Mag Innovision LT716s model 700P blanks off in 10-15 secs

[MDOC]

The monitor blanks off in 10-15 secs after power-on. I've read up a lot of posts on this model LCD monitor. Here's what I know, please correct me if it's wrong: A definite fix for a 2-second display problem is to replace the caps, but maybe not for a 10-15 second display problem. Replace all caps on the board with Panasonic FX series--they may (or may not) fix the problem, but the caps are not good caps because of heat specs.

So if the caps do not fix the problem, what else could it be?

Can you please tell me what part numbers to use to get them replaced? I've used DigiKey years ago, but I'm not familiar with their part number filter system.

Enclosed are pictures. Are there anything else to be said for this problem? I find nothing burned or bulging caps and the fuses (three of 'em) are fine.















Thank you

[PlainBill]

Re: Mag Innovision LT716s model 700P blanks off in 10-15 secs

The monitor blanks off in 10-15 secs after power-on. I've read up a lot of posts on this model LCD monitor. Here's what I know, please correct me if it's wrong: A definite fix for a 2-second display problem is to replace the caps, but maybe not for a 10-15 second display problem. Replace all caps on the board with Panasonic FX series--they may (or may not) fix the problem, but the caps are not good caps because of heat specs.

So if the caps do not fix the problem, what else could it be?

Can you please tell me what part numbers to use to get them replaced? I've used DigiKey years ago, but I'm not familiar with their part number filter system.

Enclosed are pictures. Are there anything else to be said for this problem? I find nothing burned or bulging caps and the fuses (three of 'em) are fine.

Thank you

First read this thread.

You can't use Panasonic FX series caps; AFIK, they don't exist. Nichicon has an FX series; that's an audio grade cap. Don't use that either.

Caps are one possible cause of the 'two seconds to black' issue, but not the only cause. Other possible causes are bad CCFLs, bad solder joints, arcing, bad transformers, bad diodes or transistors, etc.

I've described the mechanics of the problem countless times; if you are into self flagellation, search on my name and 'two seconds to black' and read the ugly details.

10 - 15 seconds (assuming you have timed it)* is an unusually long time for this problem. I'd first check the BL_ON signal (from the logic card to the inverter) to make sure that isn't turning the backlights off. Then start looking for bad solder joints in the inverter.

* Time estimates are highly subjective. Consider how long 15 seconds spent kissing Jennifer Aniston would seem. Then consider 15 seconds kissing Vince Vaughn.

PlainBill

[MDOC]

Re: Mag Innovision LT716s model 700P blanks off in 10-15 secs

You can't use Panasonic FX series caps; AFIK, they don't exist. Nichicon has an FX series; that's an audio grade cap. Don't use that either.

Caps are one possible cause of the 'two seconds to black' issue, but not the only cause. Other possible causes are bad CCFLs, bad solder joints, arcing, bad transformers, bad diodes or transistors, etc.

PlainBill

OK, what cap series is recommended?

[PlainBill]

Re: Mag Innovision LT716s model 700P blanks off in 10-15 secs

OK, what cap series is recommended?

I personally prefer Panasonic FM or FC series in that order. I'm not afraid to let availability override preferences. I've got Nichicon, United Chemi-Con, and even a few Rubycon on hand. There is a thread in the FAQ 'What capacitors should I buy' that lists a number of highly reliable brands and series. Note that contrary to common practice, the best caps are last (furthest to the right) on the list. It's been asked many times; no there is nothing wrong with mixing brands and series of caps. And I wouldn't be surprised if in the last 4 years new series of caps have been released with even better characteristics.

PlainBill

[MDOC]

Re: Mag Innovision LT716s model 700P blanks off in 10-15 secs

Got it working!

1. Re-Soldered both transformers.
2. Re-Soldered any joint that looked cold under a magnifying glass.
3. Replaced the following caps:
2 - 10MFD 50V C3, C25 5mmx11mm P10316-ND
2 - 100MFD 35V C10, C11 8mmx12mm P10294-ND
6 - 470MFD 25V 10mmx16mm P10275-ND
1 - 220MFD 25V C219 8mmx12mm P10271-ND
1 - 47MFD 50V C203 6mmx11mm P10321-ND
1 - 100MFD 450V C201 22mmx30mm P14100-ND (bus wire required for leads)

That was it. Put it together (partially) to see if fixed. Still running good. Fixed!

[MDOC]

Re: Mag Innovision LT716s model 700P blanks off in 10-15 secs

I removed the LCD to put more screws into the chassis, then put the LCD back in, powered it up, and then nothing is displayed except the raster. Green LED remains lit. Does this mean I have damaged the LCD itself? Does this mean the LCD just went bad all of a sudden?

[MDOC]

Re: Mag Innovision LT716s model 700P blanks off in 10-15 secs

One more thing... while powered up, if I lift up the LCD panel a bit from the enclosure, the display turns white. Put it back down, it goes back to normal raster display but with no picture display.

[Scenic]

Re: Mag Innovision LT716s model 700P blanks off in 10-15 secs

check the cables (esp. the flex(?)cable going to the display (not the lamps))

[MDOC]

Re: Mag Innovision LT716s model 700P blanks off in 10-15 secs

check the cables (esp. the flex(?)cable going to the display (not the lamps))

Thanks... you are right! Fixed again... displays well.

[Mikie19598]

Re: Mag Innovision LT716s model 700P blanks off in 10-15 secs

Got it working!

1. Re-Soldered both transformers.
2. Re-Soldered any joint that looked cold under a magnifying glass.
3. Replaced the following caps:
2 - 10MFD 50V C3, C25 5mmx11mm P10316-ND
2 - 100MFD 35V C10, C11 8mmx12mm P10294-ND
6 - 470MFD 25V 10mmx16mm P10275-ND
1 - 220MFD 25V C219 8mmx12mm P10271-ND
1 - 47MFD 50V C203 6mmx11mm P10321-ND
1 - 100MFD 450V C201 22mmx30mm P14100-ND (bus wire required for leads)

That was it. Put it together (partially) to see if fixed. Still running good. Fixed!

I have replaced all of the caps but i still don't get any video i was getting about a 2 second one before i replaced the caps but i didn't resolder the transformers but i get a Green light showing it is on and getting a signal

[PlainBill]

Re: Mag Innovision LT716s model 700P blanks off in 10-15 secs

I have replaced all of the caps but i still don't get any video i was getting about a 2 second one before i replaced the caps but i didn't resolder the transformers but i get a Green light showing it is on and getting a signal

There is no extra charge for punctuation. Used properly it would really make your stream of consciousness easier to understand.

1. Hook the monitor to a working computer. Do you see an image on the monitor if you shine a flashlight on the screen?

2. Check F2

3. Note the links in my signature. Good quality pictures of the top and bottom of the power supply will help. Use 'Manage Attachments', do not post inline.

PlainBill