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APEX AD-1010w DVD Player repair

Discussion in 'Troubleshooting and Repair' started by Tesla, May 14, 2010.

  1. Tesla

    Tesla

    165
    2
    May 10, 2010
    It is suppose to play DVD/CD/MP3. When turned on, the power led flashes, and I can hear some ticking in the PS. None of the buttons work and the tray will not open. No video or audio output. Fuse is good.

    Would like to find a schematic. I think there are a lot of clones and many probably use the same or similar boards.

    http://www.nerd-out.com/darrenk/
     
    Last edited: May 14, 2010
  2. Tesla

    Tesla

    165
    2
    May 10, 2010
    There must be a short past the power supply. I think the quiet clicking is the PS trying to start and then shutting down over-and-over (cycling).

    When I disconnect the keypad and drive (basically everything) from the main board it still power cycles.

    When the PS is disconnected from the main board I get one quiet click only (I think it's staying on). Will try to measure output PS voltages next.
     
  3. Tesla

    Tesla

    165
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    May 10, 2010
    With everything disconnected, the PS stays on and all the output voltages look good (conveniently, they are marked on the output connector).

    On the main board, I found a small e-cap that was barely soldered in. After re-soldering it ...

    I can connect everything inside the player and the power light stays on now. PS voltages stay constant on. However, still no operation or video output. Wish I knew how to reset the processor...
     
  4. Tesla

    Tesla

    165
    2
    May 10, 2010
    The e-cap repair was nothing ... the PS is back to cycling again ... most of the time.

    Without a load on the PS (nothing connected), I always get a steady +5vDC, +3vDC, -12vDC, and +12vDC.

    Most of the time when I connect the main board it just starts power cycling. But after a while of being connected (and me turning it off/on with the power switch) it finally powers up (with the main board attached). However, if I measure the voltages then, the +3vDC is more like +2.2vDC, and the -12vDC is more like -14.5vDC ...

    Could that be normal? Or is the PS bad after all, and failing under load?
     
  5. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,192
    2,694
    Jan 21, 2010
    Failing, but kinda working after several attempts is a symptom exhibited by low ESR caps that go bad. Their ESR reduces with temperature and so after a few goes may start to marginally work.

    Whilst I can't say for certain (obviously) I would certainly be out looking for suspicious looking capacitors in the power supply.

    If, as I think you suggested, the unit worked better after the PSU was left running unloaded for a while, it adds more weight to that argument.

    The capacitor you re-soldered. Was it a manufacturing fault, or could it have been pushed away from the board by swelling of the capacitor itself?

    Also, do you know the history of this fault. Did it present suddenly, or were there symptoms prior to the complete failure?
     
  6. Tesla

    Tesla

    165
    2
    May 10, 2010
    I guess I'm going to have to just break down and get the ESR meter. All the PS caps and e-caps look good visually.

    So without a load it always works. But with a load it's boarder-line but finally allows itself to come on ... but then, the voltages are too far off ... especially to 3vdc. I think that is for the processors and maybe the memory.

    The resoldered e-cap was on the main board and near the audio/video output section (so I doubt it was anything).

    The problem with this main logic board is it's poor craftsmanship. I mean ... it's dual sided but there is just enough solder to hold the parts on. The SMT parts look fine soldered on (they only need a little). The hole-thru parts are a different story. The holes are very small, so the solder didn't flow through to the other side. They are relying on the PCBs hole-thru copper to make the connection to the traces on top. Also, to much pressure on a part can cause it to break loose from the back of the board. On the other hand ... it's very high-tech.
     
    Last edited: May 15, 2010
  7. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,192
    2,694
    Jan 21, 2010
    You said the PSU has voltages marked, it doesn't by chance have current marked as well (unlikely I guess)?

    I would measure the current drawn on each rail and see if anything sticks out.

    Generally speaking, only 1 rail is regulated (it may be the 3.3 or the 5 volt rail) and the others are left largely to their own devices. Having a low 3.3 volt rail and a high 12V rail suggests that the 3.3V rail may be under excessive load.

    It is possible that some through-hole component has broken it's solder connection, although I'd tend to think the fault would be intermittent and certainly sensitive to flexing the board (or even moving the case).

    It may be time to pull out a magnifying glass and start inspecting joints.

    edit: check the cost of replacing the capacitors in the PSU, it may be cheaper than an ESR meter, and if it looks easy and is fairly cheap, it may be worth doing anyway. Any capacitor rated for 105C, especially the low voltage ones, would be my first target.
     
    Last edited: May 15, 2010
  8. Tesla

    Tesla

    165
    2
    May 10, 2010
    Thanks.

    No, but the fuse for the whole thing is 2 amps.

    Man, I've never seen anything like this before. I guess all those inferior chinese caps had to go somewhere :eek:

    On the PS board I found 4 bad e-caps on the output or low voltage side side of the transformer. They were bulging on the bottom and some were leaking a bit (no, not glue).

    Question ... do I also replace the other 4 good looking ones on the output side? If so, do I also go ahead and replace the final 2 on the input (HV) side of the transformer (just go ahead and replace them all)?

