Syncmaster 2253lw inverter "not turning on"

[nickt1862]

Okay, the caps I replaced because of buldging/puffiness:
2 x 1000uF 16v by the inverters
1 x 330uF 25v
4 x 820uF 25v

The caps I didn't replace which weren't bulged/puffed up:
1 x 10uf 50v
1 x 47uf 50v
1 x 100uf 16v
1 x 100uf 450v

I know that caps that look good doesn't mean they are good and that the 100uf 450v cap has a low failure rate.

The lcd ccfl's are fine = 1000% sure of this but they are not lighting at this time.

Having said all of this by your past experiences can any of the remaining caps NOT replaced cause the lcd ccfl's not to light up?

I am ready to replace 3 of the 4 remaining for starters not replacing the 100uf 450v one - yeah watch you all say that this would be the possible culprit.

I already repaired another 22" Samsung lcd monitor which I'm using now, but this one I'm inquiring about is a tad more challeging, lol!

Any input would be greatly appreciated.

Thanks so much!

Nick

[Jasgriff]

Re: Syncmaster 2253lw inverter "not turning on"

Hi Nick,

Does the screen flick on for 2 seconds or does it not flick on at all?

And yes the other caps can still cause problems even if they are not showing bad signs as you said. I think most would eliminate that risk by swapping them.

[retiredcaps]

Re: Syncmaster 2253lw inverter "not turning on"

The caps I didn't replace which weren't bulged/puffed up:
1 x 10uf 50v
1 x 47uf 50v
1 x 100uf 16v
1 x 100uf 450v

1) The 47uF 50V is probably your startup cap. It helps the SMPS startup properly.

2) If this was my monitor, I would have replaced the first 3 and left the big filter cap as is (100uF 450V).

3) If the backlights are not coming on and you have proper DC voltage to the inverter section, then you could have a blown fuse and/or shorted out mosfets/transistors in the inverter section.

[nickt1862]

Re: Syncmaster 2253lw inverter "not turning on"

Hi Nick,

Does the screen flick on for 2 seconds or does it not flick on at all?

And yes the other caps can still cause problems even if they are not showing bad signs as you said. I think most would eliminate that risk by swapping them.

Jasgriff,

Nope, no flickering at all.

All the caps on this board were all chinese garbage ones except for 2 Sam Young caps which was part of the initial replacement, till I replaced the ones I mentioned with Rubycon caps ordered through badcaps.net.

Nick

[nickt1862]

Re: Syncmaster 2253lw inverter "not turning on"

1) The 47uF 50V is probably your startup cap. It helps the SMPS startup properly.

2) If this was my monitor, I would have replaced the first 3 and left the big filter cap as is (100uF 450V).

3) If the backlights are not coming on and you have proper DC voltage to the inverter section, then you could have a blown fuse and/or shorted out mosfets/transistors in the inverter section.

retiredcaps,

Yeah replacing the rest except the 100uf 450v was my plan and it seems is what I'll do first and see what happens. Those remaining 4 are all Chinese branded garbage.

One fuse on mine is a button type 250v, T3, 15AL.
The other by the inverters is a 125v, F4, 0AL

Nick

[Jasgriff]

Re: Syncmaster 2253lw inverter "not turning on"

Are the fuses testing as open?

[nickt1862]

Re: Syncmaster 2253lw inverter "not turning on"

Are the fuses testing as open?

Jasgriff,

I didn't get that far yet.


Nick

[Jasgriff]

Re: Syncmaster 2253lw inverter "not turning on"

Do you have a multimeter and know how to check them?

[nickt1862]

Re: Syncmaster 2253lw inverter "not turning on"

Do you have a multimeter and know how to check them?

Setting the meter to OHMS and a good fuse should read almost zero ohms.

Most people say to take the component out to test and the probes on both leads.

Now I have to work on acquiring a multimeter.

Always wanted to get one, never got around to it or had a good enough reason to get one.

Nick

[nickt1862]

Re: Syncmaster 2253lw inverter "not turning on"

Deleted subpar photos - new ones in next post.

[nickt1862]

Re: Syncmaster 2253lw inverter "not turning on"

Photos of the board.

[Jasgriff]

Re: Syncmaster 2253lw inverter "not turning on"

Multimeter's are not that expensive to buy if you are just doing the basics.

You are right on the fuse testing however you wont need to take out the fuses to test them. Make sure that there is no power going to it whilst your checking.

[nickt1862]

Re: Syncmaster 2253lw inverter "not turning on"

Multimeter's are not that expensive to buy if you are just doing the basics.

You are right on the fuse testing however you wont need to take out the fuses to test them. Make sure that there is no power going to it whilst your checking.

