Johnny, do you have any experience with Dreambox 7020HD receiver? That DM7020 has K6 fault. BCM74130011 012 K1 K2 K3 K4 K5 Shmoo Version=3.8 DDR Freq=0x0000018C %00000001% G=00000000 R=00000000 W=00000000 00000040 # K6 F I replaced CPU but no change. As you say, in one of posts in this forum, it has something in common with memory. Can you please check the following questions and let me know your oppinion? 1. when Dreambox( any model) starts, it reads BIOS first, but does it read the whole BIOS at one go or just some bytes? 2. From your experience is it worth trying to repair that K6 fault? 3.You have very nice schematics of Dreambox. When do you make that reverse engineering to make schematic, do you remove all components from the mainboard first? Of what is your procedure? Thanks again for your help.
Hi Jane.. Yes the K6 F error happens if one of the memory chips fails due a bad chip, or print tracks to it, or bad outdated solder. Suppose it is a bad mem chip, then it can be solved by replacing all the memory chips from another board. Only replacing one memory chip often failed. Nevertheless not really a easy job to preform and will not always succeed. And yes, the bios, as the settings are read first, when removed you see that all the motherboard leds are weak on. As for the schematics, most of them were build from a clean motherboard to get a reliable print track overview.
Johnny, Thanks for your reply. Speaking of replacing memory chips( 4 pcs DDR), do you have any trick how to know that a particular mem chip is good( if using from used mainboard)? Those mem chips are BGA, do you have any link where a stencil for reballing can be bought?Or do you use soldering balls instead of soldering paste &stencils? Thank you for your reply.
I'm not sure if it is also for the dm7020, because I had used it for the dm800se/500hd But I used the, no: 310 ddr2-3 0.45mm stencil And used solder balls instead of paste but it was not easy to do. And no, I have no tricks to measure which chip may be defect, I replace them all, or in some cases first one, see if it chances, if not replace the second etc. However the chips are normally a set of four, adding another later produced chip may not work.
Johnny, Thank you for your reply. I exchanged CPUs(BCM7413) From working mainboard I took the CPU and replaced tha on DM7020HD( It had K6 fault that was the reason to be repaired). But now DM7020HD has still K6 faults and that previously working mainboard has also K6 fault. Do you think it would be DDR problem or rather PCB problem of M7020HD or even it had both CPU faulty and something else besides?What is your oppinion?
There are several scenario's to think of as depending on how it's done.. A: > Good cpu swap to K6 board, result still K6 error. A:< K6 cpu swap to good board., result still K6 error. A1> K6 board has some issues with a print track to a memory chip or something else as different memory chips as the board it came from. Cpu has no drivers for the type memory chips it has. A1< Good board with K6 issue, memory chips different than the board it takes from, or just bad luck with replacing the cpu, or cpu has some issue related to the memory chips, or while placing the cpu you have not protect the memory chips with kapton tape for heating up, result solder balls under it melted, which gives the error. But this is one of the things it may have, there are more things to think of why the good board failed. So have I a working vu duo board which have a to low memory, it can upload a image file, and will booting up, until it notice the low memory. Spend days on it, but still not found the reason.
Johnny,you are correct and my fault again. DM7020HD should have 512 MByte RAM, while DM800SE( I used the working CPU ) should have only 256 MByte RAM. Do you think those CPU BCM7413 will be preprogrammed so it is not possible to just replace them? Thanks for the reply
Yes, I myself am convinced that the hardware data such as memory chips and nand flash chip data has been programmed into the CPU. So a used cpu keeps the previous hardware data. With a new cpu, maybe it become one time loaded with a new cpu. Maybe the CPU can be reset via I2C, but I do not know, but do not consider it impossible. I myself have been through bad experiences with new cpu's. Often they end up with the k6 error. Regards bcm7413, I have a long time ago used a vu uno cpu on a dm500hd, and it still works fine. Maybe lucky, or other reason.
Johnny,Thanks for the reply. Can you please explain what you me by 'With a new cpu, maybe it become one time loaded with a new cpu.' a little more?Loaded from where? I would say it would be easier programming via BIOS. In the past when I played with Broadband studio, BIOS really changed value of NAND flash( in CPU registers, for instance.but when I reset Dreambox the values were not stored. You say that you successfully replaced CPU from vu uno cpu on a dm500hd.Do they have the same configuration then?
My is told.. A new cpu does not have any drivers in it, only the broadcom regular programmed data. When it placed, it's still open for receiving the needed drivers for the hardware environment. How it should get the data, I don't know but assume it's going true the I2c bus. Or it get it from a bios rom, or maybe just from the software while booting. Question cpu from a uno to a dm500hd bcm7413, yes and I still have this box working while the specs are different. No clue why... BCM7405, RAM 256, Flash 64 BCM4713, RAM 512, Flash 128 I've made a picture from it,
Johnny, Thank you fro your reply I understand but then it would be very difficult to replace /exchange those CPU. And also even to replace with a 'new' bought CPU because you do not know if it was not used previously( you also know that from China not really new ICs are really new ). What is your success rate of replacing those BCM7413/7405 ?