    I've read it's sometimes good to the up the voltage a bit, but the problem is space to mount the larger ones. I hope these just failed because they were defective (they actually say China on them).
     
  9. Tesla

    Tesla

    165
    2
    May 10, 2010
  10. Mitchekj

    Mitchekj

    288
    0
    Jan 24, 2010
    Digikey is one of the more common suppliers here in the US, yeah. Reputable indeed.

    If you're looking for replacements, you'd click on the "aluminum" link under 'capacitors,' in which case you'd be given a screen to narrow down your options. Tolerance and lifetime ratings may be of importance, too.

    (Go with the Japanese, i.e. Nichicon, if possible... hehe) Though all Chinese manufacturers did not suffer from the "plague," as it were. Really interesting story there about IP theft gone wrong.
     
  11. 55pilot

    55pilot

    434
    3
    Feb 23, 2010
    Digikey generally does not cray crappy manufacturers. If they carry it, you can buy it knowing that it will at least be of decent quality.

    For single pieces, Mouser usually has lower prices and similar selection. But Digikey has a much better search interface and absolutely impeccable service. Many years ago Mouser had problems and acquired a bad reputation. In the last 5 years they have been as good as Digikey in their service.

    Both Digikey and Mouser are willing to sell very small $$ credit card orders.

    ---55p
     
  12. 55pilot

    55pilot

    434
    3
    Feb 23, 2010
    And what would that tell you? I design things professionally. My work lab has several $100K of test and diagnostic equipment and I have the authorization to buy whatever equipment I feel I need. The lab does not have an ESR meter and I have never even remotely felt the need to buy one.

    The whole notion that the first thing you need to check is the ESR of every aluminum cap in a power supply is ridiculous. If a cap has high ESR the voltage ripple will be high and it will be visible on a simple scope or even a multimeter on AC setting. If the ESR is high enough, the cap will get warm. If the ESR is too high, the cap will not only get warm but will get so hot that it will show signs of distress (bulging) or will fail completely (rupture). All of those can be seen visually.

    All that an ESR meter is good for is to separate the unenlightened from their money.

    ---55p
     
    Last edited: May 15, 2010
  13. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,192
    2,694
    Jan 21, 2010
    I disagree. Mine is a very useful tool. It allows me to test these capacitors in SMPS with the power off and everything discharged. In that respect it goes some way to satisfy your concerns of people operating on live equipment.

    If you're confronted with a pile of dead equipment and you know that high ESR capacitors are a likely problem then you can diagnose which ones can be the subject of quick and cheap attempted repair.

    And not to address the question...

    If you see some clearly affected capacitors, I would change every capacitor likely to be subject to significant ripple current. That tends to be every capacitor that is marked as a 105C (as a rule of thumb, the manufacturer has used these because the capacitors heat up in use, and that's generally because of ripple current).

    The capacitors most under stress are usually the filter capacitors on the low voltage DC side of SMPS. If there are any of these unreplaced, replace them too. Use the next highest voltage rating if there is physically room to fit them. I would not recommend using a different capacitance (some people do).

    If you have n x $100k worth of test equipment you may be able to replace less capacitors, but you can buy a lot of capacitors for $100k :D
     
  14. Tesla

    Tesla

    165
    2
    May 10, 2010
    RE: ESR Meter

    I seems to me that I can check most any component in a PS with a DMM, except the caps. I thought the options were a little $50 out-of-circuit (must unsolder to check) cap tester OR a real ESR meter (some can be tested in-circuit).

    55Pilot,
    So, you are saying that I can check e-caps in a DC circuit with the DMM set to AC? I'm guessing the circuit would have to be live? I'm not sure I would know a good reading from a bad one, but interesting never-the-less.

    I would love to have an oscilloscope to use again. When the shop/business closed down, I should have asked the owner if I could have one (or buy cheap). Nowdays, it's just a hobby ... I just hate to see perfectly good equipment going to the landfill, just because it needs $5 worth of parts and a little time.
     
  15. Tesla

    Tesla

    165
    2
    May 10, 2010
    Power Supply pics (with first 4 caps removed)

    AC Power comes in at top left white connector (currently disconnected). It immediately goes to a hard switch (next lower connector), and then to rest of board.
     

    Attached Files:

    Last edited: May 15, 2010
  16. Tesla

    Tesla

    165
    2
    May 10, 2010
    For a couple of extra dollars and minutes, I think I will just replace all the e-caps.

    All the low voltage side caps are marked 16v and 105-C. I dare not increase the uF and while I have read about increasing the voltage (and Steve mentioned) for a safety margin, I'm afraid the larger ones won't fit. Is it ok to just use 16v ones again?

    On the HV side ...

    The large one is market 47uF and 200WV ... That is Working Voltage. Is it correct that Voltage (ie 16v) and Working Voltage is the same spec? So, for this one, a 200v is fine?

    The small one is the only one in the whole PS marked 85-C (47uF 50v) ... it's ok to upgrade it to 105-C like the others, right? Increasing the temp. rating is just like increasing the voltage ... just a higher safety or durability margin?

