The servicing manual for Viewsonic monitor e70f can be found at the
following site
ftp://147.213.74.111/Schemy/Monitory/ or other monitor
schematics can be found at
http://schema99.host.sk/my_page/monitory/b.htm.
According to Page 27 of the servicing manual for viewsonic e70f for no
power supply dead set.
I checked the fixed output voltage after the transformer there was
nothing no dc voltage at all.
I checked the C807 capacitor and there was a dc voltage of around
320Vdc
as the input supply is 230Vac which should be right as it is twice as
in the example for input supply 110Vac(US) should be 150Vdc.Even with
no power supply there is still this 320Vdc across it.
I then checked the resistors R819, R805 & R829 which is ok no open
circuit
The funny thing is the Q805 n-channel power mosfet Fuji 2SK2645-01M
with the very large heatsink on it. The resistance across the
source(black -terminal) and drain(red +terminal) is 0 ohm and the
resistance between the source(black -terminal) and gate(red +terminal)
is 0 ohm. Is this right? or do I have to take out the mosfet from the
board in order to check??I,m thinking of replacing this component.
The IC801 pin7 is 0V.
How to remove this mosfet from the board? I have a desoldering tool
and iron and wick. The large heatsink seems to be glued onto the board
by some white mixture and screwed onto the mosfet tightly.
I can,t get to the component or unscrew the heatsink cause there are
lots of short wires connected to the board and the CRT. Can any
experienced monitor technician please advise a newbie on how to
replace such a component and is this the right action to take.
Bob Parker wrote in message . ..
"Thias Russell" wrote:
Hello Steve
First of all it is normally the power supply that is faulty when there is no
led on. So in that case it could be faulty cap. faulty swich transistor and
so on.
I have a 40 page service manual as PDF file if you are interested.
If so please Email me at:
Best regards Thias Russell
Just for the information of anyone seeking this manual, Thias is
*selling* it for the price of 50 Danish crowns, not giving it away.
Cheers,
Bob