FS Scaleoview T17-2: inverter pumps for two times before silence

[teslacap]

Hallo,

after I got this monitor, I found that the inverter is pumping. High voltage tries switch on for two times an then silence. The switching MOSFETs FDS6612 and FDS4435 seemed okay when tested in preliminary examination procedure (no drain-source short on ohm-measure). I replaced the two big 220uF caps without any better result. Does anyone have this monitor repaired before?

Cheers

[jetadm123]

Re: FS Scaleoview T17-2: inverter pumps for two times before silence

Assuming you're getting the correct voltage from the external power supply, try performing a resistance check on the secondary windings of the two inverter transformers. They should be within approx. 3% of each other.

[teslacap]

Re: FS Scaleoview T17-2: inverter pumps for two times before silence

Hi jetadm123,

when the monitor is switched on, the PS-voltage decreases from 19 to 17 V,
during the inverter tries to start. Between those 3 pins of transformer-secondary I measure nothing (even in M-Ohm range), might be some
circuit inside which perhaps interrupt direct galvanic connection or
both transformers are secondary open burned? The CFL short lights up!
In this case there must be a flash between the open wires? Hard to imagine..
Without schematic not really fantastic working.

Cheers

[teslacap]

Re: FS Scaleoview T17-2: inverter pumps for two times before silence

is self-evident, that the ohm measurement only took place while the monitor was turned off. So, my ohm meter is not blown.

[retiredcaps]

Re: FS Scaleoview T17-2: inverter pumps for two times before silence

Between those 3 pins of transformer-secondary I measure nothing (even in M-Ohm range), might be some
circuit inside which perhaps interrupt direct galvanic connection or
both transformers are secondary open burned?

When I can't easily identify the secondary pins, I resort to all possible pin combinations test as documented below.

https://www.badcaps.net/forum/showpo...6&postcount=20

[teslacap]

Re: FS Scaleoview T17-2: inverter pumps for two times before silence

that was quite be done, I'm no beginner..
I think the secondary wires are not connected directly to this outgoing-pins
such hybrid smd-circuit might be a little different.

[kbuzov]

Re: FS Scaleoview T17-2: inverter pumps for two times before silence

hi,You can see this link
http://www.flickr.com/photos/kuvakke...7625457805926/
, it may be useful.

[budm]

Re: FS Scaleoview T17-2: inverter pumps for two times before silence

The wires on the transformer, either primary or secondary, are connected directly to the pins of the transformer. What is the P/N as printed on the transformer? You can also trying test lamps to test the inverter function since bad lamps/ wiring can be bad also.
http://s807.photobucket.com/albums/y...g%20old%20CFL/