🔴 #620 MagicTV MTV3600TD-NZ Repair Attempt – Can I Fix It ?

16 Comments

1. Jason J on October 5, 2020 at 10:54 pm

   Is this one of those boxes which run all live TV through a buffer on the hard drive? If so the drive could be getting a bit marginal and glitching results due to re-seeks. If the drive is a standard format it might be worth formatting a spare drive to work with it and testing with that.

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2. Ben C on October 5, 2020 at 10:58 pm

   6th

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3. Capposteve on October 5, 2020 at 10:59 pm

   That’s normally down to signal strength of the incoming signal. My sky does it sometimes

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4. Thomas W on October 5, 2020 at 11:00 pm

   Bad sectors ?

   Small caps have higher esr than big ones.

   Smd al caps tend to explode on hot air. Wear goggles

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5. Amir B on October 5, 2020 at 11:01 pm

   I think this issue is most likely either a CPU or memory problem. I would have actually started by reworking the memory and flash chips (quality flux + heat gun). I have repaired similar hickups in other instruments by doing this. After that, maybe reworking the CPU itself if that is possible. It’s weird, these kind of glitches are very hard to repair unfortunately. Good luck !

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6. Paul on October 5, 2020 at 11:10 pm

   I reckon it’s the tuner

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7. bigt on October 5, 2020 at 11:16 pm

   The problem you have is not the TV most likely problem with the signal coming from the recorder ie tuner cercuit has it is afecting both play back and record.cheers very old TV and Video engineer .UK

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8. Jayy Tee on October 5, 2020 at 11:19 pm

   Have you checked your antenna and associated cables and plugs?
   Also nearby electrical interference?.

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9. Amir B on October 5, 2020 at 11:21 pm

   There was no need to change those caps, they were all fine. SMD caps usually have high ESR and specially so at 100Hz, look at their datasheets. If you check at 1Khz or 10Khz you’ll see they are fine.
   As for removing them, I never use hot air because if the caps are gone bad or leaked, they will explode very quickly and can be even dangerous (been there before!). When they are not bad, they come off easily and dont explode. The best way I found to remove them is just by soldering iron and little bit of SMD-1 Chipquick solder. It works magic and not only for SMD caps, for many SMD parts.

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10. zx8401ztv on October 5, 2020 at 11:23 pm

    Hmm if it glitches while watching live then tap the top of the tuner tin, you could have a dodgy joint inside.

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11. Helmuth Schultes on October 5, 2020 at 11:23 pm

    One issue that seems to arise on the digital systems is that it appears, especially on older systems, that the MPEG coding appears to have some subtle changes in the last year or two. This image break up seems to occur on old decoders, and the hardware Sigma chips hae been related, occurs especially on loud audio sections of latest DVD, Blurray and TV broadcast signals. If there is no update possible or not done, then in very recent times breakup comes ever more often. My Samsung TV last year got bad on new release movies on TV channels, but became perfect after a software update. In last few months it has atarted again on movies like the latest Marvel series. Last week on the two newest ALIEN ones that were broadcast. As my TV is currently not on LAN I have not yet tried software revision update. The same movies played via my BLUE ray player are fine. TV playback other than the movies is unaffected, leading to suspicion of MPEG code changes affecting older decoders under some circumstances, given the fix after software update last year. Also the SIGMA chips on an very old PC MPEG card, must be 2000 or older, does not work on programs newer than about 7 years, but plays very old DVD and older Video CDs. That is silicon chips no possible. It is quite possible there is no fix.
    Another opportunity of problems is the HD data may have flow problems as disc reading gets slowed by progressive reading iss issues, slowing data bit rates enough to delay MPEG data falling behind needed decoder input. There may not be sufficient buffering. As HD heads deteriorate sectors may need to be re read several times to get correct data. Thus several revolutions delayed. Is it possible to evaluate HD issues using a spare HD to record fresh programs. On a PC such HD problems cause slower operation and over time permanent bad spots and drive fails. PC dianostics can normally read back drive diagostics showing buildup of these progressive error rates

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12. Anton * on October 5, 2020 at 11:29 pm

    Places to look are input circuitry, CPU power, and the CPU itself. You could try to think of a way to isolate the problem. For instance, inject a signal bypassing some circuitry, check the recording on a different device (to eliminate the possibility of output circuitry issue), test with another input or output. Also you can try flexing the board while it’s on and watching for correlation between flexing and image distortion. If there is correlation, the problem is likely in some BGA chip or the balls underneath it. It could be a ram issue as others said, too. Ram also may have a broken solder ball, in which case reflow may help.

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13. Orbiter Electronics on October 5, 2020 at 11:30 pm

    Unlucky with this one Scott. Unfortunately we can’t fix’em all mate.
    Regards
    John

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14. Ray Welshman on October 5, 2020 at 11:32 pm

    Hi Scott, look at the HDD date code 07 Oct 2010, maybe box manufacture late 2010 or early 2011, so it is getting old in the tooth, just like me..
    Regards, Ray North West Wales..

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15. Mario Riesebeek on October 5, 2020 at 11:45 pm

    Please check the antenna input. Clean it, and resolder it. Looks like signal problem

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16. Ryan Michael Upton on October 5, 2020 at 11:45 pm

    Yeah this is a RAM problem. You need to replace one of the four RAM chips, maybe the one with black texter on it.

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