DM8000 blue light only when power on

Discussion in 'Hardware troubles and Repair support.' started by mwd123, Aug 12, 2017.

  1. mwd123

    mwd123 New Member

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    Hello!

    I have tried to search abit for the error of my DM8000 but I cannot find any solution.

    The DM8000 was unpowered during flash (power outtage) and after that it is no longer operational.

    When I power on the DM8000 all I get is the blue light shining on the front, if I press the standby button at front the blue light turns off, if I press again it turns on.

    The serial port does not respond either to DreamUP or serialconnections from putty (tested other boxes and the communication is fine from the PC)

    I have tried to replace the serial port, from a working DM8000 but still the same.

    I have tried a working PSU from a working DM8000, still same thing.

    I have measured all the connectors from and to the PSU and they are good comparing with the schematics on this site.

    I have measured all the 12V spots on the motherboard, from schematics on this site, they are all fine.

    I have removed extra tuners, WLAN-card, display, etc.. still nothing.

    Any hints on what to do next? would love to get this box working again :)

    Best regards
    mwd123
     
    Last edited: Aug 12, 2017
  2. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    This is a difficult error which is not so easy to say what it could be.
    It could be due the front panel.
    Or the nand flash chip is death, or flashed with a wrong image file.

    But still, sorry to say but I can not give a good advice for the blue led issue while it's not due the psu, or other most common way.
    Maybe someone is reading this and may give you some better ideas of what it could be.

    Or.... maybe this trick works, by heating up the psu it may work as you can read here,
    https://jb8a8f8.com/support/index.php?threads/dm8000-original-out.125/
    Nevertheless since you already have tried it with another power supply from a working box with the same result it may not help but it could be that your defective motherboard ask a bit more amps consumption on a circuit than your working box.
    Therefore a working psu may fail, while it's warmed up it may work which is mostly related due outdated caps on the psu.
    In any case, blue led is mostly related due the power supply.
     
    Last edited: Aug 13, 2017
  3. allllex

    allllex New Member

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    mwd123, did you solve your problem? I have a similar situation:
    (I apologize for bad english, translated google)

    Question to Johnny B.
    DM8000 at night in Standby mode the clock stopped at about one in the morning and showed the wrong time in the morning.
    The box did not react to the remote.
    To restart the box was turned off and turned on again by the switch on the box.
    After that the box was lit and the blue button is constantly on and boxing is no longer started ..
    The display does not work at all.
    The hard drive, CD - drive, WiFi card, fan were removed.
    The TV and the LAN cable were disconnected
    There were no additional tuners in the box.
    According to the recommendation:
    http://www.ourdreambox.com/ubbthreads.php?ubb=showflat&Number=1598#Post1598
    all the voltages on the motherboard were measured.
    All of them are exactly the same as the recommended voltages:
    https://jb8a8f8.com/support/index.php?attachments/dm8000-power-supply-dcvoltage-jpg.301/
    The voltage at the 3-contact 6,74 volts (6,74 or 2,5)
    Stresses were measured on the recommendation:
    http://www.ourdreambox.com/ubbthrea...ber=951&filename=Dm8000hd-pcb-12v-circuit.jpg
    All voltages OK
    The power supply was replaced with a new one like this:
    http://www.ourdreambox.com/ubbthreads.php?ubb=download&Number=2321&filename=DM8000HD-5L0565-PSU.jpg
    No changes.
    An attempt was made to connect with the box through the serial RS232 Hyperterminal. Hyperterminal does not see the download log.
    An attempt was made to record the software via Ferrari Filler. The program can not contact the box.
    On the recommendation from here:
    https://jb8a8f8.com/support/index.php?threads/dm8000-original-out.125/
    The motherboard and the box were heated with a hairdryer. The results did not give any.
    Front panel working on your recommendation
    (And if you do press the front button, measure also the 14v while pressing, see if it collapse to a lower voltage.
    If so, then you may have a faulty front display.
    This you can test, by disconnecting the front display from the front panel,
    or is some cases the box turns on without connecting the front panel.)
    Everything says about your conclusion:
    "Or the nand flash chip is death, or flashed with a wrong image file."

    Is there any jtag in this box?
    Is there a dump for this nand?
    Where on the motherboard nand flash is located.
    Why do I need this dump here?
    http://www.ourdreambox.com/ubbthreads.php?ubb=showflat&Number=1937#Post1937
     
  4. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Last questions,
    Q1, Is there any..
    Yeah there is an jtag option but useless because there is no fix software for it.

    Q2, Is there a dump..
    Not needed, you can just replace the nand chip, and write to it on the regular way.

    Q3, Where on the..
    The nand flash chip is under the wifi card located.

