Vizio VL260M takes time to warm up

[DakotaKid]

When first powered on it has the gray screen and some vertical lines and some blotches. Backlight comes on and stays on so no issue with the inverters or backlights. After 20-30 minutes of being on, the picture comes in perfect and no further problems. Seems like something is having to warm up or maybe a solder joint expanding until it makes contact. Power supply and mainboard pix attached. Power supply voltages seem to be normal though I don't have a SM for this TV. Pins 1&2 on the PS small connector read 2.87V and 2.92V. On the larger PS connector pin 1 is 2.77V and 2,3,4 are 12V and 9, 10, 11 are all 5V.

I am getting voltages from the the 1117 LDO's and the two transistors or voltage regulators and will post those shortly. I haven't tested extensively yet but it seem when I poke around some of those components that the screen comes to life sooner. More on that later. The caps on the power supply are rubicon, on the mainboard they are several different generic and/or cheap no name brands. Maybe some ripple current??

More to come but meanwhile if there are any suggestions on what else I should check for or test please let me know.

Thanks.
DK

[budm]

Re: Vizio VL260M takes time to warm up

Check any voltage regulators on the T-CON board yet, at the T-CON fuse?

[DakotaKid]

Re: Vizio VL260M takes time to warm up

Added picture of T-con. Voltages on the large regulator are (top to bottom in pic) 0V, 1.7V, 3.23V just after turning the set on while the screen was still gray with lines and didn't change when set was operating properly about 25 minutes later.

And, ooops, I accidentally pulled in the wrong mainboard picture yesterday. I have attached the correct image to this post so please disregard the mainboard pic in the OP. I don't know how or if I can delete/replace that image.

The top ground/adj leg of the uppermost regulator in the picture (marked in red) does something that seems odd. When I put my DMM probe on it, it reads 1.7 or 1.8 for a brief instant then jumps to 10V for an instant then settles back to a very steady and stable 2V and remains there. It does this every time I touch it with my probe. I don't know if it is just that sensitive to the DMM or if it is something of concern. The markings on it are 1084 and 0849IL so I am thinking it is a 5V input adjustable output 5A current limiting LDO regulator LM1084.

[budm]

Re: Vizio VL260M takes time to warm up

It sounds like its time for using cool spray to cool down components after warm up, you can use canned air-duster by just using it upside down.

[DakotaKid]

Re: Vizio VL260M takes time to warm up

It sounds like its time for using cool spray to cool down components after warm up, you can use canned air-duster by just using it upside down.

yep, good idea. I tried a heat gun to try to get it to come on quicker but the heat is slow acting and heats up so much around the target area that it is hard to determine what did the trick.

thanks budm.

[retiredcaps]

Re: Vizio VL260M takes time to warm up

When I put my DMM probe on it, it reads 1.7 or 1.8 for a brief instant then jumps to 10V for an instant then settles back to a very steady and stable 2V and remains there.

Do you have a multimeter with a digital bargraph? Or a multimeter with min/max functionality?

[DakotaKid]

Re: Vizio VL260M takes time to warm up

Nope, no Fluke points for me. I can probably borrow one from a buddy of mine this weekend that at least has min/max. Dang I need an oscope.