06-01-2019, 04:02 AM
(06-01-2019, 03:17 AM)Nikolay_Po Wrote: Okay, no problem. It is hard to a customer to do a developer's work.
The shorter wires are needed to eliminate the cross-talk between digital lines. Usual plastic-cased jumpers are too large and have very high capacitance (edit: for such a high frequency signals as 6Gbps SATA protocol). So being placed in vicinity on signal pairs, the jumpers are distorting the signals. One signal, say, transmission form SATA adapter to HDD will induce a crosstalk with next jumper in a row, to the receive signal. And vice versa. There may be both distortion - a cross-talk between receive and transmission and the distortion of signal form (eye-diagram closing) due to the reflections from heterogeneity introduced by the jumpers.
These jumpers are most suspicious part.
Do not touch the SBC by a solder yet. Probably the jumper replacement helps.
BTW, you may ask to replace the jumpers the specialist of nearest phone repair shop. Usually they have good enough soldering skill.
Thank you for the above post Nikolay.
Regarding soldering wire, I cannot find solid wire thin enough to fit, can I use braided copper wire or use existing posts from one side, bend it in u shape and use that?
I will try soldering myself and if not successful I will order better card as soldering charges in here will cost double than ordering a better card.