Tragic Tales of Capacitor Failure

Digix DV-288 DVD Player Power Supply Repair

This simple repair wouldn't deserve mention, except that it addresses a very common failure mode for modern consumer electronics and computer equipment. Undoubtedly a lot of money is wasted, and otherwise perfectly fine equipment sent to the landfill, for want of a similar fix.

The subject is a Digix Media DV-288 DVD player, serial number DV288125112926, version 3.1, manufactured in December 2002. It was originally purchased from Fry's Electronics for $35. (This model is easily unlocked for region-free operation. On the remote, hit SETUP 1 3 6 9 8 8 8 8. A VERSION entry is added to the main setup menu. From the VERSION menu, select region code 00.)

After a few years of trouble-free operation the player began to exhibit erratic behaviour on startup, randomly freezing or displaying corrupted video. The oval power indicator on the front panel, lit by blinding blue LEDs, would dim whenever the player attempted mechanical activity or illuminated any of its status lights. From this evidence it was deduced that the power supply was no longer providing sufficient voltage, and a repair was undertaken.

The layout inside the case is very sparse: just the drive, which contains all logic and video electronics, and an Achme Corporation AM229B switch-mode power supply, rated for +5V@2.0A/+12V@0.2A. (Achme Corporation, get it? Apparently they once had a web presence at http://www.achme.com.tw/ which is no longer available.) Cursory inspection of the power supply immediately revealed the problem: two 1000uF capacitors with bulging tops, one of which was already crowned with an orange crust of leaking electrolyte.

The offending caps are intended to work in concert with the coil between them to develop +5VDC for the drive. The actual voltage measured closer to 4V, dipping even lower when more current was needed. The caps were Fuhjyyu brand, rated at 1000uF 10V 105C. Based on copious discussion at badcaps.net it appears that Fuhjyyu is hardly the seal of quality.

The caps were desoldered and replaced with KME (Nippon Chemi-Con?) 1000uF 16V 105C units salvaged from a new (non-functioning) Dell UPS. The replacement caps were substantially larger than the old ones, with a wider lead spacing; fortunately, the power supply board had two sets of pads to accomodate a variety of caps and they fit perfectly.

The player worked fine after the repair and once again provides trouble-free service.

Linksys WRT54G Power Supply Repair

An apparently non-functional Linksys WRT54G wireless router was deposited on our doorstep one day, complete with original Linksys model M1-10S05 power supply. The router functioned as designed with an alternate 5V 2A supply, and so the original was dissected by prying apart the two halves of its case with a screwdriver.

A bulging capacitor on the corner of the board was immediately evident. Upon removal it was identified as a Teapo brand 330uF 25V part. Teapo does not appear to have a web presence beyond considerable public notoriety on various forums, identifying Teapo capacitors as a common point of failure even without visible indication.

A replacement capacitor of suitable value and form factor could not be found, so repair was effected with salvaged Taicon Corporation 220uF and 100uF 25V capacitors wired in parallel. Taicon, a proud member of the Nichicon corporate family, seems to have a reasonably good reputation as summed up by this remarkable testimony on badcaps.net:

"i looked through a 5 gallon pickle bucket of dead caps as i poured them into the dumpster today. no tiacons in there i could see." --willawake, Badcaps forum member

After the repair the supply worked perfectly and the router currently enjoys renewed service life.

Contact: reboots at g-cipher.net
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