Repaired laptop charger , is it safe to use ? - General query

[jarvis7]

Hello , couldn't find a main sticky topic to ask simple queries so creating a thread...

I had a standard 20v 2.25A lenovo laptop charger with square tip and Lenovo b40-70 laptop .. it wasn't charging the laptop , as soon as i plugged in, laptop charging led would glow for some milliseconds and then switch off .. so i took it to a local tv repairmen .and when checked with multi meter the needle was flickering , he checked it with a bulb and it was flickering ... he opened it up and there was electrolyte leakage .. so capacitor was blown up .. and told me capacitor needs to be replaced

The first time he changed the capacitor , it was able to charge the laptop only when not powered on .. as soon as i powered on the laptop the charging led would switch off automatically and it wasn't taking the charge , he checked it again with the bulb and the bulb didn't power on .. but once the charger was switched off/on again it would power on the bulb and start charging as long as i didn't turn the laptop on .. and the cycle continued

so he changed the capacitor again saying this time he used a higher capacity capacitor .. and this time the charger was able to charge laptop perfectly even when laptop is powered on ..

now the question i have is.. is it safe to use this charger to charge laptop or should i change it..i am sure he must have used a cheap capacitor , can it kill the laptop motherboard ? with a high ripple or something ? or does the laptop and charger have safety features builtin to not accept the charge when it is dangerous or something ? and can i use this charger without worrying ?

i tried posting pics , opened it up but it is jammed in metal plate and couldn't get a decent shot where capacitor values could be seen

Thanks for reading ..

[goontron]

Re: Repaired laptop charger , is it safe to use ? - General query

I'm going to make an ass out of myself here, and assume the square plug chargers use the same logic as the round plugs. In which case, if the PSU is crashing like that the one-wire control circuit won't be running in the charger, therefor it wont charge. As for whether it will damage anything.... IDK.

[jarvis7]

Re: Repaired laptop charger , is it safe to use ? - General query

Thanks sir for replying ... i have attached internal images of Charger ...

i could only see 3 capacitors ..

big one - 450v , 82Uf brand unknown
left side blue one - 1000uf , 25v G-Luxon
tiny green one - 22uf , 50v Taicon ( on top left side of big one, where 450v is written )

can somebody please tell me now if it is safe to use and will not harm motherboard/other components ?

--- it is working fine and able to charge the laptop

thanks

[goontron]

Re: Repaired laptop charger , is it safe to use ? - General query

That small green one may be critical, and is a Crapacitor . If it failed, it could blow up the charger. The large one is a Chemi-con. Good brand. The blue G-Luxon is not OK for use here. They do not do well with how hot these charges get....

[Th3_uN1Qu3]

Re: Repaired laptop charger , is it safe to use ? - General query

A repaired genuine charger will be safer to use than a knockoff replacement. My 2 cents.

[jarvis7]

Re: Repaired laptop charger , is it safe to use ? - General query

That small green one may be critical, and is a Crapacitor . If it failed, it could blow up the charger. The large one is a Chemi-con. Good brand. The blue G-Luxon is not OK for use here. They do not do well with how hot these charges get....

Thank you sir but isn't Taicon like the best non-japanese capacitor brand out there ?

and as long as G-luxon cap works , can i trust that it isn't going to harm motherboard/other parts through high ripple or voltage ?

Thanks

A repaired genuine charger will be safer to use than a knockoff replacement. My 2 cents.

thank you sir , yes this is what i am concerned about and hesitating to buy a cheaper knock off replacement ..

[Th3_uN1Qu3]

Re: Repaired laptop charger , is it safe to use ? - General query

That capacitor is not going to harm anything, but if it goes bad, charger will stop working again. Genuine chargers have protection circuits built-in which will prevent them from doing damage to the board.

[momaka]

Re: Repaired laptop charger , is it safe to use ? - General query

A repaired genuine charger will be safer to use than a knockoff replacement. My 2 cents.

Make that 4 cents now

I'll take a repaired genuine charger over a cheap replacement any day.