    Q4, Why do I need this..
    It's a backup from the Eeprom and you only need it if you have a issue with it, however you need a Eeprom programmer for uploading it to the Eeprom.
    In any case, a corrupted or defective bios rom results into the blu leds, no display etc. issue.
    If it's mounted in a socket then it could help if you remove and clean it.

    I think, maybe you need to replace the rs232 chip, maybe it helps to get access to the box.
    In any case, with a defective rs232 chip it's not posable to do any attempt to try to fix the box but when the box is stuck on the blue led you cant get a terminal output, so it may not help to replace it.
     
  5. allllex

    allllex New Member

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    You speak:
    "when the box is stuck on the blue led you cant get a terminal output, so it can not help to replace it".
    So the replacement of the chip at the moment is not relevant.
    At the first stage it is necessary that the bokks start to load, anyway, as correctly, or incorrectly.
    To display some information on the display.
    As I understand it, it is covered by bios, and not nand flash.
    So I need to try and rewrite Bios.
    After all, you say:
    "In any case, a corrupted or defective bios rom results into the blu leds, no display etc. issue.
    If it's mounted in a socket then it could help if you remove and clean it".
    As I understand, on the motherboard it is necessary to search for a microchip with the name 39VF040, because for it on the above mentioned link there is a BIOS file DM_8000_EEProm_39VF040_512k
    I think that this BIOS chip is in a removable slot near the SIM card.
    But I have this chip called M27W401.
    Bios is not completely dead.
    The motherboard provides 3.3 volts to turn on the power supply.
    The cooling fan is constantly rotating.
    Or am I wrong? Also it is necessary to be engaged in a flashing nand flash XC9536XL.
    How to understand your words "and write to it on the regular way"
     
  6. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Fan, If it's connected to the (hdd) 12v power connector then it's logic that it runs, but if it's connected to the four pins fan connector, and the fan has 3 or 4 wires, then it's strange that it runs because this motherboard fan connector is controlled by software and the cpu.

    Bios rom, All (older) types dreamboxes has the M27W401 bios rom and can not be reprogrammed, they are OTP (One Time Programmed).
    Therefor you can use the 39VF040 which can be reprogrammed, and is reconized in most of the nand flash programmers.
    It is also tested, and working on the dm8000hd and other dreamboxes, so this Eeprom can be used as a replacement.
    And yes, If there is a issue with the bios rom, then the box will be death, only the blue leds will be given.
    However, from all the dm8000hd cases I have repaired, I had only twice that it was related to the bios rom while it was soldered on the motherboard, and so it's rare.
    But when it's mounted in a socket, then it has more chance that this may be the case, often is in that case cleaning the pins, and socket the solution..

    Regular way writings, I mean working with a wxp system and using dreamup, and the box connected with the network, and serial cable.
    However, the serial port from the box could be damaged, these rs232 chips are often defective and so when that happens then you can not do the flash process with dreamup, it simply refuse to make a connection to the box or does connect but failed to upload to the box (read or transmit issue Rx/Tx).
    Therefor I always replace the serial module, or replace the rs232 serial chip if I don't have a spare serial port module to see if it's helps, just to be sure.

    Nevertheless, only blue leds, and a death box is in most cases related to the power supply.
    Also, even a spare psu, one which you now that it worked before and has not used for a long time may become defective and may give this issue.
    So I noticed yesterday, from the six repaired power supply's I have there were two that gave this error while they all were repaired and tested a time ago.
    And so, be convinced that the power supply you use are really working well, because otherwise you try to fix it on the motherboard while it's actually accourse due the psu.
    Check the caps on the psu, especially the C109 because if this small cap refuses, then you ends up with this issue.
    It's a sensitive circuit.
    Or, if you can, test the psu on another box, to be sure that it works well before you think it's a motherboard issue.
     
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  7. allllex

    allllex New Member

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    Yes, fan it's connected to the four pins fan connector, and the fan has 3 wires. When the box is turned on, the fan starts spinning at the speed it used to spin in Standby.
    The internal Usb connector is also powered, and USB starts to glow, but does not blink.
    LAN not blink

    "Only, only blue leds, and a death box are in most cases related to the power supply."

    Well, I will check the power supplies.
    I'll start with the 25x4 block

    1. measured the resistance of the unit without connecting to the motherboard according to this instruction:
    https://jb8a8f8.com/support/index.php?threads/power-supply-connector-ohms-measurements.54/
    Great differences:
    on the 3rd contact (6.4 V) should be 58.5 KOM, in fact 8.06 KOM.
    on the 10th contact 3.3 V) should be 33.79 kom, in fact, 3.01 kom.

