AG Neovo E-17DA

[sabre504]

Hi need a bit of help if possible .
Have taken the inverter board from this AG Neovo E-17DA
only to find in picture one that someone has changed 2 of the caps for 63v 220uf whilst the others (still glued) are 25v 220uf Capxon.
I assume they should all be 220uf 25v 105c.
Also the 2 green fuses are blown so i need to change those.

Picture 2 is of the opposite side and this is where i need the help, one of the
transistors has burnt out (STU2040PL i have attached a datasheet )

I cant seem to find a match and was wondering if anyone else had dealt with one of these and knew of a match .

I have done searchs and checked lots of data sheets but there are so many variations i must admit i am getting a bit lost and until i can sort the power board i cant move on to test the rest of the monitor.

Any input i would be grateful

[jetadm123]

Re: AG Neovo E-17DA

Fairchild shows a FDD4243 as a possible substitute for the STU2040. And International Rectifier shows a IRF5305 as a sub for the FDD4243. There are differences in the current and Rds ratings, but the 20A the STU2040 is rated at is a bit of an extreme anyway.

[sabre504]

Re: AG Neovo E-17DA

Thats great thankyou have ordered them now just gotta find the right fuses
and change the caps

[sabre504]

Re: AG Neovo E-17DA

Ah well got the parts i needed only to find when i started to change the blown part that it had taken out the track beneath .

Now think better off trying to find another inverter board than rescue this one ,but will keep it for parts that may be useful.
I have some universal inverters but i think wiring one of these in would be a pain as would have to get a 12v supply to it first, then sort the other wires.

Thanks for the help

[sabre504]

Re: AG Neovo E-17DA

Futher to earlier post i reassembled the unit after solering on some 4 amp fuse wire to the old fuses (not ideal i know) so i could try to measure voltages on the wiring.
Even though the transistor is not in circuit suprisingly the screen flicked on then off so bulbs ok and vid card seems ok.

Now my question is if i work out which wires supply the inverter power and connected them to another inverter (universal one i have) do you think the sense circuit would still shut the monitor down

Picture shows caps with power going to them

3 reds = 12v
1 yellow = 5v

[retiredcaps]

Re: AG Neovo E-17DA

Even though the transistor is not in circuit suprisingly the screen flicked on then off so bulbs ok and vid card seems ok.

Now my question is if i work out which wires supply the inverter power and connected them to another inverter (universal one i have) do you think the sense circuit would still shut the monitor down

Yes the sense circuit could still shut the monitor down because the ccfl tubes or the wiring could be suspect. Your observation that the screen flicked on then off could indicate a dying ccfl tube or bad wiring.

[sabre504]

Re: AG Neovo E-17DA

Tested tubes with another inverter board (trusty old xerox unit)
The screen flicked on and off again because i could not replace the
STU2040PL P channel transistor as the pad is trashed .
Just thought there may be a way to use another inverter to bypass the sense circuit using the wiring that is there

[seanc]

Re: AG Neovo E-17DA

If you can work out where the pad connects to, you can run a jumper wire to the next component.

[sabre504]

Re: AG Neovo E-17DA

Dont think thats going to be possible as you can see in the picture that the main pad has burnt off and its taken out some of the tracks, also another pad for one of the legs has come off too.

[sabre504]

Re: AG Neovo E-17DA

Just an update

Picture 1
red mark soldered in a pin giving 12v DC
yellow Ground (removed brown wire to place in grond for inverter)
Green on/off (removed green wire to place in grey for inverter on )

Picture 2
Removed all transformers ccfl plugs and ballst resistors to make a clear flat area for new inverter and replaced the 2 x 220uf 63v with 220uf 25v (kept these in as they are part of the 12v circuit.

Picture 3
The almost finished product just need 2 x sticky pads to hold the new inverter in place before final assembly.

Tested and working even still have all menu controls (brightness ,osd and volume)

[bossman]

Re: AG Neovo E-17DA

We have had good success replacing the caps but have come across the same issues you had with the transistors being burnt out.

Just wondered if anyone had the part number for new inverter board or for the board you have used in your fix?

Any help would be gratefully received

[sabre504]

Re: AG Neovo E-17DA

Will dig the info out for you

[sabre504]

Re: AG Neovo E-17DA

I bought my inverter from a company called Semaforz on ebay they are based in Czech Republic they do several types.
Item number 110642904624 is the same as the one i used just a different colour .
Depending on where you are would depend on time it takes to get to you
i bought a few so no waiting .
If you need more help or info just let me know

[bossman]

Re: AG Neovo E-17DA

@sabre504:

Thanks very much

[Crauler]

Re: AG Neovo E-17DA

Hello, I've Neovo E-17DA, screen goes black in half a second.
I've replaced all four capacitors, two fuses ok, but screen still goes black in half a second.
All four transformers show 1.0 kOhm. External psu should be good.
Any ideas?

[Rtech]

Re: AG Neovo E-17DA

Two things need checking,does the Power led stay green when the PC is connected and the screen is Black ???/...and Can I assume you do not have a spare backlight to use in testing ??

[budm]

Re: AG Neovo E-17DA

Sounds like you need to make a couple of test lamps.
http://s807.photobucket.com/albums/y...g%20old%20CFL/

[Crauler]

Re: AG Neovo E-17DA

Two things need checking,does the Power led stay green when the PC is connected and the screen is Black ???/...and Can I assume you do not have a spare backlight to use in testing ??

First, backlight goes black, but video image still visible about 1 second, then power led switching to yellow and nothing visible.
I connected laptop ccfl bulb for test, it light up for half of a second, then it goes blank.

Tests, I've made:
Just in case I re-solder bad solder joint on the main coil at the bottom-left of the inverter by this manual http://bbarrington.posterous.com/neovo-lcd-repair
Checked four mosfets with multimeter, they're ok.
I opened external power adapter, there are no bad caps.

About capacitors, I used only new Panasonic, Samhwa and checked with a capacitance meter.
C41: 1000uF 10v
C43: 470uF 25v
C5 + C6: 220uF 25v

[Rtech]

Re: AG Neovo E-17DA

When you used the ccfl from the laptop to test,, this was done with all the other lamps still in situ ??? and then substituted for each of the lamps in turn,BUT all lamps must be plugged in when this is done.

[Crauler]

Re: AG Neovo E-17DA

When you used the ccfl from the laptop to test,, this was done with all the other lamps still in situ ??? and then substituted for each of the lamps in turn,BUT all lamps must be plugged in when this is done.

Yes, I use ccfl with all other lamps plugged and checked it by rotation.