Stumped this weird G4 power supply problem

[JOHNBOY]

Re: Stumped this weird G4 power supply problem

All day today I was dreaming that I can come back here and thank toasty and everything would work. But I changed the final caps today and it still doesn't turn on.

I replaced something like 17 out of 18 caps with all new ones, the only one I didn't change is under the fan control and looks like a small 0.47uf or similar.

When I plug it in I get 5v on one probe and 24v on the other but trying to turn it on by jumping it only makes the fans spin for one second and nothing happens. The 5v and 24v remain put none of the other leads only turn on for 1 second.

[Toasty]

Re: Stumped this weird G4 power supply problem

What brand & series caps did you re-cap with? Sounds like the WT7515 OC/OV IC is shutting it down for some reason. Again, loading the supply with mobo and drives may have a role here.

[JOHNBOY]

Re: Stumped this weird G4 power supply problem

It gives a worse result in the system. The shorting method is the only thing I can do get the fans to spin up for a second or two. If I can keep it going for 3 seconds I will hear that clicking sound about 10 times. a tiny little click somewhere near the power cord side of the board.

I don't know what caps I used. I had to go to several stores to get the right sizes. They are your standard cheapos from sayal and active electronics.

The ones I didn't change were the 2700uf 6.3v because I couldn't find one but the one I reused was charging and discharging fine with a voltmeter. And 1-2 tiny ones on the north side of the board by the 2nd heatsink. I don't think those two are responsible for starting it.

[Toasty]

Re: Stumped this weird G4 power supply problem

Then the problem is that you used caps that are "standard grade" in a power supply that *requires* low ESR types. Unfortunately, you have wasted time and effort by doing so. Read the site FAQ's under "Battling the Bad Capacitors".

What brand/series caps did you get from badcaps.net? (Posts #10-11)

On the matter of that 2700uF cap - Testing with a VOM does *not* indicate that the cap is good. It simply means that it is not shorted or open (at this moment) and is reacting as most any electrolytic cap would. It has no bearing on its' capacitance or ESR values.

Toast

[Ed in SoDak]

Re: Stumped this weird G4 power supply problem

I'm pretty new at this game myself, but an old car mechanic's trick might help track the clicking sound. Just use a length of plastic tubing, put one end in your ear, and probe around with the other end for the sound.

-Ed

[JOHNBOY]

Re: Stumped this weird G4 power supply problem

Then the problem is that you used caps that are "standard grade" in a power supply that *requires* low ESR types. Unfortunately, you have wasted time and effort by doing so. Read the site FAQ's under "Battling the Bad Capacitors".

What brand/series caps did you get from badcaps.net? (Posts #10-11)

On the matter of that 2700uF cap - Testing with a VOM does *not* indicate that the cap is good. It simply means that it is not shorted or open (at this moment) and is reacting as most any electrolytic cap would. It has no bearing on its' capacitance or ESR values.

Toast

A couple of them did say low ESR.. I didn't get any caps from here. It took me two weeks to get a hold of that guy and when I sent him the list he never replied.

So if I replace it with low ESR you think it will make a diff ? I somehow doubt it because with the original caps in there I got the same clicking noise. I figuered this would be some other component.

I have another 2700uf in a system. I'll try that one to see if anything changes.

It sounds to me like the clicking is coming from a 10 pin or so IC

[ratdude747]

Re: Stumped this weird G4 power supply problem

if it said low esr, then it was probably crap caps... the good ones do not say low esr on them. crap ones are a waste of time... no wonder your unit does not work.

get good ones next time, and not from ebay or local electronics shop. buy them here at badcaps, didgikey, or mouser.

i recommend buying them here... tc does good business...

and if you do not buy from here, post what brand/series they are before you order... stick to these brands:

rubycon
panasonic
nippon chemicon
united chemicon
sanyo/suncon
samxon
nichicon

[JOHNBOY]

Re: Stumped this weird G4 power supply problem

I tried to buy them from here but the guy never replied. I'm not so sure this is the caps. I think it might be some other component.

[ratdude747]

Re: Stumped this weird G4 power supply problem

he was busy and on vacation last month.

i bet you dimes to doughnuts it's the caps... the caps you bought were bad, so the result is bad.

try topcat again... if he still does not reply, post about it... he should.

[PCBONEZ]

Re: Stumped this weird G4 power supply problem

dimes to doughnuts ????

[ratdude747]

Re: Stumped this weird G4 power supply problem

it's a term my family uses a lot... means pretty sure...

[midibob]

Re: Stumped this weird G4 power supply problem

I wouldn't ignore those 0.47uF either. If one of them is near a heatsink it's possible it could be part of the oscillator section and dried up. I don't know the model so I couldn't say for sure.

I know this is easy to say if you've got the kit but in cases like this you really do need to measure the caps with an ESR meter just to be sure.

I would also add that swapping out all those new caps for 'known' low ESR types still might not cure your problem so be prepared to be disappointed.

Good luck
Midibob

[JOHNBOY]

Re: Stumped this weird G4 power supply problem

So I suspect what is happening is I turn it on and there is an overload of some type and it shut downs.

I did find the names of some of my caps

The tiny ones are Rubycon

I have a couple with a capital A in a box as the logo, don't know what that brand is

I brand called 'forever'

And one says (M)CEHFQ

[ratdude747]

Re: Stumped this weird G4 power supply problem

rubycon is good, the rest are complete s***. get good ones next time.

[JOHNBOY]

Re: Stumped this weird G4 power supply problem

So is a ESR rating of 18 or 20 good

[ratdude747]

Re: Stumped this weird G4 power supply problem

hell no... much lower than that.

[370forlife]

Re: Stumped this weird G4 power supply problem

18-20 is wayyyyyyyyyyyyyyyyyyyy to high, but did you measure them in circuit or out of circuit?

[JOHNBOY]

Re: Stumped this weird G4 power supply problem

I didn't measure anything. I'm looking at web sites to order from and they list the ESR rating.

[JOHNBOY]

Re: Stumped this weird G4 power supply problem

Is the rubycon ZL series any good ?


Capacitor Dielectric Type: Aluminum Electrolytic Capacitance: 2200uF Capacitance Tolerance: ± 20% Voltage Rating: 6.3V ESR: 0.02ohm Series: ZL

[370forlife]

Re: Stumped this weird G4 power supply problem

ZL is good.