the most Tv models ! You are the best in your field to find any foults !👍👍👍👍👍 Keep up the good work !! Kjell from southern Sweden .

    • @kjellnilsson1615
      @kjellnilsson1615 Місяць тому

      @@michaeldranfield7140 England has always too my novlignes been very good at electronics , just like the Danish ! The Bang & Olufsen make great stuff,, but cost a great price tag , but the only use the best components available , and make circuit bords in Army quality ! With massive Cooper lines , thath not exape , when you hit it with a solder Iron !!

  • @matthewgriffin4761
    @matthewgriffin4761 2 місяці тому +1

    Keep up the good work Michael and thanks for another great video.

  • @007mrdarcy
    @007mrdarcy 2 місяці тому +9

    Fantastic job Michael. I absolutely love the forensic fault detection and logical approach that a good technician needs to mend such complex electronics, TVs these days are flimsy little boards that can be whipped out and replaced rather than mended. Good to see you're still enthused by achieving a successful repair.

  • @jimsimpson1006
    @jimsimpson1006 2 місяці тому +3

    Nice job Mr. Dranfield. Always a pleasure to watch a guy with decades of experience who really knows what he's doing with this old technology.

  • @ronroberts34
    @ronroberts34 2 місяці тому +6

    Excellent work - really enjoyed watching that. When I was a kid we had a rediffision tele, ours was a cable TV set - before cable TV (as we know it now!) existed. Keep those videos coming and old fashioned electronic repairs alive.

  • @tubeDude48
    @tubeDude48 2 місяці тому +5

    Thanks for your time! 😄

  • @robtitheridge9708
    @robtitheridge9708 2 місяці тому +1

    excellent video as allways .i have never come across an OC common mode choke befor.

    • @michaeldranfield7140
      @michaeldranfield7140  2 місяці тому

      I have come across the odd one in cheap LCD sets where conductive glue has attacked the enamel but this one had no glue in the area where it had blown , very strange .

  • @truthreigns7
    @truthreigns7 2 місяці тому +1

    Thank you Mr Michael

    • @michaeldranfield7140
      @michaeldranfield7140  2 місяці тому +1

      no problem , many thanks for watching .

    • @truthreigns7
      @truthreigns7 2 місяці тому

      @@michaeldranfield7140 you do teach me a great deal.

    • @truthreigns7
      @truthreigns7 2 місяці тому

      @@michaeldranfield7140 I have learned a great amount from your channel

  • @walker55able
    @walker55able 2 місяці тому +5

    brilliant work Michael

  • @andic6676
    @andic6676 Місяць тому +1

    Used to love these sets! They looked ancient but they had auto greyscale tracking and were really reliable. The tripler was a weakness with these.

    • @michaeldranfield7140
      @michaeldranfield7140  Місяць тому

      Hoping the customer doesn't want the old tripler back, I can use the case to make another one .

  • @Chris558576
    @Chris558576 2 місяці тому +1

    Thank you for this. I owned a couple of these in my previous home & liked those sets

  • @martinb2553
    @martinb2553 2 місяці тому +2

    I remember those sets well when I worked at Granada . We used to stick Granada stickers over the rediffusion sticker ! Great video

    • @michaeldranfield7140
      @michaeldranfield7140  Місяць тому

      I remember some sets had a blue Granada label stuck on the back .

  • @proluxelectronics7419
    @proluxelectronics7419 2 місяці тому +3

    Its amazing how very few today will see real electrons doing magical things. Glad I lived in an age of learning instead of complaining. 👍

    • @michaeldranfield7140
      @michaeldranfield7140  2 місяці тому

      Me too, so many happy memories of years gone by that will not be coming back now , component level fault finding is a thing of the past .

  • @paulsanderson8804
    @paulsanderson8804 2 місяці тому +2

    Brilliant. TV autopsy Michael. I hope the customer enjoyed. Paying his bill. As much as you enjoyed fixing the set.

    • @michaeldranfield7140
      @michaeldranfield7140  2 місяці тому +1

      I love these old sets now , so simple to repair compared to todays stuff.

  • @markpirateuk
    @markpirateuk 2 місяці тому +1

    I remember the Mk4 as being a good set, like you, I have not seen one for many years, you did a great job finding the Fault with those nasty AV sockets, it is always a pain when someone has already been in there!

    • @michaeldranfield7140
      @michaeldranfield7140  2 місяці тому

      not sure why they replaced the AV sockets but they fitted a worse one than the one they took out !

  • @anthonylyons9810
    @anthonylyons9810 2 місяці тому +3

    Hi Michael, I bought the 22 inch version back in the Summer of 1984. It was hard to adjust the Brightness and Contrast Settings to produce a Good Picture. Watching a Football Match for example. If part of the Pitch was in Shadow because of the Stand, , The Players , Ball etc, would disappear. Adjusting the Brightness and Contrast Setting to eliminate the problem caused the picture to be to Bright on Other Scenes. Rediffusion made many a call to resolve the problem to no avail. I sold the Set 4 Years later and bought a 21 inch Sony Black Trinitron 211XMT that displayed excellent pictures for 20 Years without a Service Call.

    • @michaeldranfield7140
      @michaeldranfield7140  2 місяці тому

      nothing to beat a sony trinitron , they were legendary and used by television broadcast companies who would only buy the best.

  • @michaelwaite6725
    @michaelwaite6725 2 місяці тому +3

    Another one restored to working order , think the board you salvaged the black coil from might have been from a Decca 160 chassis they had tuning pots direct on the board

    • @michaeldranfield7140
      @michaeldranfield7140  2 місяці тому

      the Decca 160 was a much smaller board , there was another Decca I have long forgotten about and I seem to think it was a 130 where the PCB board was mounted vertically but as it happens I think I have one of these so should be able to confirm in a later video .

