Sure, I get the intention behind that. I’m using myself a TL-ST1008F on my desk which also has its ports in the back. But it’s only SFP and has 10G.
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Ouch, the instructions to flash OpenWRT on these switches are … scary!
For a Netgear GS108Tv3, are the LEDs still an issue that require a custom /etc/rc.local to enable or have the latest images fixed it?
AFAIK either you still need rtk network on or the rc.local sequence.
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This is exactly why companies exist, that have these products. You can buy the transcievers and get them programmed for your devices and if you have a decent amount, you also get the programmer.
At least in the European market they are the go to vendor for trancievers.
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Yes, FS, FlexOptix, etc. exist and offer those services. Only some of those sell to individual consumers though, and they are generally still overpriced, sometimes significantly so.
FWIW, I found FS Germany to consistently offer the best prices on the simple mode bidi optics I need for my fiber uplink and the same goes for the fiber patch cable to go with it (in the case of the latter, almost an order of magnitude cheaper than local online stores, even)...
I’ve got a TP-Link TL-SG2008 now if any experienced kind soul wants to turn it into an officially supported device, I’m willing to help test. Not afraid to take the cover off and short pins 
The only difference between the TL-SG2008 and TL-SG2008P appears to be the absence of the TPS23861 used to provide PoE. Have you tried loading the TL-SG2008P OpenWrt firmware? If this works then a pull request creating a new DTS that is a copy of the sg2008p dts with the addition of disabling tps23861_28 node would suffice. It appears from the original pull request for the sg2210p that this was the initial intent. Quoting from the pull request:
This device shares the same board with the SG2008P and SG2008. To
model this, declare all the capabilities in the sg2xxx dtsi, and
disable unpopulated on the lower end models.
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I will try it, hopefully it boots even though the TPS23861 is missing. Where are the instructions on how to do it? I’ve seen them before but can’t find them.
note the link and
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Ah, soldering required too …
The instructions say ROM (U7) but the wiki says U6. I guess I’ll find out which is correct when I open mine.
This is very confusing. Do you need resistors or just solder bridge for both?
Usually resistors in series in UART lines are there (at least in part) for protection purposes, they will limit the max current into or out of the chip which is "behind" them. You can probably just use a solder bridge, but if you have some ewaste (and a multimeter) available, then it might be better to salvage a few resistors and use those instead - usually values up to 150 ohms will work fine with common SoC UARTs (I've seen values up to 1k used in the past, but that might limit max baud rate). I've no idea about this SoC, but try it and see.
Usually I use isolated UARTs (or isolator boards) to add some safety to myself, my laptop, and the device under test (especially when mains voltages and/or questionable power supplies are in play) e.g. this self-contained unit: https://www.aliexpress.com/item/1005010005236496.html or this add-on module: https://www.aliexpress.com/item/1005006681015099.html (that particular aliexpress seller "WeAct Studio" makes good quality stuff - to the extent that other aliexpress sellers rip off their designs!).
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On switches such as the TPLink Omada SG2008, there are L3 features in the stock firmware, inter-VLAN routing. Does that traffic go through the weak CPU or is it done all in hardware? What happens when they are flashed to OpenWrt, can OpenWrt do the same acceleration or is the inter-VLAN routing handled by the CPU then?
the RTL838x hardware in the TL-SG2008 has some support, the implementation in OpenWRT is started, but is far from working => expect to see routing on CPU for now
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I opened up my TP-Link Omada SG2008 v4.26 (UN/4.26, UN=universal market, not US, EU, etc.). The firmware calls it “SG2008 4.20“, it currently runs stock 4.20.13 Build 20250928 Rel.82909
I have some questions:
- Confirm that is Pin 16 CLK – I believe it is correct based on the Winbond W25Q256JV chip documentation.
- I assume the unpopulated J11 is the UART. Pins and soldering required. I don’t know the pin order, Tx, Rx, …
Edit: Starting from left most pin (the one with the arrow underneath): pins 1/2 are Rx/Tx though not sure which just yet, I assume the R112 nearby needs to be closed first, Pin 3 is GND and Pin 4 is +3.3V (measured with a voltmeter). - I cannot find R27 and R28, my eyes are not what they used to be … where about on the PCB should I be looking for them? Or do I have some newer v4 revision that is different from previous one? The R112 nearby the UART seems like a candidate for a solder bridge because no way I can solder a very tiny resistor there.
I suspect either the pull request for the SG2210P is incorrect about the relationship between the SG2008P and the SG2008 or their are different versions using different board layouts. The SG2008P image at TP-LINK TL-SG2008P V1.6 board top is very different from the image you posted above.
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TL-SG2008P has a v1 and v3. The hardware must be very different and different from my SG2008 v4.2x
I have some confidence that I identified the UART in mine, though not exactly sure what I can do from here. Perhaps best to just run stock firmware for now, given that I don’t even have pins to solder on the board.
If you're not 100% confident with soldering and identifying a UART etc. then you might want to get some low value / scrap device (e.g. a very old wifi access point or set top box or similar) and use that as a testbed to practise on. If you don't have a logic analyser, then this one is "cheap as chips" as we say in Britain - https://www.aliexpress.com/item/1005003649856071.html (I know I'm looking like a WeAct Studio shill at this point, but I just think they make good value stuff) and will also help with i²c and SPI debugging (as long as the signals are under 12MHz or so). If you think you might need to capture faster signals, then there are some RP2040 and RP2350 (raspberry pi pico / pico 2) based logic analysers which go up to and above 200MHz for about €/$ 30.
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