Identifying TV capacitor MMKP82 683K630

[NeedsHelp]

I didn't want to bore everybody with a long post so below I listed the short of what I'm asking, but I also wanted to provide details in the long below. Thanks

Short:
I need help on identifying and replacing a capacitor and also finding if there is a way to test it in circuit.
I am looking at a capacitor that is a little gray box, on top of it is written:
MMKP82
683K630

And what does +5VMCU, CNT, PT, IS1 and IS2 mean?


Long:
I am trying to fix an LCD TV, it is an Element model ELDFW464, it comes on for a few moments and then the display goes off to blank and black I still have sound and the controls and remote work but the screen is blank and black, I've been told that this is symptoms of a bad back light inverter board, so I took the back cover off and only see two boards, the power board and the main logic board, I see NO other boards at all. Printed on the power board is: MEGMEET www.megmeet.com MIP988CF. On the main logic board is CV318H-D. You can see real good close up pictures of the front and back of the power board at shopjimmy.com

I back probed the connectors on the boards and all seemed correct (I think) except for on the power board when I got to the connector (CN4 top right corner) that goes to the back of the display panel, I don't know what I the reference designators mean and what readings I should be getting, the refdes are:
VBL+, VBL-, SGND, +5VMCU, CNT, PT, IS1 and IS2
it is an easy guess that VBL+ is "Voltage Back Light Positive" and VBL- is "Voltage Back Light Negative" and SGND is "Signal Ground" but what is +5VMCU, CNT, PT, IS1 and IS2?

After the TV display goes blank and black a green dianostic LED (DB9A) on the power board close to the connector CN4 blinks two times every four or five seconds, I have no idea what that code means. I then checked the voltage readings on the connector CN4 and I read no voltage on VBL+ or VBL-, I got 5.0 volts on +5VMCU and on CNT, on PT when I first turn the TV on it quickly goes up to 2.30 volts and then quickly goes down to 0 volts.

I took the power board off and started back tracing from the VBL+ and VBL-, on the VBL+ the first thing is a red capacitor (C142) the capacitor seems bad as I tested it in circuit with my ohm meter and it would not take a charge. Written on it is:

WFA 105K
450V

I plan on replacing it with this: Panasonic ECW-F2W105KA. The VBL- is connected to a capacitor (C140) that is a little gray box, on top of it is written:

MMKP82
683K630

I don't have a clue about this capacitor or what to replace it with. Searching on Google has not helped me at all. I don't know how to test it in circuit because it is connected to transformer ((T4) MIP988CF-T4 EC28-031 1139 01 REV.1.0) and inductor ((L11) MIP988CF-L11 EI28-014 1140 25 REV.1.10) What do the markings mean, what should I replace it with, do I have to take it out of circuit to test it? Any help???

[budm]

Re: Identifying TV capacitor MMKP82 683K630

'683K630' 0.068uF 630V, Polypropylene type.
Whay do you think it is bad? You need to remove it to measure its capacitance and leakage resistance.

But most of all, we need to see good clear pictures of the whole back side of the TV showing all the boards and good clear straight shot pictures of the whole power supply board top and bottom side of YOUR board.

https://cdn.badcaps-static.com/pdfs/...40ddc16f29.pdf

[NeedsHelp]

Re: Identifying TV capacitor MMKP82 683K630

Thanks for the quick response and information.

Do you know who makes that capacitor, to the left of the MMKP82 is <> so it looks like this: <>MMKP82.

I don't know if its bad or not, but the capacitor (C142) next to it seems bad to me because it will not take a charge and they are both connected to the same inductor (L11) as you can see in the links to the LARGE pictures at shopjimmy that I posted in my OP, so I thought I would be ready to replace both of them.

The power board looks the same as the one in the LARGE pictures in the links that I posted in my OP, I don't see or smell anything damaged. I am not at the TV now, but if you still want pictures I can be later and I'll have to replace the power board to show the board in place. The wire harness that comes from the CN4 connector on the power board is connected directly to the side of the display.

[budm]

Re: Identifying TV capacitor MMKP82 683K630

You cannot test it in circuit and capacitor with such low capacitance is not going to show charge up on the meter.
We still need pictures, and at least Voltage testing at the connectors.
There are more than one version of this TV model, your may have the inverter board inside the LCD panel.

[NeedsHelp]

Re: Identifying TV capacitor MMKP82 683K630

We still need pictures, and at least Voltage testing at the connectors.

UPDATE: I put the TV back together last night and I did the flashlight check again and I can see video, the screen still lights up for just a few moments and then goes to black but I can see video with the flashlight. Maybe it is was too light during the day for me to see the video before because I checked at night this time.


