ASUS GX1105B Gigabit 5 port Switch (Year 2009) Packets Loss and Repair

[Kiriakos GR]

Asus Switch GigaX GX1105B - Repair

While I had originally purchase my ASUS GX1105B (Gigabit 5 port Switch) at August 2009, this was not a random decision.
At the year 2009, GX1105B was fresh-born technology, first supporting Gigabit 5 port Switch in compliance of all known networking protocols.
Along fastest hardware, and sum of features pack this offered at a sweet price.

This period of time, my ASUS GX1105B this completed a life cycle of 13 years.
At my LAN I did notice that GX1105B Led indicators they were blinking at extreme fast rate even when there is no activity due the network.
External ASUS 12V 1A PSU, I do inspect this internally every few years, and this was good.

Then I did run my faithful networking diagnostic software and I did discover packet loss, in the direct connection of my switch-hub with my VDSL router IP.
Originally I thought that my patch-cord cable might when bad, but no, I did test three cables and the problem was still there.     

I did decide to take apart my GX1105B, and in my surprise four essential electrolytic capacitors all when bad.
From original capacity of 470uF they had decrease down to 30uF.

By replacing all the damaged capacitor with new, quality of service along behavior of my gigabit switch-hub this is now restored, to good as new. 
In the past eight months I was detecting small packet loss at my connection with the internet but I could never suspect that my gigabit switch-hub this was suffering from DC voltage regulation issues.

NIPPON CHEMI-CON: KZG series capacitors are designed for computer motherboards
Endurance with ripple current : 2,000 hours at 105C

Up to date with 24/24 operation they survived for 116,328 hours   
ASUS I do not have a complain from you, but the way that I did discover this damage, due of packet loss benchmark, this is not documented . 
 
         

[Andrew-88]

Since the moment that switch-hub technology this succeed to deliver an entire product this based to single-chip for all it functions, only DC power issues will stop it from working properly.

So, internal capacitors turned in to dust, but even so the external PSU this was not able to compensate for a proper operation.
There is only one explanation,  12V Input this is then converted at several voltage rails internally, possibly an 5V and even 3.3V or other.
And these low voltage rails collapsed.

Very few have electrical and IT skills combined, so to review these clues and navigate at the source, so to solve such a puzzle.

 
 

[overvolt]

Very few have electrical and IT skills combined, so to review these clues and navigate at the source, so to solve such a puzzle.

This is true, most people would start first a battle with their internet provider about VDSL Packet Loss issues, when the devil this was hidden within this switch-hub.

Kiriakos troubleshooting method worth's gold, smart owners they might rescue their appliances, and this will lead at two benefits.
a) electronics waste reduction.
b) Cash saving's if they have skills and tools so to perform this repair.

GX1105B (Gigabit 5 port Switch) performance specifications along features they are very good!
 

[Andrew-88]

GX1105B (Gigabit 5 port Switch) performance specifications along features they are very good!

At such gadgets in-depth specifications, they are out of my range of understanding.
But I am well aware, that Kiriakos he does always wise shopping decisions. 

[Kiriakos GR]

So, internal capacitors turned in to dust, but even so the external PSU this was not able to compensate for a proper operation.
There is only one explanation,  12V Input this is then converted at several voltage rails internally, possibly an 5V and even 3.3V or other.
And these low voltage rails collapsed.

Very few have electrical and IT skills combined, so to review these clues and navigate at the source, so to solve such a puzzle.

I was under pressure so to get this thing up and running the soonest possible, and I did not make any electrical measurements, so to confirm actual voltages of these three voltage rails.

This is double-sided PCB, the bottom side this is 95% covered with copper.
Removal of half-dead capacitors and cleaning of their PCB pads - holes (from old solder), this required three hours of careful work, along wise handling of Hot-Air tool along of soldering iron this working at 450C.
The circuit it does appears simple in the eye, but the required workload for safe capacitors extraction and replacement, this is significant.

They are spacing restrictions, capacitors height must be very specific.
In a later time, I might research so to order an modern series of NIPPON CHEMI-CON as replacement.
For now, I did use 105C  470uF of capacitors random brand which I had in stock.

This battle ended successfully for now. 

[Kiriakos GR]

Year 2022  NIPPON CHEMI-CON KZN series 9,000 hours at 10~50V replacement of old KZG series 2,000 hours.
 
https://www.chemi-con.co.jp/en/products/detail-condenser.php?part_number=EKZN160ELL471MHB5D

I did find stock in Germany.