Yeah, in the beginning, a few years ago I bought the bcm7405 new on ebay from digikey which were mostly good. Let say from the ten, one failure. But later he had other product dates which all failed. So I have more than 40 new cpu's and all with different issues, because of this I had stopped buying new cpu's and only use used ones. But good tools are also important to have. My first Bga station was the Achi ir6500 rework station which works fine, but it was not reliable. Sometimes it just become crazy and burned the motherboard, or pop corned the new cpu. Later I modified it with better heating plates etc, but still never worked reliable. In any case when everything goes good, it just succeed the job with good results. Later I bought the T862++ IRDA to see how it goes with a Ir lamp, but I didn't like it. To long process, and not suitable for the cpu's. I used it now mainly for memory chips or other smaller parts. And so, I had a wish, one bga work station which is reliable and automatic. Because removing a cpu is not so hard to preform, but placing it precisely on the board was always a difficult task to do. So my next station is now the total automatic BGA rework station LY890A which have also a optical alignment system. With this machine it is a easy job to remove/placing a cpu and also fun to work with. Since I have it is the failure less, that is if the cpu is reliable. In any case it is with this machine not due the bga process that it failed. But still, this is not a cheap bga rework station to buy, and the regular bga stations are basically good enough for replacing a cpu.
Johnny,thanks for the reply. I started with IRDA machine( do not remember the number already) but it was not good for me either.Later I bought ACHI and it works well. I also had issues with popcorned chips but it was because of bad profile.After correcting the profile it works really well. Soldering /desoldering of CPU is not difficult for me either but cleaning tin after removing ( desoldering ) CPU - also bad smell from old flux- it is not a nice job for me.Do you use any fume extractor? I also ,from time to time, use CPU from a working mainboard to be sure that the CPU is good. But from my last experience DM7020HD issue, even this is not problem free :-( . Today I have also tested BIOS versions. I replaced Ferrari SE bios in original DM500HD and there was no K6 error. But I would guess ( not tested yet) that if I place Ferrari BIOS into DM800SE V2, I will get K6 fault, because V2 has a different memory size from 800SE. What is your oppinion? ( You know it is still very hard for me to believe that CPU are prepogrammed for a particular main board and as that it can not be used with a different board without a way of resetting).
For removing the cpu/motherboard from old solder I use AMTECH NC-559-ASM Flux Grease. Most of it with the solering iron, and the rest with solder wick. To remove the flux I do it with a ultrasonic bath with Ultrasonic PCB Cleaning & Flux Removing Fluid. And yes, of course I aware of the profiles for the bga stations, but my Achi station have sometimes a bad spooky moment. I've replaced/upgraded everything, top bottom heater all with Elstein, timers, probes etc replaced, even the usb to rs232 module with a newer chip to fit for w7 and higher. But still, sometimes it just do his own thing instead of following the profile. Spontaneous it rises very fast all the heating plates to it's max, never found the reason why it happens. But okay, I have now a good station which works reliable. And yeah, I have no proof that the cpu has the hardware information in it. And it's basically not logic because you may expect that it's done trough the software, or at least if the receiver has it, a bios rom. But still, I think it has to do with the identification of the memory and nand flash chip or something but it's still not clear. Forgot to say, If a take a cpu from a mobo with samsung chip, and I place it on a board with elpida memory chips. It results also into the K6 error from my experiences. Same may happens if the nand flash chips are different, then you may get boot up issues.
Hi Johnny, I also use Amtech 559 but do not use ultrasonic bath because I do not have a such large one.Only use IPA and clean it with hand. Regarding a replacement CPU from a used mainboard, do you mean that even DDR manufacturer must be the same so that Iam able to replace CPU successfully? Do you have any successful rules that must be followed( from your experience) for such CPU replacement? Thank you for the reply
I do not really have a good method to determine whether a cpu is suitable for reuse. Often it remains a gamble. But a CPU that provides HDMI problems, or problems with connections to the nand flash chip provide a good chance. But mostly also look at the solder balls under the CPU with an HDMI microscope, as they are dull I try to reuse it. Also if the cpu is still green colored, not overheated. I also figured out a way to test a cpu without soldering. The cpu must be equipped with solder balls. On the motherboard, after cleaning the old solder I use the cpu stencil and solder paste. I put a thin layer of solder paste on the board dots, and place the cpu on it. As weight, I put on top of the cpu a block of lead. Then I heat up the motherboard to 100 degrees, not higher because otherwise the solder paste will react. This is a one-off process, and good only for short test to see if the motherboard will start. I check that with the terminal. If it works, then I remove the CPU, make everything clean and mount the cpu in the normal way I remove the cpu hot air, because sometimes the cpu heat the solder paste ans so sticking to the cpu/motherboard dots. It is a working, and good method. However, placing the cpu in one time is difficult, shifting is not an option. And if the solder paste had become to warm, the solder on the cpu may be useless to reuse. In that case the cpu needs to be re balled.
Hi Johnny, Thank you for sharing of your good ,clever, test method. I am testing it when I have a possibility. Can you let me know what kind of stencil you use? I use an universal one which is acceptable for reballing but not the best for your test method.
I also use the universal stencils, but have used wide kapton tape on it, and only opened the holes which are used. The only thing is cleaning it afterwards, but for this I use the ultrasonic bath whereby the tape still stays for more reuse. The drill must be sharp, and done by hand, but it is to do.
Hi everyone...i am a new user here. As per my knowledge the K6 F error happens if one of the memory chips fails due a bad chip, or print tracks to it, or bad outdated solder.Suppose it is a bad mem chip, then it can be solved by replacing all the memory chips from another board.Only replacing one memory chip often failed. turnkey assembly services
