Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

[Amraks]

Hey I have Chimei CMV221D here, Have replaced all the caps out.
Symptom I was having before the cap change is the amber light would stay on.


Now here is the new symptom, getting a green led but it will turn off once there is load from the ccfl bulbs.


Not sure what the problem is.

Could it be ccfl bulbs are not good?

Thanks in advanced if you can answer this

[selldoor]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

You need to read this guide by retiredcaps start at post19
https://www.badcaps.net/forum/showthread.php?t=10419

[Amraks]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

not my problem at all.

The green led turns off and ccfl tube flickers white.

So nothing is getting a chance to display.

its cycling through this.

[selldoor]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

So what is the "Flash on screen" in the heading?
It either doesnt come on, Flashes, or stays on. which is it?
You never mentioned cycling??

[Amraks]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

its symptoms.
You plug it in goes to green bright flash on monitor led goes clear then repeats.

sorry.

also I took the ccfl cords out and it remained amber so it was doing this under load.

I went back over my solders tried fixing up the 50v 220uf solders and damn traces lifted up.

So I couldn't trace back to were they are meant to go.
I have circled it in red here the problem area.

I reckon I will have to try find a replacement board.

ps this board is someones off this site. I have no good digital camera at the moment, as the one I use usually is with my father for the week.

[selldoor]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

Pic is too small for us to be able to help much - I can only suggest you wait till you get a good clear picture (max resolution 2000x2000 and 2MB) post using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Then we can get a good look and suggest repair and then look at the starting up problem.

You do have 2 seconds to black ( It includes less than 2 seconds) so you could do some of the tests in that - Inverter transformers to start with then it would seem that it is prone to burnt bulbs - You posted Yesterday? in a thread and that has links to other threads that cover the bulbs problem so it might give you some clues how to get at them to see if they are burnt at the ends.
Perhaps if the bulbs have gone the cost of bulbs plus a possible new board (May even be required if Inverter transformers are gone) may not be worth it compared to the cost of used but working screen.
EDIT EDIT EDIT
Here is yet another board I have marked where I thin k the secondary winding pins are - POWER OFF meter on ohms 2000 test S1 to S2 and S3 to D4 I guess should be between 400 and 800 ohms.

I have also marked what i think are the pins of the problem cap.
On this pic there appears to be a trace going down under the orange zener diode - is the bottom pin in the pic the negative leg?

[Amraks]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

Thanks for the time you are putting into helping appreciate it.

bottom is negative.

About to download the trace schematic if I can navigate this Chinese site.

[Amraks]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

the monitor won't turn on. now due to them two traces.

So testing anything further is useless at this stage.

gotta wait till I get a digital back.

[selldoor]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

the monitor won't turn on. now due to them two traces.

So testing anything further is useless at this stage.

gotta wait till I get a digital back.

You may as well test the Inverter transformers - board does not need power for that.
EDIT
Pretty sure one trace goes onder that ZD to the wide ground
trace and behemot said he thought the other + end went to
the diode on the other side. I have asked the boss if he can do a picture of the area inside the yellow box so more info may follow soon.
Later Edit
He just updated his post with the info so go in and thank him

[Amraks]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

I am in business again its turning on since connecting too
empty surface mount.

I thought I screwed the zener diode also but its flashing green again. as to before nothing was happen.

here is were the trace lead too.

fine trace I may add.

will continue my testing.

[RethoricalCheese]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

That trace goes to negative side of the cap. There is another trace going underneath that diode, which goes from cap´s positive side to C115.

[Amraks]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

oh now with them inverter transformers do I take them out to test or test in circuit?

sorry for the n00b question.

do I test on ohms 200k?

[Amraks]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

That trace goes to negative side of the cap. There is another trace going underneath that diode, which goes from cap´s positive side to C115.

so that postive side doesn't at all go to that zener diode, above that lead?

as I have it?

[RethoricalCheese]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

More like @ 2k ohms.

I don´t think it is needed to test them by removing them.


Positive side goes to that diode but also goes under another diode.

https://www.badcaps.net/forum/showpo...1&postcount=78 look at this post.

I will take a picture soon.

[selldoor]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

oh now with them inverter transformers do I take them out to test or test in circuit?

sorry for the n00b question.

do I test on ohms 200k?

Test on the board using 2k ohms but the pins I marked are wrong see the boss thread.

[Amraks]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

deep breath, ok I think I understand but

trying to work out which side of C121 and R144.

here is two pictures how I am picturing it.

[RethoricalCheese]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

Second picture is correct.

[selldoor]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

It is nearest but not quite the same as the picture in post14
Amraks - did you see that picture

[Amraks]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

well I have it working now.

Thanks everyone that helped me fix this.

Celldoor for having a good look around the badcaps forums for me.

I hope this thread will help someone else.

[RethoricalCheese]

Re: Chimei - CMV221D(replaced all caps now led green then off with flash on screen"

It is nearest but not quite the same as the picture in post14
Amraks - did you see that picture

I had one thing left out in my picture. He had it corrected.