Discussion in 'Hardware troubles and Repair support.' started by jason666, May 27, 2016.
When i startup the box from the 5 leds, the middle one is off (D202).
What does that mean?
Connect the usb sevice port to a computer and use a rs232 terminal program as Putty or other to see if you receive some data.
Terminal settings are,
Bits per second = 115200
Data bits = 8
Parity = None
Stop bits = 1
Flow control = Xon / Xoff
If you get no received data, than you may have a hardware failure.
Maybe a dropped voltage, to check/measure this see the Faultfinder measurements.
Other things you could try..
Remove the sim card, see if it gives another leds status.
Check your 12v power supply, if it is not a original for these box it may have a to low amp delivery.
It must be at least a 3 amp 12v power supply, better is some higher as 5 amp.
An 2 amp is to low for these receivers.
i've checked the voltage and pin 5 is not ok. i measure 2,6 V instead of 5 V.
any clue what could be broken?
A while ago I made good diagrams of the voltage circuits,
As also for this circuit, see this 5v diagram drawing..
The source is the LT1940/U1104 Sw1 output, see the arrows where it goes to.
As example, to know if the U1104 works, remove the 0 ohm resistor R1125, and see if you get the 5v from the LT1940.
If so, then it's after the R1125, remove inductors (L parts) / 0 ohm resistors to find the source.
However, I had some cases that the fault accursed from the usb module, the defective chip on it drops the 5v source.
Remove, unplug the usb module to see if the 5v issue solves.
it`s me Klaus . First of all I have seen Your pictures regard my VU+duo (mini) clone. I at least understand now
what You tried to tell in Your email.
But coming to my Prob I do have with the DM500 motherboard Itould You before. The middle LED of the five
is of. The measurement on the P1100 all ok and present.
Any idea what else I can do? It is a SIM2.10 installed. The bootlog on the HTerminal shows:
G=00000000 R=00000000 W=00000000 00000040
IMHO, K6 error is one of the worst problem( at least for me). I would say it can be from various reasons.From 2.5V path to CPU , through DRAM path to CPU itself.
I tried to find a solution to K6 error but not found yet. But let's wait for Johnny.
Hi Klaus and Jane..
Yes indeed, the K6 error is a tricky and often unsolvable fault.
And has as far as I see it to do with the memory chips.
1. It could be the ddr regulator, but happens rarely.
2. Bad memory chip, sometimes but it's difficult to say which one.
3. Main voltage for the memory, sometimes but mostly not.
4. Cpu interruption to one of the memory chips, more often and sometimes to solve with pre-heating, and if not it's most likely a bad print track.
Bad print track can sometimes be found if you press a little between the cpu and the two memory chips on the parts side.
In some cases the box just starts, however also this could be a bad cpu solder connection.
5. Cpu bad, mostly not but sometimes it is and only to solve with a new cpu (if you could get the correct programmed cpu for this type of receiver which will be hard or impossible to find).
The leds only shows the first boot cycle, till it has passes the security chip.
A long time ago I've tried to make a diagnostic overview from it, but it's not easy to say what it all means.
I think if it passes step 4, then it has passing the security chip, but this is not entirely certain.
Thank you for K6 explanation.
But do you believe that CPU is really programmed for different boards ?
I understand that CPU is programmed by registers programming but it is( done during BOOT phase) from BIOS values. But you imply that CPU is programmed from the factory already.
Do you have any proof for that?
Proof, not really, only from my own experiences as recently had using a dm800se sunray cpu on a old type ferrari dm800se board.
It failed, with the vmlinux error which is than a driver issue.
Later I had removed it, and placed on another sunray board which had a cpu issue, on this board it worked.
And later I had get from someone a old dm800se board with a hdmi failure.
Removed the cpu and placed on the previous old motherboard with the vmlinux error and just works.
Also, you may think that a sunray board with the mini flash up button has into the bios the data, not in my experiences.
When I had used a cpu from a older board without this option, the sunray board is just working on it, but it loses the mini flash up option.
So, with this knowledge, it was for me clear that the cpu's are programmed for the type motherboard, thinking of the hardware registers which you can see with the Bbs/I2c.
But okay, these where used dreambox cpu's.
So I have allot of new cpu's from different sellers and failed.
Some gives the K6 error, others the vmlinux error, and when I use a used dreambox cpu it goes mostly good.
Further, these type cpu's are used in many different devices which has other hardware, for example the (old) Clarke-Tech ET9000 with a BCM7405 cpu, I doubt it will work on a dreambox because the memory chips and nand flash chip are different.
In any case, I didn't found any seller who sells the cpu's which are suitable for the dreambox.
A few years ago I did, one seller on ebay, but even with these I had some problems, 4 out of 10 failed and later it getting worsen.
And all the BCM7405 cpu's I had bought from aliexpress failed, all of them, not one worked.
Maybe just bad luck, but since then I have stopped buying new cpu's due the loss of money.
But nowadays it is not really useful to buy new cpu's for the dreambox, at least for the sunray or other clone motherboards due the sell price of a new box.
Only if it's a original dreambox it may be useful, but I prefer to use a old cpu from a donor board which has a hdmi or K6 error.
But see the pdf's about this BCM7405 cpu for more about it.
Thank you for your info.
Yes, it is possible that CPU need not work properly on one mainboard while can work on the other.
But I would think it is because of a mainboard problem not because of CPU difference.
When I myself played a little bit with BBS last year I found out that it is BIOS that changes register values.