Thanks

[Jasgriff]

Re: Syncmaster 2253lw inverter "not turning on"

And Mr Retiredcaps will more than likely be along shortly to advise you on a good mulitmeter. I am sure there were some good ex military/government meterman ones that he has found before. Not sure if they are still kicking about.

[retiredcaps]

Re: Syncmaster 2253lw inverter "not turning on"

And Mr Retiredcaps will more than likely be along shortly to advise you on a good mulitmeter. I am sure there were some good ex military/government meterman ones that he has found before. Not sure if they are still kicking about.

The 34XR $10 deal is long dead. This was the original deal 2 months ago.

https://www.badcaps.net/forum/showpo...02&postcount=8

@nickt1862, what is your budget for a multimeter?

If you don't mind buying off ebay, this is a decent deal.

$12.47 + free shipping for a Meterman DM9B (I have the predecessor to this one)

http://www.ebay.com/itm/110642474359

The DM9B will certainly be more than adequate for troubleshooting and a good overall tool.

[nickt1862]

Re: Syncmaster 2253lw inverter "not turning on"

The 34XR $10 deal is long dead. This was the original deal 2 months ago.

https://www.badcaps.net/forum/showpo...02&postcount=8

@nickt1862, what is your budget for a multimeter?

If you don't mind buying off ebay, this is a decent deal.

$12.47 + free shipping for a Meterman DM9B (I have the predecessor to this one)

http://www.ebay.com/itm/110642474359

The DM9B will certainly be more than adequate for troubleshooting and a good overall tool.

Thanks sooooo much for trying to help me in acquiring a multimeter.

I may have missed this (because I'm so tired right now lol!) but I don't think this is capable to also measure capacitance.

I'd be willing to spend a tad more to have that additional feature with what the DM9B already can do unless it can do this as well.

Thanks again,
Nick

[budm]

Re: Syncmaster 2253lw inverter "not turning on"

Most DMM's with cap meter function will not be able to read large value capacitance, you should get the real cap meter with ESR function instead.

[retiredcaps]

Re: Syncmaster 2253lw inverter "not turning on"

I may have missed this (because I'm so tired right now lol!) but I don't think this is capable to also measure capacitance.

Measuring capacitance is not as useful as being able to measure ESR (equivalent series resistance). NO multimeter can measure ESR. You need a standalone ESR meter to measure ESR. Unless you will go in the repair business, investing an ESR meter has a long payback period as they start at $65 or more. Replacing caps "blindly" costs a lot less than $65.

If the 34XR $10 deal were still active, the 34XR can measure capacitance up to 4000uF. For your purposes, the DMB9 will work fine.

The Fluke 110 series can measure capacitance up to 10,000uF, but getting one used off ebay will probably cost $75 to $100.

edit: Hmm, second thread where budm is typing faster than I am!

[nickt1862]

Re: Syncmaster 2253lw inverter "not turning on"

Most DMM's with cap meter function will not be able to read large value capacitance, you should get the real cap meter with ESR function instead.

Thanks!

Measuring capacitance is not as useful as being able to measure ESR (equivalent series resistance). NO multimeter can measure ESR. You need a standalone ESR meter to measure ESR. Unless you will go in the repair business, investing an ESR meter has a long payback period as they start at $65 or more. Replacing caps "blindly" costs a lot less than $65.

If the 34XR $10 deal were still active, the 34XR can measure capacitance up to 4000uF. For your purposes, the DMB9 will work fine.

The Fluke 110 series can measure capacitance up to 10,000uF, but getting one used off ebay will probably cost $75 to $100.

edit: Hmm, second thread where budm is typing faster than I am!

Okay then, I shall order the DMB9.

Thanks so very much for educating me on multimeters and such as I've never used one hence the "beginner" type questions on them.



My new "problem" I'm having is finding a place that has good branded low esr 105 degree caps in these values:

2 x 10uf 50v
1 x 47uf 50v
1 x 100uf 16v
1 x 470uf 25v
2 x 1000uf 25v

Newark, Digi-key, MCM Electronics and such seem sell some which have no indication if it's low esr on any of the good brands and I only find the Chinese garbage ones that state low esr 105 degrees.

Nick

[retiredcaps]

Re: Syncmaster 2253lw inverter "not turning on"

I've never used one

See my fellow Canadian's 5 minute tutorial

http://www.youtube.com/watch?v=bF3OyQ3HwfU

2 x 10uf 50v
1 x 47uf 50v
1 x 100uf 16v
1 x 470uf 25v
2 x 1000uf 25v

For each value above, go to digikey.com type the following into the search field.

10uf 50v fr

If no stock, try

10uf 50v fm

If no stock, finally try

10uf 50v fc

FR and FM are the preferred choice. If neither are available choose, FC. All are made by Panasonic and are good quality low ESR caps.