[The design of the R1000Ã¢â‚¬â„¢s plastic case which totally lacks any ventilation for the PSU that remains permanently powered Ã¢â‚¬ËœonÃ¢â‚¬â„¢, and thus runs at very excessive temperature, is a major contributing cause of these failures.
However, it is now a proven fact that by their selected use of very cheap underrated capacitors which are totally unsuited for the task (they should have used 105C low ESR type), Roku have marketed a unit that was bound to fail by poor engineering design.]
Whilst I would agree that excessive running temperature is the major cause I am not sure that cheap underated capacitors are that significant. I had a total power supply failure about two months ago and replaced all of the capacitors with 105C low ESR components. However last weekend the power supply 'died' again
Upon examination the 220uF 35V post rectifier capacitor on the 9V part of the PSU had expired. All of the other capacitors, including the 100uF cap on the 9V O/P showed no change. Others have said that the continous drain on the 9V rail is of the order of 500+mA whilst the specification on the OEM board is only 350mA. This means that although the voltage specification on the capacitors, 35V is fine the ripple current exceeds the ratings of most 220uF capacitors, the situation being worsened by the excessive temperature. I have replaced the capacitor again with another 105C low ESR component from a different manufacturer but am not hopeful of a long life. It may be that high ESR capacitors might have been a more relaible choice !
A couple of people have commented that 240V mains might have increased the failure rate. I think that although the primary switcher might generate a little more heat this is of second order as the majority of failures are on the low voltage, 9V side of the PSU. In my opinion all soundbridge radios with original power supplies will be doomed to fail.
The only reliable long term cure is to replace the PSU, there are good switching power units with similar power output around but finding the right one and soak testing it in the soundbrige case could take a lot of time.
It is also particularly anoying that this forum is monitored by Roku employees who are either not passing this information to their management or that the Roku management are remaining silent to cover their back-sides.