DC blocking caps + ? in sata data lines?

[slap_happy]

I have a vintage (2010) Zinwell ZIN-5005HD media player to which I'd like to add sata port(s). The player is based on the Realtek RTD1073DD which supports up to two sata ports, and the Zinwell board is configured and silkscreened for these two ports, but they are not installed. See attachment photo.

I've installed sata ports in other Realtek-based media players before, but in those cases all that was required was 4 dc blocking caps and the sata jack. The Zinwell board has locations for the 4 dc blocking caps (C204, C206, C208 & C210), but it also has silkscreening for either resistors or inductors(?) in series with the 4 dc blocking caps and the sata data lines. See R185, R187, R189, and R190 - or L23 and L25.

The same single board location is silkscreened for both the resistors and the inductors, so I assume either one or the other is installed. If the entire board is examined (see here), the other board locations that are labeled this way (dual-labeling) sometimes have resistors installed but other locations have inductors installed. I'm assuming the "Lxx" locations are inductors. I could be wrong.

So, I tried to find some schematics of sata data lines with dc blocking caps AND also resistors or inductors in series with the sata data lines.

Does anyone have any idea what function resistors/inductors might have when installed in series with the dc blocking caps in sata data lines? At this point I'm thinking of just jumping those locations and installing just the caps, since I don't know what should be installed at the resistor/inductor locations.

That, and every other realtek media player I have (more than a dozen) has only been configured for the dc blocking caps.

[redwire]

Re: DC blocking caps + ? in sata data lines?

Capacitors C204,206,208,210 are for EMC filtering. The caps go from SATA data+/- to GND. The same caps set is used on the USB port, but they were left out. They are not needed, in a pinch.

Common-mode inductors L25, L23 are for EMC filtering. You'd have to jumper the two sets of in/out pads to bypass them and complete the circuit.
I can't see the resistors anywhere. They are probably an alternative to the CM inductors- Just plop resistors on, to bypass the inductors.

D21 is optional for ESD protection;

[slap_happy]

Re: DC blocking caps + ? in sata data lines?

I just checked C204,206,208,210 with a microscope. They are in series with the sata data lines. They don't have one side going to ground like C213, 214, 217, 218 do on the two usb port data lines. I will try to take a picture with a macro lens. My plan is to install the usual value dc blocking cap in those locations.

Thanks for the information about L23,25. Looking at the linked photo of the entire board, the HDMI jack has resistors installed in the locations L16,17,18, 19.

So, I guess for the HDMI jack they "plopped resistors on, to bypass the inductors". And maybe I should use the same value resistors in L23,25 to bypass the inductors for the sata jack? Or a jumper/blob of solder might do just as well?

[redwire]

Re: DC blocking caps + ? in sata data lines?

They look like 0R jumpers; you can check with an ohmeter. If so, a blob works wonders

Oh, it is DC blocking caps, not EMC. It looked like GND pour in your pic was one end of them, but must not be the case.

[slap_happy]

Re: DC blocking caps + ? in sata data lines?

I installed the caps in the Lxx locations, because the pads are bigger there. Then I jumped the Cxxx locations instead of installing inductors. Finally, I installed the e-sata jack. It is a little messy, but it works. See attached photo.

The lack of EMC filtering and ESD protection are the sort of things that keep me up at night, but I've never seen those circuits included in other like realtek media players.

This media player has been sitting "new" in a sealed box since 2009-2010. There are some Jackcon 1000uf caps (see other attached photo). How does Jackcon rate in the world of electrolytic caps? I probably should change them.

[Th3_uN1Qu3]

Re: DC blocking caps + ? in sata data lines?

Replace them, they are crap. They are a step down from Jamicon and that is saying enough.