Matsui M32LW409 no picture but sound

[tom66]

Re: Matsui M32LW409 no picture but sound

There is a reason the engineers put two capacitors on there. Omitting one may work, but it could cause further issues down the line. The stability of the dc-dc converter could be affected adversely.

[Th3_uN1Qu3]

Re: Matsui M32LW409 no picture but sound

They are local decoupling capacitors. It is common practice to put them, they are not 100% required. When repairing cellphones there are often problems caused by shorted capacitors. Trust me, nobody bothers to replace those little buggers. The offending cap is simply scraped off with a blade and the phone goes back to the customer.

Replacing these capacitors is recommended but not mandatory. And you can use anything that fits in their place. They are not critical like on a power supply or VRM.

[tom66]

Re: Matsui M32LW409 no picture but sound

I do power supply testing at work. Usually using MLCCs. It's easily possible missing that capacitor could adversely affect the stability of the converter. They are not decoupling capacitors. They are the input capacitors for a boost converter (AVDD, 15V @ 1.5A.)

It is OK for a quick test, but running continuously could cause a problem in the future.

[Th3_uN1Qu3]

Re: Matsui M32LW409 no picture but sound

I wasn't saying he should leave the set running that way if it works. But it definitely can be tested like that, to check if it's good, or there are more issues.

[Andyd1970]

Re: Matsui M32LW409 no picture but sound

Hi Guys,

I tested the Caps with a meter CP1 it was O/C CP3 was short circuit with the meter on ohms. I replaced CP1 but still got the same no picture but sound, FP1 is O/C.

I would like to replace the fuse and CP3 where do I find them on ebay? what value is the fuse and CP3?

Thanks for all your help guys.

[Th3_uN1Qu3]

Re: Matsui M32LW409 no picture but sound

CP3 can be pulled from dead laptop boards or similar, check the ones near the input dc jack or near the battery connector. Any of those will work. For the exact value you can use a capacitance meter. As a guess, it should be 10uF 25v or 22uF 25v.

For that type of fuse, the fuse's rating is printed on it as a code. The code "UD" solves to 3.15A. See here: https://cdn.badcaps-static.com/pdfs/...7263e74802.pdf. It seems to be SMD 0603 size.

[Andyd1970]

Re: Matsui M32LW409 no picture but sound

Thank you,

But where do I get those surface mount fuses? and what rating?

[tom66]

Re: Matsui M32LW409 no picture but sound

Do you not have a capacitance meter available, or a capacitance range on your multimeter?

[Th3_uN1Qu3]

Re: Matsui M32LW409 no picture but sound

But where do I get those surface mount fuses? and what rating?

I have already mentioned, the rating of the original fuse is 3.15A. You can find them at any reputable supplier, like Farnell, Digikey and so on. You can also try ebay.

[tom66]

Re: Matsui M32LW409 no picture but sound

CPC sell packs of 10 for about £3 inc VAT. Min order £5 via card, free delivery, so throw a reel of Chemtronics solder wick on there (£2.50 inc VAT.)

[Andyd1970]

Re: Matsui M32LW409 no picture but sound

Hi Guys, I have just used my meter which has a setting for capacitors and it indicated 23.3uf. So do I go for 23uf or 24uf?

[Th3_uN1Qu3]

Re: Matsui M32LW409 no picture but sound

22uF is the standard size and that is what you should order. Some may measure higher or lower, generally higher. Regular capacitor tolerance is -20%/+80%.

[Andyd1970]

Re: Matsui M32LW409 no picture but sound

Sorry to be a pain but just spoke to CPC who said they do not do the fuses would you be kind enough to send me the item number/link so I can order them, also the same with the caps as they said they have soo many to offer.

Thank you in advance.

Andy

[tom66]

Re: Matsui M32LW409 no picture but sound

Fuses
http://cpc.farnell.com/multicomp/mc0...-3a/dp/FF02260

[Th3_uN1Qu3]

Re: Matsui M32LW409 no picture but sound

The original fuse is 3.15A. A 3 amp fuse might blow for no reason after a number of power cycles. Sure, it's not that big of a difference, but it's better not having to pull the set apart again.

[tom66]

Re: Matsui M32LW409 no picture but sound

It's being pedantic. Fuse failure rate is proportional to the square of the current. If you wish, they stock 4A fuses... it's generally bad practice to increase a fuse rating but I don't see harm being a likely outcome in this case.

[Andyd1970]

Re: Matsui M32LW409 no picture but sound

Thank you so much guys for all your help, sorry to be a pain but can you send link to the correct capacitor as they asked all kinds of questions about the spec I needed.

Thank you

[Andyd1970]

Re: Matsui M32LW409 no picture but sound

Hi Guys,

Order the 4amp fuse better to be safe than it blow again

Capacitors I ordered the following, hope that are OK? I take it I should fit the 35v one and not the 16v one??

http://cpc.farnell.com/kemet/b45196e...-bb45-00001003

http://cpc.farnell.com/kemet/b45196h...-bb45-00001003

If you could confirm that would be great and I will let you know once they arrive and I fit them.

Thank you

[tom66]

Re: Matsui M32LW409 no picture but sound

They are tantalums. They will work but you will need to be absolutely sure to get the polarity correct (if wrong they will usually violently burn.) You may need to bend the leads to meet the pads.

[Andyd1970]

Re: Matsui M32LW409 no picture but sound

Hi Tom,

Glad I posted that, or can you recommend a more appropriate capacitor from CPC ASAP so I can add to my order? Or how will I tell which way to fit them and which pad on the TCON is the positive or negative.

Help