That said, if that TV repair guy is using crappy caps for repairs, I would avoid him in the future, unless you really have no one else to go to. I hate it when people use the cheapest caps available for a *permanent* repair. I use crap caps too sometimes, buy only to verify function. After that, it is Japanese quality caps or waiting on my parts shelf in pieces until I get caps.

As far as this charger damaging your laptop - that is very unlikely to happen. Like Unique said, most are designed well and will shut down when they detect they are not outputting the right voltage or being overloaded. Cheap chargers are not so good with that, so that's why it's better to avoid them.

[jarvis7]

Re: Repaired laptop charger , is it safe to use ? - General query

Thank you very very much the Unique and Momaka sir for clearing that up ..

from what little i read .. i was worried if the capacitor used is of right specs or not , and while it is giving correct output voltage , it might be outputting a higher ripple ..

now i can use this charger without worrying ..

really thanks a lot..

[jarvis7]

Re: Repaired laptop charger , is it safe to use ? - General query

hello everyone i am thinking of getting this cap replaced .. today laptop didn't start charging as i switched on power supply , i reinserted charging pin and it didn't start .. i switched the sides of charging pin ( since square pin can be inserted both ways ) .. it started charging and i reversed the position it again started charging .. i was suspecting bad cap .. so then pulled out the battery .. and plugged it in , then powered on laptop , a few seconds later laptop switched off ..

i switched off and on again power supply from main plug .. it started charging normally ..
now my charging pin is physically loose .. so it could have happened because of that .. but even intentionally when i try hard to make the contact loose , it doesn't loose the charging or the charging led doesn't switch off.. so i suspect it is of bad cap.. anyways i would like to replace it.. though it is working fine now

phyically gluxon looks fine to my untrained eye but i have read gluxon/teapo fail without visible signs..

from what i can see On G luxon cap - it is mentioned GR 85c 906X (M ) 1000uf 25v

i am guessing this is general purpose ? and PSU should use low ESR ?

i'll go to a PC repair shop and ask specifically for a japanese brand cap , ( will avoid KZG /KZJ ).. i have doubts i will get an original cap but let's see .. since fakes are probably sold more than original here

what should be the idle uf and v for the cap ?

and should i also get the tiny Taicon replaced ? or should i leave it since it is considered best non-Japanese brand here from what i have read ?

hard to read but it says -- C1423(M) 105c (PW) P

thanks a lot

[stj]

Re: Repaired laptop charger , is it safe to use ? - General query

pw is wrong.

it's not just brand but series,
it must be a LOW-ESR type capacitor

[Quaddro]

Re: Repaired laptop charger , is it safe to use ? - General query

1st, always use the original capacitance.
It has effect for the ripple.

And always use a brand new low esr japan cap(s) for replacement for permanent fix.
Not the used one.

Do you know the original capacitance of capacitor that the tv repairman had change it?

[jarvis7]

Re: Repaired laptop charger , is it safe to use ? - General query

Thank you Stj and Quaddro Sir

No sir unfortunately i don't have capacitance value of original caps..

can you or somebody else recommend good value long duration caps ? if possible a few alternatives as well

only this site seems good in india that i am aware of.. though high shipping costs .. i hope i get only originals from here..

http://in.element14.com/

i'll buy the caps and then take it repairmen to get them replaced .. is there any way to make sure they are genuine and have all the right specs and will have very low ripple ? thanks

[momaka]

Re: Repaired laptop charger , is it safe to use ? - General query

can you or somebody else recommend good value long duration caps ? if possible a few alternatives as well

All of these are suitable for PSU use, though they are not all exactly equivalent:
Nichicon (PW, PS, PM, PJ, HE, HW)
Rubycon (YXJ, YXG, YXF, ZL, ZLH, ZLJ)
Panasonic (FC, FK, FR, FM, FS)
United Chemicon (LXV, LXZ, KY, KYB, KZE)

For example, there is a big difference between Panasonic FC and FR/FM in terms of ESR and ripple current. However, for a laptop power adapter like yours, it probably has flyback topology, so any of the above should be okay.

only this site seems good in india that i am aware of.. though high shipping costs .. i hope i get only originals from here..

http://in.element14.com/

Element14 has good genuine caps, IIRC. See if you can find any of the above brands and series.

