aaronferrucci wrote:DeepCrimson wrote:Hi!
My Roku is dead too
Support asks to send it back for replacing. But I live in Russia and post service will be cost too much, more than Radio itself.
I've tested voltage
With load (plugged into front unit)
+5.45 - 5.55
What radioelement should I replace ?
Sounds like the same problem I just had; have a look at this photo and others in the same set:
http://www.flickr.com/photos/aaronferru ... 593223550/
Be warned that opening up the R1000 for a power supply repair is not a trivial task!
Like almost everybody else my Soundbridge died a couple of weeks ago after 13 months of opertion. Althought I haven't done a lot of electronic repairs for 20+years (used to repair radio/TV to pay my way through college) I decided to fix it myself. I followed the guide set out by others on this forum and back up the comments that dismantling the PSU takes a LOT of care and patience. Also when you have the PSU apart TAKE CARE as there are parts of the unit that are live to 240V mains.
However when you have got the PSU board exposed the repair is relatively trivial. I replaced the 220uF 35V capacitor as per the flickr picture above and the radio did spring back into life.
However; when off load the PSU voltages were unstable, ~10.5 and 22v.
On advice from Pete G0KPH I then checked all of the other electrolytic capacitors on the board. Most were within spec although all on the low side but the small 47uF 16v cap in the HV part of the PSU had reduced to 27uF. ie heading for failure Replacing this cap brought the O/P voltages back down and far more stable. As the high running temerature and continous operation of this PSU will have used up most of the lifetime of all electrolytic capacitors I replaced them all with 105C low ESR units. I also replaced the 75R resistor with a higher wattage unit.
Incidently my 9.5V rail still measures 9.55v off load and 9.1V under load.
So thank you Pete and everbody else who has provided helpful information on this forum.
As a professional engineer with many years experience I consider that the Soundbridge radio is a unit where the power supply is bound to fail on a regular basis. Because of the total lack of thermal management which is mainly due to the plastic box and tape around the box the components on the PSU, which is always on, run at an excessive temperature. Back of the envelope calculations suggest the mean time to failure will be in the order of 7 months! Even with the higher rated replacements I have only improved this figure by about a factor of three.
Great gadget, fantastic sound quality but CRAP engineering.