Element Electronics 46" LCD TV model no.: ELDFW464

Power board MEGMEET www.megmeet.com MIP988CF REV.1.0
shopjimmy large pictures: Front Back

My pictures below...



On connector four (CN4) what does +5VMCU, CNT, PT, IS1 and IS2 mean ??


I don't know how to make these voltage readings look better in this post, but maybe you can understand them:

CN2
RefDes Wire Voltage
+12V Red 12.08
+12V Empty 12.8
SGND Black 0
SGND Black 0
SGND Black 0
+5V Red 5
+5V Red 5
5VSB Yellow 5.03 5.08 when TV is off
PS White 4.03
+5V Red 5
+5V Red 5
SGND Empty 0
SGND Empty 0


CN3
RefDes Wire Voltage
SGND Empty 0
PS Empty 4.2
DM White 4.8
BL Yellow 4.5
NC Empty 0


CN4
RefDes Wire Voltage
VBL+ Red 0
VBL+ Red 0
- Empty 0
VBL- Red 0
VBL- Red 0
- Empty 0
SGND Black 0
+5VMCU Yellow 5.0
CNT Yellow 5.0
PT Yellow 0 Quickly goes to 2.30 then quickly to 0
IS1 Red 0
IS2 Red 0


CN8
RefDes Wire Voltage
SGND Black 0
SGND Black 0
+24V Red 23.8
+24V Red 23.8

[R_J]

Re: Identifying TV capacitor MMKP82 683K630

Looks to me like CN4 vbl+ & vbl- are h.f. ac going to the backlight board inside the panel. If the backlight board is the "Megmeet MIP466-HV Backlight Inverter" it seems to be fed with high freq. ac not dc, so the fault could be on the inverter board or ccfl lamp

[CapLeaker]

Re: Identifying TV capacitor MMKP82 683K630

These sets are cheap to fix. Look at SJ. Complete board set for 40$. Sounds like a bad transformer on the inverter board.

[NeedsHelp]

Re: Identifying TV capacitor MMKP82 683K630

Looks to me like CN4 vbl+ & vbl- are h.f. ac going to the backlight board inside the panel. If the backlight board is the "Megmeet MIP466-HV Backlight Inverter" it seems to be fed with high freq. ac not dc, so the fault could be on the inverter board or ccfl lamp

Sounds like a bad transformer on the inverter board.

So should I be able to get a voltage reading on VBL+ on connector four (CN4) if it is the inverter board or ccfl lamp?

On connector four (CN4) what does +5VMCU, CNT, PT, IS1 and IS2 mean ?

[budm]

Re: Identifying TV capacitor MMKP82 683K630

So should I be able to get a voltage reading on VBL+ on connector four (CN4) if it is the inverter board or ccfl lamp?

On connector four (CN4) what does +5VMCU, CNT, PT, IS1 and IS2 mean ?

The +5VMCU is probably for running the PWM IC on the inverter board inside the panel. IS1, IS2 are probably for the Current (I) sensing feedback signal of the Lamps' current.
CNT may be for Control, PT may be for dimming control.
Since the VBL+ VBL- are high frequency AC in the 50~80KHz range, your AC meter is probably not be able to read it due to low AC bandwidth of the meter.
BTW, so you did see the backlights come on for seconds?
What the LCD panel model number? I cannot read the sticker on the panel looking at your pictures.

[NeedsHelp]

Re: Identifying TV capacitor MMKP82 683K630

The +5VMCU is probably for running the PWM IC on the inverter board inside the panel. IS1, IS2 are probably for the Current (I) sensing feedback signal of the Lamps' current.
CNT may be for Control, PT may be for dimming control.
Since the VBL+ VBL- are high frequency AC in the 50~80KHz range, your AC meter is probably not be able to read it due to low AC bandwidth of the meter.
BTW, so you did see the backlights come on for seconds?
What the LCD panel model number? I cannot read the sticker on the panel looking at your pictures.

My meter is basic (only thing I could get), reading the meter specifications: 40~400Hz response, 600V maximum input voltage. What type of meter do I need?

Backlights have always come on for a few seconds and shows a blue screen with Element Electronics and then most of the time goes to black, but sometimes would be able to see video and/or menus for a few moments then go black. I sure thought it was blank and black before I put the TV back together.

My pictures from before I removed the power board (why oh why so many screws).
Hope this helps.

