Benq T905 power supply repair
Jeroni Paul wrote:
** If the mosfet blew, R615 must have too.
Did you maybe replace it with a wirewound type ?
That would explain most of you symptoms, running OK at low loads but failing if the current in the switch is higher - also made worse if the AC supply voltage is lower as it will be with a lamp in series.
R615 ( 0.22 ohms 2 watts ) must be a metal film or composition type.
IOW *low* inductance is crucial.
Thank you Phil.
The resistor you mention was good and is the original.
Finally I got it working by wiring 4 100W bulbs in parallel,
so I removed the bulbs and all is fine.
** That SMPS is unusually sensitive to low AC supply voltage.
Normally they work from 85V and up.
..... Phil
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