I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

[Michale32086]

Time ta teach an old dog a new trick...

I's a 25" LCD TV/Monitor.. Powers up, display looks great, but then it shuts off after a minute or so...

No blown caps, no grossly burnt areas...

I have the back off and the probes ready... Is this a candidate to check out the Rigol???

[selldoor]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

Should have spent your money on a camera!

[Michale32086]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

hehehehehehe

Yea, I am using my smartphone.. Normally it takes pretty good pics..

[selldoor]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

Have another go then or at least tell us the board numbers

[Michale32086]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

Here ya go...

[selldoor]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

When you say it shuts off after about a minute is that just the panel or the does the whole set go off? What does the power led do? Does it flicker then go off? Do the lights go off first
then the power led?

[Michale32086]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

The display just shuts off. The LED remains green and steady.. If I turn it off, then turn it back on, it comes on but then the display blanks out again after a few seconds...

What's really wierd is when I first hooked it up this morning, it blinked off twice like it does. I turned it off, then on and it worked fine for an hour or so...

[selldoor]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

May have more than one problem - if you google the power supply there are loads of hits for repair kits - 9 caps for this board. Always a good/bad sign. That would be for the worked fine for an hour when warmed.
But the going off after a few seconds - and just the panel - may be a lamp/transformer.

Perhaps have a look at replacing the caps to give it a level playing field. If you find a kit off ebay SG Hill may come up - he is friend of budm so caps are good.

[Michale32086]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

Thanx... I'll check definitely check into the repair kits

[selldoor]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

I know you want to play with your new toy but as I dont have one dont know what you
use it for I do know you have to know how to set them up so you dont electrocute yourself.
Also see here - https://www.badcaps.net/forum/showth...ht=I-INC+iH252. Perhaps before buying caps price up transformers and bulbs - unless you want the practice it may not be worth the cost of parts. You can test the secondary windings on the
inverter transformers - I dont know the pinout what is their part number. Meter on ohms 2000 no power to the board/set. If they are ok have you any spare bulbs/ monitors/laptop screens you can substitute for the lamps. Failing that see budms signature files on making up a test lamp.

Also check resolder high voltage joints on transformers and those little blue
high voltage caps between the transformers and the bulb sockets

[Michale32086]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

Well, it doesn't appear to be a heat issue.... I put it in a.. ahem.. cold box for a few minutes and when I hooked it back up it didn't stay on any longer...

That thread was a big help.. It's beginning to look more and more like it's a bulb issue. Which is not a good candidate, I guess, for my new toy..

OK, I just turned it off and then back on and the display is staying on...

Maybe it's haunted...

[Michale32086]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

I know you want to play with your new toy but as I dont have one dont know what you
use it for I do know you have to know how to set them up so you dont electrocute yourself.

I am very interested in that.

You can test the secondary windings on the
inverter transformers - I dont know the pinout what is their part number. Meter on ohms 2000 no power to the board/set. If they are ok have you any spare bulbs/ monitors/laptop screens you can substitute for the lamps. Failing that see budms signature files on making up a test lamp.

Awww, crap.. Left my voltmeters at the shop.. Unless I can use the Rigol, checking voltages will have to wait til tomorrow..

Also check resolder high voltage joints on transformers and those little blue
high voltage caps between the transformers and the bulb sockets

THAT I can do...

Thanx for the replies. Very much appreciated...

[selldoor]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

Remember I dont have one and others will be better informed to advise but just in case you are tempted, I think (and maybe wrong but )you cannot (should not )attempt to test anything connected directly to the mains this is covered very early on in the manual?.
You need to operate through an isolation transformer - I think either the item you are working on or the Rigol or both??

[Michale32086]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

Yea, good advice.. LAST thing I wanna do is frak it up before I even get to use it.. I'll hang tight til someone who knows what they are doing chimes in

I did resolder the transformers and caps.. Powered it up and the display held for a few minutes.. But then back to the same ol same ol...

[selldoor]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

Hmm no helpers eh! I left off hoping you would get some tips on using the Rigol
Perhaps start a new thread in general electronic questions. I will look in later
maybe you will have your meter to hand.

[Michale32086]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

Yea, I am going to the shop today. I run the security surveillance system for the flea market and I am updating their cameras today.. All 30 of them.. Oh joy..

I have a nice 46" Plasma (I think) that looks in immaculate condition but was the victim of a lightning strike. No obvious burns or blown caps or parts..

So it might be a better candidate for a Rigol Test Subject..

[selldoor]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

What was the part number on the inverter transformers? and can you post a good well lit picture of the back of the board and a closer in one of the area at the back of the transformers.

[Michale32086]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

Here's a pic of both..

[selldoor]

Re: I-INC iH252 LCD Monitor. Powers Up, Display Good, Shuts Off After Minute

Hmm - cant find much on the transformers (that may be good suggests they may not fail too often.
On the attached I have marked what I think are the secondaries - if you have resoldered you may have burnt off the laquer if not you may need to scrape down to the joint. Meter on ohms test S1 to S2 and S3 to S4

In the pink boxes are/were mosfets are yours part number AP9973GH if not can you read what they are?

In the next photo marked in red are two fuses - can you test those.
Meter on ohms should be same as holding probes together