TrendNet Ethernet Switch: Jian Capacitors?

[TheLaw]

So I bought this $12 TrendNet 10/100 switch because like many of us, I have quite a few Ethernet devices around the house.

Just for kicks, I decided to open it today, because that's what I do.

To my dismay, I found some caps branded as "Jian". What the hell is that? Looked online, and found 0 documentation. (Perhaps one of you guys have heard of Jian?)

The nature of these devices is that they tend to fail because they overheat or are driven to hard...so I'd like to keep that from happening to soon. I'd like to replace them, but finding no documentation on them, I'm not sure exactly what to use. I'll be ordering off Mouser/Digikey somewhere in the next week for an unrelated project, so Nichicon, Chemi-con, and Panasonic are all viable. HN? FM? FC? KZE?

2x 470uF 16v- 8mm
3x 47uF 16v- 5mm


Thanks.


To the manufacturer of crappy electronics: If you are going to use bad quality components, atleast use bad quality components that are easily identified.

[TheLaw]

Re: TrendNet Ethernet Switch: Jian Capacitors?

I have another question. For the power supply brick, it has 2x 400V caps. This will never see 400V because I live in the US, so, can I use 200-250V caps instead, and then up the capacitance?

The inside of the power brick is attached. 120V comes in on the left. Before it hits those caps, it runs through a SMD diode bridge on the bottom of the board, so the rectified voltage is like 170V-180VDC, with an absolute max voltage of around 200V, I'd say. So I was considering uping the 6.8uF 400V and the 4.7uF 400V to something higher capacitance, but with a lower voltage, perhaps 200 or 250V.

Is that feasible/good idea?

[ipman]

Re: TrendNet Ethernet Switch: Jian Capacitors?

Which ones are the 400V caps? No two of them are the same. How they are connected? Series (does not make any sense)? Parallel (only seems logic if it's rated for 220-230-240V operation)?

[TheLaw]

Re: TrendNet Ethernet Switch: Jian Capacitors?

Which ones are the 400V caps? No two of them are the same. How they are connected? Series (does not make any sense)? Parallel (only seems logic if it's rated for 220-230-240V operation)?

They are in parallel. One is 6.8uF and the other is 4.7uF. I think they did this because the 4.7uF was the biggest they could fit.

[ipman]

Re: TrendNet Ethernet Switch: Jian Capacitors?

Then you should be fine with lower voltage rated ones. Maybe you can fit a larger value one and forget about the other, because the board looks very crowded to my taste.

[PCBONEZ]

Re: TrendNet Ethernet Switch: Jian Capacitors?

Interestingly a Jian is a double-edged straight sword used during the last 2500 years in China.

The company is Jian Long Electronic (Bao An) Co., Ltd. [China]
Same company also makes YEC [branded caps].
If you have a series name look it up under YEC.

Now I'm going to try and quit laughing and come back later.
.
.
See top title line....

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[ipman]

Re: TrendNet Ethernet Switch: Jian Capacitors?

Don't worry, you will see that ofthen. It's called "chinglish", as I was told when I was there.
And that's a minor mistake

[TheLaw]

Re: TrendNet Ethernet Switch: Jian Capacitors?

haha. okay. Maybe I can fit one on it's side that is like 22uF or something.

That won't be bad for it, would it?

[PCBONEZ]

Re: TrendNet Ethernet Switch: Jian Capacitors?

The black ones don't look in parallel, there is a coil between them.
Also looks to be something between the green ones. Can't make it out.
Maybe you should draw that one out.

On the main board if you don't have a series name I would direct measure the ESR and guestimate what series they cross with.
Lacking that I would choose in this order depending on what physically fits and where you buy....
FR
FM
HV
HD or KZE
HE or KY
.

Don't you see....
2000 year old Chinese sword makes YEC.
.

[TheLaw]

Re: TrendNet Ethernet Switch: Jian Capacitors?

The black ones don't look in parallel, there is a coil between them.
Also looks to be something between the green ones. Can't make it out.
Maybe you should draw that one out.

On the main board if you don't have a series name I would direct measure the ESR and guestimate what series they cross with.
Lacking that I would choose in this order depending on what physically fits and where you buy....
FR
FM
HV
HD or KZE
HE or KY
.

Don't you see....
2000 year old Chinese sword makes YEC.
.

If only I had an ESR meter...

I'd say FM would probably work. It's not too low, not too high. If it dies...well, it's not the worst loss.

[PCBONEZ]

Re: TrendNet Ethernet Switch: Jian Capacitors?

FR and FM have almost identical ESR & Ripple specs and sizes but FR has a longer Endurance which implies they might last longer with heat.

[lti]

Re: TrendNet Ethernet Switch: Jian Capacitors?

I don't see what is so funny.

[PCBONEZ]

Re: TrendNet Ethernet Switch: Jian Capacitors?

Noted