Some info about the LNBH26 U4 from the TUNER Si21662 DUAL REV B2 (MOD2016/4). Mainly some ohm measurements and pin connections from/to the LNBH26. Click picture for a full view. This is the 3th drawing and shows the tuner measurement from a old damaged, and new tuner. Also added the LNB input values A/B as also the note to the lnb ic.
Hi Wish u will be fine and enjoying good health . I need to share something I have the same tuner 2166 in dm 900 . since few days I am experiencing it drops the signal after 15 to 25 mints. I have cross checked with an other dm 900 . The tuner is working awesome in it . no issue at all. I have cross checked with another tuners Fbc 45308 and with combo tuner 2169 . Box behaves with the same time frame after working fine 15/25 mints it again drops the signal and show tuner failed . these tuners are checked with single straight cable without any diseqc switch . I have also checked the V/H during this malfunction . volts are stable at both sides 2nd I have replaced the power supply with 12v/5amp to 12v/3.5 amp almost 4 power supply unites checked with this box . Images checked during the test Experimental original image Merlin Image Open Atv 7.3 Open Atv 6.4 Currently runing Merlin in flash and Openatv in Barry Allen . ( installed it for further tests if have any doubt over images). Same setup is working flawlessly at Octagon 8008 Duo4k Dm900. Waiting for your valuebale reply . Thanks in advance for ur always kind help and support my friend .
From what I read, it comes to my mind that it maybe might be a CPU and/or NAND flash chip problem. When I think of the nand chip, I think of reading/writing the nand chip, but if it is related to warming up the box, then I think of the CPU, but a Nand chip can also have read/write problems if it gets too hot. What I would do (at least as a test) is cool the pcb with a fan and see if it continues to work without any problems.
Good Morning . Yes Its 110% true its about the cpu issue . I have tried it last night to cool the cpu , put a fan ( dm800se) over heat sink. Yes it works some better but doesnt fix the issue. after more than a hour it started to drop signal and with in few seconds the result was 'Tuner failed' and also slow downed the performance . I am afraid the final solution would be reball the pcb . A blind target .
Yes, that is quite possible because the solder balls can dry out due to age and can shrink during heating.
https://jb8a8f8.com/support/index.php?threads/dm900uhd-voltages-measurements.292/ Studying this thoroughly . I will share it with you . If I see something strange against the theory.
Of course it could be anything, from a defect on the PCB/tuner, to the dish head and/or cable. But if it is caused by the PCB, then I usually think of the CPU. In any case, these types of problems are often difficult or possibly impossible to solve because they can also be caused by bad print traces and/or soldering.
Do u think a partial heat through heat gun to some suspicious areas over motherboard can fix the issue ? Is it a worth to try ?
Normally I use Freeze Spray to diagnose faulty electronics, bad PCB traces or bad soldering when it is in the error state. Normally it will work again for a short time, and then I usually know in which area to look. But the other way around is also an option, theoretically it should work.