    I'm clear on most of the selection parameters except for Tolerance (I don't see it marked on the old ones). What do you select ... for general repair of home AV equipment?

    Sorry for all the newbie questions guys. I usually just grab used parts from old boards, but if I'm going to do this, might as well do it right. I only have to be instructed/trained once (usually). :)
     
    Last edited: May 16, 2010
  17. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,192
    2,694
    Jan 21, 2010
    Yeah, it's not uncommon that the next higher voltage rating won't fit. In fact if you ever have to replace capacitors on a computer motherboard you may find that they have used capacitors smaller than you can easily purchase.

    The 200V capacitor is almost certainly filtering the rectified mains. The capacitor is charged at 50/60/100/120 Hz (depending on the rectifier) and discharged at the SMPS frequency. This usually under less stress because the ripple currents are lower.

    The problem with testing the capacitors with a DMM is that it will tell you the capacitance, which has almost certainly not changed a great deal. An ESR meter wil give you a quantifiable result that you can compare to the specs. For example a 11 ohms where the spec says 0.5.

    The replacement capacitors should be low-ESR type capacitors (certainly anything filtering the low voltage DC). I've googled for the specs in some cases, but generally if it's a 105C rated capacitor it should be low-ESR (I'm not saying that all 105C capacitors are low-ESR, but if you see them, you should replace them with low-ESR). In consumer equipment it's a pretty reliable rule of thumb.

    In general replacing an 85C capacitor with a 105C capacitor is cool. It's especially cool if the replacement is low-ESR -- it will probably run marginally cooler :D There are possibly some places where the designer has relied on ESR for some reason, so it's not universal. I would be careful replacing large filter capacitors in some cases due to the possibility of increasing power-on transient current.

    Rated tolerance for capacitors is huge. I wouldn't worry about it a lot in this application. It's highly unlikely to be critical.

    Remember that the 200V capacitor can bite (in some cases quite badly). See if you can make out if it has some sort of bleed resistor. If not (and even if so), measure the voltage on it before you work on the board to see if it's hiding a special surprise for you or your equipment.
     
  18. Tesla

    Tesla

    165
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    May 10, 2010
    Ok, for the (8) low voltage 16volters, I need: 47uf, 220uf, 470uf, 1000uf.

    How do these look? (see attached PDF)

    The Nichicon HE series appear to be your basic general purpose Japanese e-caps.
     

    Attached Files:

    Last edited: May 16, 2010
  19. Resqueline

    Resqueline

    2,848
    1
    Jul 31, 2009
    For the four big bad cap's I'd highly recommend Nichicon HZ's (stocked by Mouser) which have an extremely low esr and high ripple current rating. The others seems to be not so stressed so it's not so important what you replace those with. I'd consider replacing the small one on the HV side, but wouldn't bother with the big one.
    Here is a link to the HE series, and here is a link to the HZ series.
    As you can see the HZ's are around 3 times as good as the HE's. Go for low-ESR first and high ripple second, and use as large can as you can (increasing height too).
    I'd not have any reservations about fitting a 1800uf in place of a 1000uf. Increasing voltage is theoretically safest but unfortunately 16V is the upper limit of the HZ series.
    As you can see the HZ's are rated at only 2000 hours life as opposed to the 7k-10k hours life of the HE's, but the HZ's endure it at 3 times the ripple current so they should live much longer than the HE's in actual use in that PSU.
     
  20. Tesla

    Tesla

    165
    2
    May 10, 2010
    Just so you know, I have already ordered the Nichicon e-caps (eager to get on with repair), but I'm am interested in understanding what you are trying to explain to me.

    I ordered mostly 16v HE because the specs looked good and the Datasheet had bullets like Low Impedance, High Reliability and Long Life. Some (due to selection) ended up being PW series which is like HE but adds the marketing bullet "High Reliability for SMPS".

    http://products.nichicon.co.jp/en/pdf/XJA043/e-pw.pdf

    These seemed closest to what was in there already. I'm sure these quality Japanese caps will work better than the cheap generic Chinese ones.

    So, on the HE and HZ datasheets, the spec are you looking at that says the HZ is "3 times as good" is Rated Ripple, right? So, you think Rated Ripple is more important than [email protected] ? ... or just another thing to concider when determining durability?

    I did look into upgrading to 20v e-caps. However, it seemed that I had to move up to Polymer caps like the LV series. They are marketed as "Low ESR" and "High Ripple" ... both things that you guys are telling me are important.

    While I have seen these polymer-caps on PC Motherboards (and other sophisticated motherboards) I can't recall ever seeing them in a SMPS. Is this just because of cost (they would be over-built) or some other reason? Are the polymer caps a direct replacement for standard e-caps (if basic specs match)?

    http://nichicon-us.com/english/products/pdf/e-lv.pdf

    I've always know there are different caps for different applications (obviously) but I'm not sure I ever appreciated the granularity.
     
    Last edited: May 16, 2010
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