I think also it is easier for Broadcom to implement BIOS programming feature then CPU programming( it could be rather tedious for a satelite receiver manufacturer to program each pc of CPU according to his mainboard design). And I do not think that Broadcom would program CPU according to a customer demand( if the quantity is not large enough, of course).
I bought recently two pcs of BCM7405 - one used with DM500HD original- worked well, the other used with Estar - did not work - K6 error. But I would say it is ESTAR problem, not CPU problem.
Some time ago I also recovered K6 error with reflowing. I tried reflowing with another board ( also K6) but I failed.
Do you mean that HDMI error can be on one board while not on the other?
Thank you for your feedback.
hdmi question, yes.
But this has nothing to do with the motherboard, that is.. if it's not a print track issue or other cause as a defective d600/d601/d602 diode.
But it's mostly a bad connection to the cpu.
Nevertheless, if I have a old motherboard with a hdmi problem, I use mostly the cpu for a younger board.
preferably a original box which is more worth to repair.
To go further with the bcm7405 cpu story..
Programming.. to be, or not to be...
Well, I think that it's not unlikely that a satellite receiver manufacturer prepared some chip as the cpu, security chip and bios rom to suits their receivers.
Bios, changes register values...
I'm not sure if the bios has the needed data to changes the bcm register values, but may plausible.
If so, then it must be a one time process because otherwise it should not be a issue to use a used cpu on a other board which is not always the case.
Johnny, you mentioned HDMI. How do you check,( if there is a problem with HDMI) that it is CPU problem?
As to BIOS and changing registers, when I tested, I removed BIOS and checked some registers. The values were not correct for the mainboard. Then I inserted BIOS and the values became correct. And whenever I changed the values of registers, after restart ( if BIOS used) they were correct again. So, I guess CPU's registers are changed on a fly from BIOS
Hdmi cpu check..
By removing the cpu, cleaning it, and to check the solder points or they are still shiny.
Often you see in the hdmi area dull contacts on the cpu.
Sometimes it can be solved with a thin needle to scratch the contacts clean.
But sometimes there is a contact point disappeared, then it really game over to the cpu.
But if everything is still shiny after removing the old solder, then the chance is that the cpu is working well.
Interesting, to investigate it.
I will try to talk about it with Linlin, that is.. if he is still reachable for this kind of questions.
Maybe later more about this...
Johnny,If I understood properly, NO HDMI error can be also caused by a poor CPU connection and reballing should help( in some cases). Can you please let me know the reballing success rate? (So far I have thought that CPU is faulty and the only way how to repair HDMI error was replacing CPU).
Thanks for the reply.
Yes indeed, the success rate is generally high.
Only a few are due to the CPU itself from my experience.
Let's say, one of the 10.
Especially with boxes that have stopped spontaneously with hdmi, without a reason.
That is very good success rate regarding HDMI. Congratulations.
And do you have a similar success with network problem(when network does not work)?( I change CPU only ).
I mostly replace them with a network problem because the chance that the cpu is working after re-balling is not so high.
The network is a different story than the HDMI.
HDMI has an power-surge protection on the data lines, and on both sides.
Thus, a television device has it, but also the satellite receiver, and sometimes when you have a hdmi switch it gives a third protection.
And so, the risk that the cpu has been damaged is not so high.
Network is only separated by coils which are sometimes placed on the motherboard, or internally in the network connector.
After it, it goes almost directly to the broadcom cpu, so problems on a network will most likely damage the cpu.
So, unfortunately, it is often fatal for the cpu when there was some trouble with the network as a lightning strike on it.
But of course you can check the cpu with ohms measurements.
By simply comparing the network connections as the Rx/Tx dots ohm values with a good CPU.
If they are in the same range, than it is a good chance that the cpu may work well.
And I think that it is quite possible that you can also check a CPU with an HDMI problem to see if the CPU is good or not, by comparing the data hdmi dots values with a good one.
In any case, an hdmi, or network problem, may be measurable on the cpu dots.
Nice to see discussions about this problem.
My 500HD (original) has something similar. It works well while its cold (i can flash it, even boot up), when it heats up (about 10+ minutes), it freezes and after a new start it all ends in the console with "K6 F"
Whats interesting- my dm500hd cooling fan does not start to spin, i swaped it with another PWM 4pin fan, same thing. How does your fan act?
Not sure what should i look for in my case. I contacted my local satellite shops, they do not want even to reball the cpu.
Thank you for your discussion.
Hi, as for the fan, and if it's a hardware issue you can use the schematic I had made from the dm800se, most of the parts are the same part number an both box circuits are build similar.
Click on the picture for a full view...
In any case, the fan speed is controlled by the cpu, but if the Q1200 has some issues, or the 12v feed to it then the fan will also not work, same as the 3.3v before the resistor to the rpm speed.
However, it could also be due the software, maybe it works if you install the fan controller2 plugin.
In any case, if you have installed it, you are be able to do some fan testings with it.
That the box gives issues when the fan isn't working could happen, because it needs the fan to operate otherwise the cpu will become to hot, therefore some solder balls under it may become disconnected from the motherboard.
But also the motherboard itself may get bent under the cpu due the heat, if that happens then a new or re-balling the cpu will mostly not help.
Yeah well I'm also has stopped with this service because these original boxes are offered on ebay for around the 90 euro's because there are now newer boxes namely the dm520hd/dm525hd and also the dm525hd combo with reasonable prices.
Therefore is the cpu repair for the dm500hd no longer worth to do.
But also, be sure that you psu is working fine, the box needs at least the 12vDc and 3 amps to work flawless.