Problems with MikroTik S+RJ10?

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ewer0012

Member
Feb 10, 2019
81
25
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I was just using 2 of the S+RJ10 to go from my living space to the basement where my rack is for 10Gbe with a 125ft Cat6A cable. They worked great till I started transferring data over that cable, then they got ridiculously hot and started having transmit/receive failures. When I say "they got ridiculously hot" I mean they got ridiculously hot. I was going to see if there was anything physically wrong with them so I pulled one out, it burned my fingers and palm (little bit of blistering, nothing serious). I was a little smarter with the second one and used an infrared thermometer and it read 81C (Mind you it took me a good 3-4 minutes to get my thermometer and get to the basement to check the temp).

Has anyone else experienced anything like this with RJ45 to SFP+ transceivers? I've read that they run hot, but didn't think that it would be this hot. I'm wondering if I got a couple of defective units, or if they really just run that hot. Everything I've seen online says they run up to about 50C, which is a long ways off from 81C. FYI, it's about 19C in the basement.

I was running them between two MikroTik switches:
CSS326-24G-2S+RM
CRS309-1G-8S+IN
 

Waterkippie

Member
Oct 12, 2017
58
15
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The cable you are using is too long for 10G, the limit is 30M or 98 ft. See the mikrotik brochure for info on maximum lengths.

MikroTik

So either lower the speed to 1G/2.5G/5G and check again? Or just switch to fiber for this distance :)
 
Last edited:

ewer0012

Member
Feb 10, 2019
81
25
18
I ended up switching to Fiber.

I tried these S+RJ10 units with a 3ft Cat6a cable between switches and they were still getting up to 75C at the lowest and 79C at the highest. Maybe I just got some defective units? They've since been returned.
 

Rand__

Well-Known Member
Mar 6, 2014
6,626
1,767
113
Its on the side were the serial number is. But no problem just wondered
 

kroy

New Member
May 17, 2019
24
7
3
You aren’t supposed to run them next to each other. You need a gap in between them.
 

kjboughton

Member
Dec 7, 2017
30
12
8
45
These run hot AF.

I purchased a couple for testing last week.

Linked right up at 10Gb but then a test transfer showed closer to 2.5Gb consistent over a 10ft CAT6A copper run.

Max temps were upwards of 85C before I pulled them.

Additional fan with directed airflow did not help the situation.
There is not enough surface area to cool the modules using external cooling alone.

These are beta junk. I will be returning mine.

Not happy with the review done on this page.
Yes, they are hot. They are FLAMING HOT.

EDIT: These are guaranteed to be rev 2.16 and can be sourced domestically:
MikroTik 6-Speed RJ-45 Module
 

Patrick

Administrator
Staff member
Dec 21, 2010
12,511
5,792
113
All of these modules run super hot.

Just curious which switch are you using with them?
 

kroy

New Member
May 17, 2019
24
7
3
Ubiquity USW-Pro-24-POE Gen2
Were you placing them next to one another? That’s a huge no-no

I have a bunch of these and I have no problems getting full 10Gb. My biggest complaint is that my revision 1 don’t support jumbo frames.

The Unifi might not have enough cooling in the right place to run these. They definitely aren’t beta junk, but it’s one of those things that might not work out for everyone.