DM520HD Network strange behaviour

Discussion in 'Hardware troubles and Repair support.' started by uncinogb, Feb 20, 2021.

  1. uncinogb

    uncinogb New Member

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    Hi everybody. I wonder if you could help me with a very strange problem with my DM520HD original.
    From one day to the next the lan started to misbehave. A network test showed link ok, but no ip. It also became impossible to connect to the box from the rest of the network. At first I thought that something had gone wrong with the software and tried to reinstall my orignal openpli 5. I ended up having to do that through the mini usb and here is the odd thing. Once I set an address through putty I was then able to use the web rescue interface to reflash the box. Cleraly at this point the network hardware must have been working, but once the box booted up in the fresh firmware the network was not working again. I disabled dhcp and set an ip address manually but the problem remained. I still could not make a proper link to the rest of the network. Please note that there is nothing wrong with my network as installing an old box on the same connection was just fine.
    Could this be a very strange hardware problem that only appears when the box is connected to a network but not when it is connected to a single computer with fixed ip addresses?
    I am totally confused and any clue would be much appreciated.
     
  2. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Yeah this is a very strange behavior, and I can only think of a a mac address issue.
    I think, check the mac address in your dhcp router.
    Release the leased mac address in the router from the box could I think help.
     
  3. Kartenali

    Kartenali New Member

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    In some Images they haved a Failure for the DNS Adress i haved this Issue on my 820 HD too
    what happen if u use an Other Image is the Failure still there ???
     
  4. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    DNS Address conflicts are often related to another device on the network which uses the same ip address.
    The router dhcp server may give a same ip to a device which is already had it, especially when there is also a same mac address conflict, then the dhcp server thinks that is it the same device, thus gives it the same ip.

    Nevertheless, some image files, especially backup image files may change the mac address of the box, sometimes that is good, or just not.
    I'm not claiming that this is also in your case, it's just a thought of what it might be.

    Now, I do not know how complicate your network system is, it may have sub nets, vpn etc.
    As also the computer of which you attempt to connect to the receiver may have blocked it, maybe due a security program, or other cause.

    Anyways, all of it are just some blabla of what it might be, and may have nothing to do with your issue.

    As for,...
    Once I set an address through putty I was then able to use the web rescue interface to reflash the box.

    That's correct, by this way you force the receiver to use a setting that you had self made.
    Basically, you gave the box an dhcp ip trough a tool, and not due the router.
    This may tell that the box, the network side is fine, network cable probably also, but it's a issue with your router, the dhcp releasing side.
    Maybe it helps when you restart your router which is responsible for giving the dhcp ip's.
    Maybe it helps if you flash the box with the latest software as openpli 8.0

    In any case, I have not the idea that it might be a hardware issue of the box, but still, network issues can be tricky to solve.
     
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  5. uncinogb

    uncinogb New Member

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    Thanks very much for all your replies. I have done some more testing and almost concluded it is not a network problem. The mac address of the box is unique on the network and the rare times the box connects to the network (see below) the correct address appears on the router. I have rebooted the router and also used a secondary router on the network. Same problem. I have changed the cables with no benefit.
    On the box I have tried the following:
    Changed images including the bog standard original image on the dreambox site
    Updated the rescue loader with the latest from the dreambox site
    Run various tests in CFE mode and in normal rescue mode.
    In rescue mode I found that testing with ifconfig and plugging in and out the network cable I got a link sometimes. It was during one of these rare times that I managed to update the resce loader directly from the dreambox site
    I also tried to resolder the terminals of the DGYKD socket, but got no better results.
    I could post a Putty log of the box booting up and the box going into resue mode if that could halp. I noticed in a full boot log the following lines:
    [ 0.512000] Bad block table found at page 262080, version 0x01
    [ 0.513000] Bad block table found at page 262016, version 0x01
    [ 0.514000] nand_read_bbt: bad block at 0x00000ace0000
    [ 0.515000] nand_read_bbt: bad block at 0x000011920000
    Could this be a clue? Could this cause a random LAN misbehaviour?
    Thanks you guys, I very much appreciate your input.
     
  6. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Hmm assuming it is a hardware issue, then there is not much to do because all network communication tracks are directly connected to the cpu.
    Therefore it could be a bad connected solder ball under the cpu.

