sl65/12 is dead!

[gcos]

Hi to all on this brilliant site. Could someone offer guidance please (have searched but could not find similar prob).
Have this unit about 18 months - has been working perfectly. Last week it started acting as if power supply was unplugged and then plugged straight back in - it would return to the channel I was watching just before it cut off. Then it suddenly stopped working completely and won't do anything since. No sign of lights on the display, power supply says it is getting 12.2v. When it was giving trouble, there was a slight hissing noise from the back left hand corner, but as the power supply is external 12 volts I can't imagine what this is. Took the covers off and inspected - absolutely no sign of burning or badly soldered joints. Any ideas, and thanks for any help offered.
Gerard

[gcos]

Found the problem! This may help someone in the future in similar circumstances.
Unfortunately I bought a new unit before I discovered what was wrong. I bought another Sl65/12, plugged it in, and away it went. Then I decided just for the hell of it to plug the old box in (using the new power supply) - it worked. I checked the old power supply again, and its giving out 12 volts, so that why I discounted the power supply as the problem the first time.
It must be that when the load of the unit is put on the old power supply it breaks down, but when tested with a multimeter which draws little or no current, it shows 12 volts available.
Anyway, As above, hope this helps someone in future.