Mag LT916s Model 900p 19" LCD dropping like flies

[created2praise]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

ok I'll try to post a pic.. I also tried to sneak in the forums of bad manufacturer of caps and found "ROBICON" in there.. This was disappointing. Don't know where I could find good quality caps here.

Thanks for the help.

[EGuevarae]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

ok I'll try to post a pic.. I also tried to sneak in the forums of bad manufacturer of caps and found "ROBICON" in there.. This was disappointing. Don't know where I could find good quality caps here.

Thanks for the help.

Digikey.com ?

[save_me21m]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

hi to all who put up this great site..i really find it really helpful since we all share a common interests about fixing things..well for a start, im a noob, got this problem about my MAG LB-906AW 900W 19'', i read all the details about changing caps, gladly i saw that Xunda is on the red list, so i bought some caps on an elecronic store, caught at a wrong time coz there were no available Rubycon caps on stock, and thought over that i would change it back again when the Ruby's are available, just wanted to make sure that these caps are the culprit on my Mag, then i decided to change all the following caps since it was all the right thing to do, the old xunda caps had no visual indications of burnt, leaked nor buldging signs still i decided to go for the new caps i bought. i recapped all of these = 680uF 25v (4pcs), 470uF 25v (2pcs), 220uF 25v (3pcs), 22uF 50v (1pc), 10uF 50v (1pc), still had the same problem as those who shared theirs in this same thread, the display stays for only a few sec then turns black still LED light stays green..surely i didnt made any mistakes upon recapping..any suggestions would really be appreciated upon this matter..sorry for my bad english..im a Filipino..had to dropped here where all the experts started as noobs..pls do guide me and direct me to the right way..im a bit lost now..

thanks a million

[EGuevarae]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

hi to all who put up this great site..i really find it really helpful since we all share a common interests about fixing things..well for a start, im a noob, got this problem about my MAG LB-906AW 900W 19'', i read all the details about changing caps, gladly i saw that Xunda is on the red list, so i bought some caps on an elecronic store, caught at a wrong time coz there were no available Rubycon caps on stock, and thought over that i would change it back again when the Ruby's are available, just wanted to make sure that these caps are the culprit on my Mag, then i decided to change all the following caps since it was all the right thing to do, the old xunda caps had no visual indications of burnt, leaked nor buldging signs still i decided to go for the new caps i bought. i recapped all of these = 680uF 25v (4pcs), 470uF 25v (2pcs), 220uF 25v (3pcs), 22uF 50v (1pc), 10uF 50v (1pc), still had the same problem as those who shared theirs in this same thread, the display stays for only a few sec then turns black still LED light stays green..surely i didnt made any mistakes upon recapping..any suggestions would really be appreciated upon this matter..sorry for my bad english..im a Filipino..had to dropped here where all the experts started as noobs..pls do guide me and direct me to the right way..im a bit lost now..

thanks a million

You might have bad lamps (CCFLs) in there...

[save_me21m]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

would you pls guide me how to change it? i know not how to change these "bad lamps" you're referring. a guide would really be helpful since im not that really familiar with these things. i just had my 1st recapped..though am not that good at soldering, i was careful (really careful) changing the caps..now these CCFL isn't gonna be that simple but i'm really willing to change it if i have to..i just need some details on what ccfl i should use? are they all the same colors after removing the phosphor coated glass tube? if so, then any ccfl would work despite the colors right? i might as well google it coz i dont even know how to take off that lamp from the glass tube..


thanks a million again kind sir's..

[geos]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

Thanks ! i replaced c10 and c11 and monitors works again
many thanks

[barry wilkins]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

I have the same problem and have replaced 6 x 470MFD and 1 x 220MFD capacitors . checked the BRI which is at 2.75 V ,and connected B.L. ON to 5V .Dissconnected the 2 BL tubes ,so it cannot be too much current .I can see the bias dissappears on the 2 power transistors ,for some reason the TL494 IC is stopping .I wonder if it have a start up cct.?
Has anyone got any schematics of the Back Light Inverter ?
I might have to break out my Tek oscilloscope and start looking .