    Another thing wat it might be, and thinking of a hardware issue is thinking of a damaged coil wire internal in the network connector.
    Which may be measurable by using a uH meter.

    Some info about it..
    DGKYD KRJ-003NL single port shield 8P8C with internal transformer 10/100 BASE-TX RJ45 female Jack.

    krj-003nl-datasheet.jpg

    Maybe, when you replace this connector for a new one it fix it, but there is no guarantee that it will.
     
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  7. uncinogb

    uncinogb New Member

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    Thanks Johnny. Do you think that the bad block table founf at.... is significant and could infact point to a CPU problem that could cause this LAN peculiarity? If you think it could be then I will not bother to attempt to change the DGKYD but if you think it is unlikely then I will try to source it and replace it. Many thanks
    p.s. Everything else seems to work just fine on the box
     
  8. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    That depends, normally are bad blocks that are found be ignored by a new software installation and therefore you may expect no nand flash chip errors in the log file.
    But if there is corrupt data on these bad blocks, and related to the network, than yes, it may the reason.

    Nevertheless, that it precise is related to the network data seems to me nearly impossible.
    But when I have this issue, and can't solve it, than I would use a usb wifi stick.
     
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  9. uncinogb

    uncinogb New Member

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    Thanks, what you say seems very sensible. I have a wifi usb stick that I tried, but it has an RTL8188SU chipset and cannot find a suitable driver for the DM520HD. Can you suggest another inexpensive wifi dongle that would work on this box? By the way I am currently using OpenPli 5. I did try the Japhar OpenPli 7.2 but it did not want to install and gave up on it.
     
  10. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Yes, maybe are the drivers for it not present in the image file but based on what I see on the ourdreambox, then it may maybe installed with telnet.
    But that's not a option when the network failed.

    But tomorrow I'll be able to check which wifi usb stick I use.
    And/or maybe will Toysoft react to your question.
     
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  11. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    I've tested the ralink rt5370 usb wifi receiver and works with it, that is.. it's tested with openpli 8.0
     
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  12. uncinogb

    uncinogb New Member

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    Thanks Johnny. I have now sourced the KRJ-003NL from China for $11 including shipping. I'll let you know when I get it if that was the problem. In th meantime I will try an rt5370 based wifi dongle and see if it works with OpenPLI. Presumably any dongle based on the rt5370 chipset should work with the same drivers, right?
     
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  13. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Yes indeed, the rt5370 chip set is supported with as I know all images for the dream/vu boxes etc.
     
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  14. uncinogb

    uncinogb New Member

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    Update. I have now found that the RT5370 wifi usb dongle does not seem to be supported on a DM520 box running OpenPli 5 but it works just fine on a DM500 running the same OpenPLI. I will do more testing with different firmware as soon as I have more time.
    On the LAN saga I have now found that the box LAN connection works fine if I connect it to a router with a crossed cable!! When I use an ordinary straight through cable, as I should for a connection to a router, it does not work. That makes me think that the problem is definetly with the RJ45 connector. I will update when I get a replacement one from China and will update.
     
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  15. uncinogb

    uncinogb New Member

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    Latest update of the LAN saga.
    First please be advised that the RT5370 wifi usb dongle works perfectly in my DM520HD running OpenPLI 8 but not OpenPLI 5 which seems to lack the necessary driver.
    Regarding the LAN problem I have now replaced the original RJ45 KRJ-003NL connector with a brand new KRJ-003ANL. These connectors are electrically identical and the only difference between the 003NL and the 003ANL is the external casing where the 003NL has some finger tags on the outside whilst the 003ANL doesn't. The problem has not gone away. No difference in beheaviour. The LAN works perfectly with a cross over cable to the router but not with a straight through cable. Yes I have tried different cables and different routers and confirmed the problem is with the DM520HD. Note that this problem occurred all of a sudden out of the blue and I can only assume it is due to some other internal hardware failure of the box.
    In conclusion: The fault was not due to the RJ45 connector nor the firmware nor the external cabling or the LAN setup in general. Everything works fine except that I must use a cross over cable to connect the box to the router. I am reporting my latest findings in the hope that my experience might be useful to other members and would like to thank all who have replied or just followed my saga, lots of thanks in particular to Johnny B.
     
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