  • @peterc1445
    @peterc1445 2 місяці тому +1

    Made in Rochdale before factory closed i presume, Granada took over the rental side and Robert Maxwell took the broadcasting rights Maxwell communications, Almost all council housing in Rochdale had Reddifusion piped tv was told these house could not have outside Aerials as the council was under some legal contract ?, many overseas commonwealth countries used Reddifusion cable transmission .

    • @michaeldranfield7140
      @michaeldranfield7140  2 місяці тому

      I have heard of these reddifusion cable sets but never seen one as we never had cable here .

  • @douglashoff95
    @douglashoff95 2 місяці тому +2

    The shop where I worked before I retired would keep the service manual out of the file after using it for one repair because almost always another set just like it or similar would show up for repair. I see that holds true for you, also!

    • @michaeldranfield7140
      @michaeldranfield7140  2 місяці тому

      30 odd years ago this did hold true and it wouldn't be long before the next one came along but today this was a very rare occurrence seeing another one of these again .

  • @stevesje71
    @stevesje71 2 місяці тому +1

    Excellent job Mike. It seems those triplers fail quite often. I’ve repaired 5 cub monitors all with those type of triplers that had a varying EHT and focus voltage

    • @michaeldranfield7140
      @michaeldranfield7140  2 місяці тому

      the plan if the customer doesn't want the old Tripler back is to break it open and see what's gone wrong and if the old casing can be used to build another unit , its easy enough to make another tripler but the high value potential divider resistors present a bit of a problem .

    • @stevesje71
      @stevesje71 2 місяці тому

      @@michaeldranfield7140 thinking about the failures I had, it was all related to varying focus voltage. The potentiometer was fully over to one extreme to obtain good focus, but as it warmed up it would gradually change. I found a OE supplier of NOS and it’s been fine ever since

  • @mrnmrn1
    @mrnmrn1 2 місяці тому +2

    Any RIFA paper X and Y capacitors in anything should be replaced on sight, including the previous Reddifusion. That green goo in the Siemens common mode choke supposed to be epoxy, but some batches came with this goo instead.
    I have a Grundig V2000 VCR with this same style of Siemens choke in which that goo become so runny that in covered half the PSU board over the years. Either the epoxy somehow chemically broke down over the years, or it was a bad mixture to begin with. Thankfully it seems like non-corrosive, but it's still not desirable, especially if it leaks inside trimpots, as it did in my VCR.

    • @michaeldranfield7140
      @michaeldranfield7140  2 місяці тому

      in years gone by I never had any problems with the RIFA caps , the problem seems to be the epoxy shrinks and cracks over time , I have a load of brand new ones in stock and most of them have cracked cases despite never seeing the light of day , perhaps its some sort of chemical reaction like in the choke as you say .

    • @mrnmrn1
      @mrnmrn1 2 місяці тому

      @@michaeldranfield7140 I had quite a few of their and WIMA's paper X capacitors exploded in Philips V2000 VCRs, my '80s Sharp microwave, and various other things, most of them were already exploded when I got them, I only experienced a few occasions in person. Yes, they age and crack during storage. They belong to the e-waste container after ~20 years, being used or brand new doesn't matter. I'm not a chemist, but I know most plastics, including epoxy is not a hermetic seal. Over years and decades, moisture from the air can ingress into the package, where it soaks into the paper which expands and cracks the package. During the process, the paper also turns acidic (or base? not sure which), and this, combined with humidity will cause high leakage currents which induces heat and the paper eventually breaks down, causing a partial short and the capacitor explodes with a stinky cloud of smoke.
      There are plenty of YT videos which documented such events during the test and repair of vintage computers and other electronics.

  • @gainmaster1
    @gainmaster1 2 місяці тому +1

    Genius

  • @f.k.burnham8491
    @f.k.burnham8491 2 місяці тому +1

    Excellent job of troubleshooting. Do you have a PC board and schematic available for your cap reformer? Thanks.

    • @michaeldranfield7140
      @michaeldranfield7140  2 місяці тому

      The orig diagram came from a magazine , I just added some extra circuity of my own , let me see if I can find it , I have a feeling it was in Everyday electronics some 20 odd years ago, might take a little while though as Im going away for my birthday in a few days but I will get back to you .

    • @f.k.burnham8491
      @f.k.burnham8491 2 місяці тому +1

      @@michaeldranfield7140 Thank You. No hurry.

    • @michaeldranfield7140
      @michaeldranfield7140  Місяць тому

      @@f.k.burnham8491 Sorry about the delay but I get overwhelmed with comments and I couldn't remember which video your request was on , ok , if you go to World radio history on the internet Its Everyday Practical Electronics July 1995, this is the basic design I just made mine a bit more complicated with automatic change over but the design in the magazine will get you started .

    • @f.k.burnham8491
      @f.k.burnham8491 Місяць тому

      @@michaeldranfield7140 Thank You

  • @lukasgayer5393
    @lukasgayer5393 2 місяці тому +1

    Green, flat cables. I smell Philips or Grundig :D

  • @leetucker9938
    @leetucker9938 2 місяці тому +1

    wow

  • @paulhubbard4838
    @paulhubbard4838 2 місяці тому +1

    Just like waiting for a bus.....

    • @michaeldranfield7140
      @michaeldranfield7140  2 місяці тому

      I know , one was a rare sight, never though I would see a second , not these days anyway .

    • @paulhubbard4838
      @paulhubbard4838 2 місяці тому

      One of note if comes your way. Sony14M1 single board chassis. Frame collapse while in storage traced to 7 pin heat sinked chip which had developed dry joints while not in use. Resolder cures all but of note its the only area of the chassis pcb that is affected with all other areas of solder up to par. Strange one that but hey ho.