You may also find Suncon capacitors (formerly known as Sanyo). They are probably okay too.

i'll buy the caps and then take it repairmen to get them replaced .. is there any way to make sure they are genuine and have all the right specs and will have very low ripple ? thanks

Should be genuine if you order from Element14. But if you are suspicious, you could always take pictures of your new caps and post them here. Unless you get really good counterfeits, most of the time we should be able to tell.

[jarvis7]

Re: Repaired laptop charger , is it safe to use ? - General query

Thanks once again Momaka sir for all your help

i have selected these 2 .. so do you think 1000uf 25v would be fine for this ? since these values aren't original as they were replaced by repairmen ? and also the 50v 22uf Rubycon YXJ series doesn't mention Low Impedance in main headline in datasheet.. i hope it's ok

please have a look

http://in.element14.com/rubycon/25zl...rad/dp/8126437

http://in.element14.com/rubycon/50yx...rad/dp/2346268

going with Rubycon because of K style vent so maybe slightly harder to counterfit/easy to spot if it's not genuine ( lol.. just guessing )


Thanks

[jarvis7]

Re: Repaired laptop charger , is it safe to use ? - General query

more pics

[momaka]

Re: Repaired laptop charger , is it safe to use ? - General query

i have selected these 2 .. so do you think 1000uf 25v would be fine for this ? since these values aren't original as they were replaced by repairmen ?

1000 uF is okay (more or less) for a charger. If you can fit a higher capacitance cap, then go for it. If not, 1000 uF should be fine.

Rubycon ZLH is good choice for power adapters on flyback topology due to higher ripple current. So you're good there.

and also the 50v 22uf Rubycon YXJ series doesn't mention Low Impedance in main headline in datasheet.. i hope it's ok

Rubycon YXJ is low ESR series of capacitor. The datasheet just says "low impedance" though, and that's because at high frequency, especially around 100 KHz and above, the ESR becomes almost equal to the impedance.

So that YXJ will do just fine. If anything, YXJ is actually made with power supplies and hot environments in mind, so that series has a pretty good endurance rating (5000 hours @ 105C for 5 mm diameter caps rated above 16V).

going with Rubycon because of K style vent so maybe slightly harder to counterfit/easy to spot if it's not genuine ( lol.. just guessing )

Well, you shouldn't be getting counterfeits/fakes from Element14.
That said, the Chinese can fake just about any cap out there, so it doesn't really matter.

If anything, one of the first well-known fake/look-alike capacitors was Rulycon, with the same text and looks like the real Rubycons. And boy were they terrible.

[jarvis7]

Re: Repaired laptop charger , is it safe to use ? - General query

Thankssss a lot Sir

[jarvis7]

Re: Repaired laptop charger , is it safe to use ? - General query

hello sir , this got a bit delayed... have a question before i place an order

my existing g luxon cap is 10 x20mm .. with hardly any extra space for diameter or height

in 1000uf 25v rubycon ZLJ i am getting 20x10mm .. in 1200 uf i am getting 10x25mm

now if i go with 1200 uf 25mm height then the cap height will be too much and top cover wouldn't fit properly .. i can duct tape it with protruding cover adjusting it somehow and managing it with protruding cover .. But is it worth it .. is 1000uf going to be detrimental to ripple and harmful for motherboard ? this is for a 15w tdp pentium 3558u laptop

additionaly there is Panasonic FS in 10x20 1200uf .. but this is new series if i am not wrong and untested and i would like to stick to Rubycon and panasonic costs more

what should i do , thanks a lot..

[NeedsMoreFlux]

Re: Repaired laptop charger , is it safe to use ? - General query

now my charging pin is physically loose .. so it could have happened because of that .. but even intentionally when i try hard to make the contact loose , it doesn't loose the charging or the charging led doesn't switch off.. so i suspect it is of bad cap.. anyways i would like to replace it.. though it is working fine now


My money says the cause was a bad connection this whole time.

Many, many times I have had continuity of 0ohms. yet it was barely making contact and therefore could not pass much current.

I had this happen on a laptop charger that failed because the wire was bad right were it came out of the charger.

Another laptop had a loose VCC(broken solder joints). I assume you know what VCC means? (where the charger plugs into the laptop)