Barry Wilkins

[EGuevarae]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

I have the same problem and have replaced 6 x 470MFD and 1 x 220MFD capacitors . checked the BRI which is at 2.75 V ,and connected B.L. ON to 5V .Dissconnected the 2 BL tubes ,so it cannot be too much current .I can see the bias dissappears on the 2 power transistors ,for some reason the TL494 IC is stopping .I wonder if it have a start up cct.?
Has anyone got any schematics of the Back Light Inverter ?
I might have to break out my Tek oscilloscope and start looking .

Barry Wilkins

2 BLs out, or just one, from the set of four (2 BLs up, 2 down), and the inverter will shut itself off. You have to test with all the lamps connected.

[barry wilkins]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

I have got to the bottom of this ,after I got one of scopes out (PM 97) the output of the TL 494 IC was disappearing .The IC seems to crash easily ,I think the oscillator on pins 5&6 actually stops.
I cleaned the whole board with an aerosol of PCB cleaner and heated up the PCB up with a small craft heat gun to quite hot .
I fitted a 0.01 mfd capacitor across the IC pins 12 to 7 to decouple the VSS supply ,because I felt the cause of the IC stopping could be interference based
The monitor now runs for all day with no sign of the backlights cutting out.
I found out this LCD display was made by Proview.

Barry Wilkins

[steven.va]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

Sorry for kicking an old thread.

I just fixed a 17" Medion TFT (Sold by ALDI* in Europe)
It uses the same Mirage AD-1700 board

The six caps 470uF@25V were bulged, and the 220uF one too.
I replaced those, plus the two small 100uF ones too.

Reassembled everything, and the LCD monitor works fine!

Greetings,

S.

* ALDI is a well known EU-discounter. (WallMart/...)

[FIXITNOW]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

Medion model number was ?

[steven.va]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

Medion model number was ?

This is the model number:
MD-30917



Greetings

[FIXITNOW]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

CHEERS
Helps keep my database in some sort of order
its always usefull having
maker
model
fault
circuit Reference ie C111 etc
component value voltage and size etc
all the best vince

[steven.va]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

No problem!
Symptom were the same as the other owners: would not startup, shutted itself down.

Greetz,

[plainhavoc]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

Vince88, I have a 700p that works the same as everyone elses... it doesn't, well. My board is burned at (U101) on the back side, the IC has 8 conductors. My idea is to omit the inverter board altogether, and run a case mod with the PSU powering the monitor. Any idea on the pin-outs running to the video board? It is the 10 conductor set on the corner near the smaller cap cluster. Any help on this would be greatly appreciated.

[MDOC]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

phubar don't use crap from rat shack unless you just want to do it over later and possibly kill the board. To order from digikey use caps from this thread.

https://www.badcaps.net/forum/showthread.php?t=1822

mostly blank pages due to geocities shutting down

[MDOC]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

BTW, I recommend Photobucket for image hosting. Free account (limit: 500MB storage, 10GB bandwidth), but a paid account is available (unlimited storage and bandwidth).

[PlainBill]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

BTW, I recommend Photobucket for image hosting. Free account (limit: 500MB storage, 10GB bandwidth), but a paid account is available (unlimited storage and bandwidth).

That of course is useful only so long as Photobucket is operational. Fortunately, a better answer is in the FAQ.

PlainBill

[MDOC]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

That of course is useful only so long as Photobucket is operational. Fortunately, a better answer is in the FAQ.

PlainBill

I see, I didn't know you have your own server for image hosting.

Anyway, yes, Photobucket has had downtimes before, but not for too long, I think... anyway, I'll use your host for my images; it's faster. Thanks

[mjbattmer]

Re: Mag LT916s Model 900p 19" LCD dropping like flies

Okay, I'm a newbie on this forum and I'm sure you all wish this thread would go away, but this is the main reason why I signed into this forum:

I too, have the problem of my Mag LT916s monitor turning off after 2 seconds.

I replaced all 6 of the 470uf 25v caps as well as the 220uf 25v cap and I still have the same problem. Even though none of the caps exhibited the tell-tale bulge and/or leakage. I thought this to be a cost-effective place to start. All the caps were soldered in properly without any shorting.

I have looked through the threads on this subject, albeit more like "skimming" through and I would like to know what is my next step?

I also want to thank all of you for your help in this matter. This is a great forum!

Mike