"b" wrote in message
...
On 23 ene, 04:51, "G B" wrote:
Hi,

I have a Sony SLVN750. It failed such that it had no time display and
would no longer power up when pressing the power switch. I tore it
apart
and "shot-gun" replaced the nine capacitors in the general area of the
power
supply with capacitors of the same value. It now will power up and
even
play a tape BUT when it is powered down (in standby) the display blinks
on
and off. It seems the power supply is cycling on and off. Any idea
what
would cause this? Any help is appreciated...


"G B" wrote in message
...
The display isn't flashing per say...

The display goes blank after the supply apepars to shut itself down. It
returns after say 500 msecs.. then stays on for about a second.. then goes
blank and starts again. Also every time the display blinks, the carriage
motor appears to go through its position check...
I did replace the all the "big" electrolytic caps.. the largest were a
couple of 1000uF... I suspect that section of the circuit is working
properly.. I think there must be a standby power section of the circuit
which is toast... any ideas?


Have you replaced any electros in the front end or were they all secondary
side ? This sort of odd behaviour in switchers can be symptomatic of small
caps - often only from 1 to 47uF in value - situated around the oscillator /
control IC having gone high ESR. You will often find them located close to
some other component or heatsink, which runs hot. Do you have an ESR meter ?
Just as an aside, it makes a thread and the replies much easier to follow if
you bottom-post rather than top. :-)

Arfa