8 Oct
2011
8 Oct
'11
10:14 p.m.
On Sun, Oct 9, 2011 at 3:28 PM, Chuck Guzis <cclist at sydex.com> wrote:
On 8 Oct 2011 at 20:56, Geoff Reed wrote:
> looks like all 4 diodes are blown in half or burned in half from what
> i could see.
the fault vaporized the solder so the diode remains are wobbling
about, a sharp tap and they would be loose inside the case. I wonder
if the design relies on the transformer to seal off the mains voltage
side? as it is a very snug fit.
Does the transformer have a thermal overload cutout?
?These things
look like tiny capacitors or resistors and are designed to blow
(permanently) if the temperature exceeds a certain point. ?They're
required by most electrical codes in portable small appliances, such
as hair blow-dryers.
I uploaded a couple more pictures, one shows the track lifted on the
underside of the PCB. Another shows the X2 across the mains but I
don't see any other components which might provide the thermal cutout.
The transformer itself appears to my untrained eyes to look ok, if it
has been severely stressed (damaged) should I expect to see any
visible sign?