    Measured voltage in the box on the motherboard:
    (1) 14 V - 14.87 volts
    (3) 6.4 volts - 6.8 volts
    (4) 3.3 V - 3.31 volts
    (5-6) 12 V - 12.2 volts
    (8) 5 V - 5.14 volts.
    (10) 3.3 volts - 3.42 volts
    (12-13) 2.5 V - 2.52 Volts
    All voltages are close to those recommended.

    Your comment?
    Probably I need to measure the voltage on the power supply without a motherboard on your recommendation?
    https://jb8a8f8.com/support/index.php?threads/dm8000hd-25x10-psu-voltages-measurements.122/
    3.3 volts I'm going to take from the receiver, which is another power supply 5L0565. The box also does not work with it, but the motherboard returns 3.3 volts to this block for 4 contacts and it turns on.
    I will take 3.3 volts and ground.
     
  8. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Indeed, Ohm measurements on the psu could give some indication of the state of the psu.
    As for the pin 3, this could be the cap C605 and p10 the cap C703.
    In any case pin 3 is related to the U2 and 10th to the U1 but I have no reason to think that it is due the ic's.

    On this picture you can see where it goes to,
    dm8000hd-psu-p3-10-Snap.jpg

    As for the voltages measurements, be aware that even if the voltage are all there it does not have to mean that the psu does not have any issue.
    Normally should it also be measured with a oscilloscope to see if these voltage have also the correct waveform output.
    Because it's not only the voltage which plays a role, the voltage frequency must also be correct.
    But, because not everyone has a scope device, or have some nowlidge to use it I only use the Ohms and voltage measurements.
    Nevertheless, with Ohm measurements it could also be a good indication if a voltage circuit is fine, or not.

    As for the fan etc,
    Yeah a bit strange but maybe I can test this tomorow on a motherboard, it looks as if it's still in standby mode, but normally if the motherboard has been turned off it should/must be going out of the standby mode.
     
  9. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Just to be (I think) sure if the box is into standby mode or not..
    This can be seen by measuring the display connector on the display.
    According to my measurements is one 3.30v delivery switched off when it's in standby mode.
    As you can see on this picture.. dreambox-8000hd-frontpanel-info.
    In any case, a interesting measurements place to check but be careful with measuring, best is to use a needle probe.
     
  10. allllex

    allllex New Member

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    I measured the voltage on the power supply not connected to the motherboard, but with a 3.3 volt connection per 4 pins.
    Here are the results:
    IC600 - OK
    IC830 - OK
    IC200 - OK
    L601 (6.8) - 4-5.6 no stable
    JCD2 (10.3) - 10.14, no stable
    IC700 - OK
    R302 (3.3) - 6.6-7.6, no stable
    IC830 (10.2) - 6.6-7.6, no stable
    (GND) - 0
    (2.4) -2.49
    IC400 - OK
    D700 (x) - 2.87
    (x) = 0
    D500 - OK
    Q400 - OK
    D300 - OK
    IC500 - OK
    L300 - OK
    Q200 - OK

    Hot section
    Q100 (13) - -102
    (x) - -102
    (x) - -102
    LC101 (13.2) - -102
    (5.5) - 0
    (1) - - 108
    About the condenser C109, the lacquer was melted.

    I measured the voltage at the output connector of the ribbon cable at the output of it from the front panel to the box.
    At least 4 of the 7 contacts available for measurement have a voltage of 3.3 volts

    Yes, the box is in the standby mode.
    All the voltages fully correspond to the picture for Standby. There are two voltages of 3.3 volts.
     
    Last edited: Oct 15, 2017
  11. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Pin 3=, C605/Coil L601/U2 unstable..
    Pin 10=, C703/Coil L701/U1
    Just see if the replacement of the caps helps.

    Measurement display, standby..
    Interesting, if it's indeed giving the measurements as if it's in standby mode then it's strange that it does not go out of the standby mode when the motherboard has switched off.

    Maybe, but this is very rare when it happens, maybe there is somewhere a cap on the motherboard which not fully unload.
    I do not known which chip is used for the standby mode, but I do know that it only needs a few voltage to stay in the mode.
    Maybe a lazy cap, or something, thinking of this method...
    Disconnect the motherboard from the psu, and unload with a 12v lamp all the caps near the psu connector on the motherboard.

    If that does not help, then I'm thinking of a sort of continuous command which set the box into standby, but have no clue were to look.
    But I guess, most logic seems to me the front panel, maybe it helps if you hold some front push buttons, and then switching on the box.
     
  12. allllex

    allllex New Member

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    "Just see if replacement caps help."
    No, do not help

    "Disconnect the motherboard from psu and unload the 12v lamp on the motherboard."
    No, do not help

    "But, I think most of the logic seems to me on the front, maybe it helps if you hold the front buttons, and then turn on the box."
    No, do not help

    My box died in the standby mode. At night, the clock stopped at 1 am.
    The box did not respond to the remote console. The switch was turned off and turned on at the rear, and then only the blue indicator of the "Start" button.