[NeedsHelp]

Re: Identifying TV capacitor MMKP82 683K630

LARGE Pictures of power supply board from www.ShopJimmy.com

Power board MEGMEET www.megmeet.com MIP988CF REV.1.0

www.shopjimmy.com large pictures: Front


Back

[budm]

Re: Identifying TV capacitor MMKP82 683K630

If the backlights did come on and then go off it can be due to bad BALANCER/inverter boards (inside the panel), bad lamp/lamps, bad power supply board.
CHI MEI LCD PANEL: V460H1-L12 rev C1

The spec sheet attached is closed enough to know what are inside the panel.
It takes the VBL of around 90VAC and step it up to running Voltage 1000VAC, see page 12.

[NeedsHelp]

Re: Identifying TV capacitor MMKP82 683K630

I'm not sure that I didn't mess something up and I know I left fingerprints but I took the display apart. None of the lights look good, they all look like they have been trying to catch fire and burn into at both ends.

ShopJimmy had (Out of stock) the inverter board for 19.98 but now I am thinking it is the bulbs and not the inverter from the way the bulbs look. On the inverter I tried checking the transformer pins in circuit for continuity, between pins 1 and 3 the meter read 000 on all of them, between the middle pin (2) and pin 4 the meter would read 508 to 516.

I have no way to check these bulbs but they all look bad and I think to be safe they all would need replacing, aren't these bulbs somewhere between 10 and 15 dollars each? If I replaced all 12 that would be 120 to 180 dollars before shipping and handling and taxes.

[budm]

Re: Identifying TV capacitor MMKP82 683K630

Lamps are in very bad shape indeed.

[NeedsHelp]

Re: Identifying TV capacitor MMKP82 683K630

Lamps are in very bad shape indeed.

Is that normal, do all lamps all go bad at the same time. It looks like they were getting very very hot almost to the point of catching something on fire! The inverter board seems fine from what I could tell.


Well it seems you need to have good CCFLs to really know your inverter is working and you need to have a good inverter to really know the power supply is working.

Whos idea was it to put the inverter board inside the display, didn't they think someday somebody might just want to check the inverter and it would be alot easier without having to disassemble the whole display.

I guess companies don't want things to be repairable so they can sell more things, if they made things that lasted forever they would quickly go out of business.

Why couldn't they just make a TV where you can get to the "Back" lights from the back without having to take off the front panel. I had to remove a lot of things from the back anyways so that I could remove the things in the front.

Looks like common sense isn't common and things could be a lot easier.

Also ShopJimmy didn't even have that inverter listed under this model.

[R_J]

Re: Identifying TV capacitor MMKP82 683K630

Did you try the tv with the lcd panel removed to see if all the ccfl's are lighting? also check the lamp connections, the heat corrodes them a bit and can cause poor connections, even though the lamps are black they should still work for a while anyway

It seems most people want cheap tv's, the mfg's build them cheap, then sell them cheap, but they don't last, people still not happy. I still say a 42" plasma should still sell for $6,000.00 then people would have no problem paying to have them repaired.

[NeedsHelp]

Re: Identifying TV capacitor MMKP82 683K630

Did you try the tv with the lcd panel removed to see if all the ccfl's are lighting?

No, before I seen the lamps I had thought about doing that but now that I've seen them I know if I was going to try and fix the TV I would just go ahead and replace all of them even if some of them worked but looked bad.

[R_J]

Re: Identifying TV capacitor MMKP82 683K630

You might replace all the lamps and find out you still have a problem with the inverter, just a thought.

[NeedsHelp]

Re: Identifying TV capacitor MMKP82 683K630

You might replace all the lamps and find out you still have a problem with the inverter, just a thought.

Yeah that is what I was think too, also after replacing the lamps if I had to then replace the inverter I also then might find out I still have problems with the power supply!

It is like a catch 22, before I would buy any parts I would want to know the new part would fix the TV but I would have to order the part to know it would fix the TV.

With this old of a TV I don't want to spend any more money on parts then I have too. If I had to buy 12 lamps and then fix or buy an inverter and then a power supply I think it would be better to buy a new TV.

It would be handy to have a section here that shows how others use basic tools like a multimeter to check power supplys, inverters, main boards and such and/or how to test components like capacitors, inductors, diodes, transformers, rectifiers and etc..

[Th3_uN1Qu3]

Re: Identifying TV capacitor MMKP82 683K630

It is unlikely for ALL the lamps to be bad, blackened ends on CCFLs are normal as they age. Since you have the panel apart, power on the TV like that and check whether there is any one of the lamps which does not strike.

If all the lamps strike and output reasonably white (read: not pink) light, it's gonna be an inverter fault. If you have lamps that do not strike replace only those and see where that gets you.