    Now once again carefully measured the voltage on the front panel.
    0 v | 0 v
    2.8 v | 3.34 in
    3.3 v | 0 v
    3.3 v | 0 v
    3.3 v | 0 v
    0 v | 14.9 v
    3.33 v | 0 v
    3.35 v | 3.34 in
    This is the standby mode, one voltage drops to 3.175 V to 2.8 V.

    Now I measured all the voltages and resistances on another 5L0565-PSU power supply, which I bought as a spare, along with the purchase of the box.
    Resistance does not differ much from yours.
    Due to the supply voltage in the box box there are no differences from yours. The difference can not exceed + 0.2 volts.
    In accordance with the voltage of the power supply unit, separate from the box, the coincidence with all voltage points from here:
    https://jb8a8f8.com/support/index.php?attachments/ic400-ic500-5l0565-in-output-jpg.490/
    The only difference between the IC400 chip and the bottom contact is 9.1 volts, and I have 0.97 volts.
    Check, please. The supply voltage is only 9 volts, and from the microcircuit 9.1 volts. (More power).
    I bought it, tried to install it, but on the motherboard there is a slightly different output connector. So I did not install it.
    Because the original power supply was working in the box.
    Now I installed it. And it does not work either.
    I doubt that two power sources do not start the box.
    Therefore, I doubt that the power unit is to blame
     
  13. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Yeah well, as for the 0.97 volts, that is correct.
    As for the fan running, two blue leds on etc.
    If I remove the bios rom, then..

    When the box is turned on, the fan starts spinning at the speed it used to spin in Standby.
    The internal Usb connector is also powered, and USB starts to glow, but does not blink.

    Only is the LAN leds not on.

    And so, It looks as if the bios rom does not work, but it is not totally the same.
    When I take a psu which give the blue leds (I tested two of them) then the fan is not spinning etc.

    So, it seems to be a motherboard issue in your case, but at this moment I have not really a clue what it could be.
     
  14. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Maybe if you measure the bios pins it may tell something.
    However the data connections are not so easy to measure.
    dm8000hd-biosrom-vdc.jpg
     
  15. allllex

    allllex New Member

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    I removed the M27W401 chip from the BIOS socket, and turned on the box without chip.
    Nothing changed.
    "When the box is turned on, the fan starts spinning at the speed.
    The internal Usb connector is also powered, and USB starts to glow, but does not blink.

    Only is the LAN leds not on. "

    So the BIOS does not work? I deleted it.

    Now I will put the chip in place and measure the voltage.

    A16 - 3,35v
    Vpp - 3,36v
    Vcc - 3,37v
    A17 - 3,35v

    G - 3,35v
    E - 3,36v

    A0 - 3,35
    A4 - 3,35v
    A5 - 3,35v
     
    Last edited: Oct 16, 2017
  16. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Red voltages are stable, as for the others, they are switching between the 2.7/3.3 due the data.
    If all these data voltages are stable on 3.3v then it could be that there is no communication between the bios rom and the cpu.
    So I have also tested what happens if I use a bios rom from a dm800se.
    The data lines from/to it were confused because it did not understand this data on the chip, the voltages were going up and down.
    Useless to say that it did not work on the 8000hd.

    In any case, what your measurements result could mean is that the cpu does not make a attempt to make a connection to the bios rom, or the bios rom corrupt the communication between them.
    So, it's difficult to say if it's due the bios rom, or the cpu.
    If I must do a guess, then it could be the cpu, however with doubts.
     
  17. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    But thinking further about it, check these pins without the bios rom.
    Suppose that the data voltages are unstable, then it could have a good chance that it's the rom itself which caused it.
    However, I can only check it on my board not earlier than on Wednesday.
     
  18. allllex

    allllex New Member

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    I measured the voltage across all the contacts of the bios when the chip is removed from the box, and when the chip is inserted into the socket of the box.
    There is no difference.
    On all the contacts of the chip there is a stable voltage of 3.35 volts.
    The exception is the contact Vss. There is always no tension on this contact. (0 volts)

    I also have a bios from the DM800SE (China).
    I can insert it into the box and check the voltage.
    I understand that the bios is different and it will not work.
    Just to see the tension.
     
  19. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Yeah well, as I said earlier, tomorrow I could do some more tests.
    And further thinking on it, it could also be a crystal, but for that I need to remove some to see what happens.
     
  20. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

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    Sorry, I had/have to much repairs to do, therefore I had not had time to check several things on the 8000hd, this upcoming weekend I have more time for it.