Did I do anything wrong?

[epixie]

So I had this problematic HP Touchsmart 300 "all-in-one" computer sent to me. It would run for a few minutes, and then cut power off. Oddly enough, the LED on the power button would stay lit, but system goes on a complete dead stop. I checked the motherboard and everything (overheating and the like), and it looks fine. So that leaves the power supply...

Since this unit uses a propietary Delta DPS-200PP-171(a) power supply, it leaves my usable spare ATX power supplies out of the question for troubleshooting.

Previously, I successfully recapped a Dell E153FPc with some UCC caps salvaged from another board - prior to that, the monitor would stay on for a few minutes and then shut off whilst the power button LED stayed lit. So I guessed it must be the same problem.

Off to Digikey, I purchased some Nichicon caps:

RATING QTY L X D NOTES PICK

16v, 1000uf 3 ea 20X10MM UPW1C102MPD x
10v, 1000uf 1 ea 20X8MM UPW1A102MPD6 x
50v, 10uf 2 ea 8X5MM UPW1H100MDD x
50v, 47uf 1 ea 11x7mm (guess) UPS1H470MED x
50v, 100uf 1 ea 10x8mm (guess) UPW1H101MPD

450v, 150uf 1 ea 30x25mm P11804-ND x

After soldering, I tried to boot up the system, the fans would spin but the LCD will not come on. Also, I checked the red (5v) wires show 0 volts on the multimeter but the 12v rail still has 12v present on it. If someone here has the schematics for the DPS-200PP-171, I'd like to have one; as well as your input.


When I get back from my regular day job, I'll try to post some pics of this baby.
Thanks!

[sam_sam_sam]

Re: Did I do anything wrong?

Did you recap the power supply ?

Also check and make sure that you did not put any cap in backwards

[sam_sam_sam]

Re: Did I do anything wrong?

When I get back from my regular day job, I'll try to post some pics of this baby.
Thanks!

Please Do this this will help

[epixie]

Re: Did I do anything wrong?

I hate proprietary power connectors.

Ugh.

[selldoor]

Re: Did I do anything wrong?

Check all your joints with a magnifying glass also as the original problem could have been due to a bad joint check the whole boards. Pic...6007
a few of the joints dont look great but that may just be the picture.?

[epixie]

Re: Did I do anything wrong?

Check all your joints with a magnifying glass also as the original problem could have been due to a bad joint check the whole boards. Pic...6007
a few of the joints dont look great but that may just be the picture.?

RoHS lead-free solder.

My Pace MBT-200 has had a hard time melting the through-hole joints. I've got it set in the max setting but it wouldn't budge. I've checked the board for any cracks, but I can't really see anything that would indicate otherwise.

[sam_sam_sam]

Re: Did I do anything wrong?

Frist thank you for the photos

My Pace MBT-200 has had a hard time melting the through-hole joints. I've got it set in the max setting but it wouldn't budge. otherwise.

Here is a trick you can try put lead based soldier on the joint then suck all of away then reapply the soldier this works for me about 99%of the time

from the photo the big main board there look to be some ? able joints

What are the brand names on these caps that are on this board

[epixie]

Re: Did I do anything wrong?

Frist thank you for the photos




Here is a trick you can try put lead based soldier on the joint then suck all of away then reapply the soldier this works for me about 99%of the time

from the photo the big main board there look to be some ? able joints

What are the brand names on these caps that are on this board

Done that, including tinning the desoldering tip with 60/40 solder. It sort of worked, but not as fast as running my Hakko 936 at 405*C and a Soldapullt on the hole. Hmm, weird

The replacement caps are all Nichicon PW series as well as one PS cap (UPS1H470MED). I wonder if my selection of replacement caps has something to do with it.

[SeanB]

Re: Did I do anything wrong?

Tried reflowing those diodes on the secondary side. Some look like they are suspect, which would cause a dropped supply rail. Also on the control board some of the through hole parts at the bottom by the connector look dry jointed.

[epixie]

Re: Did I do anything wrong?

EDIT: Got it to work...sort of. Let's see what'll happen in the next 24 hours.
EDIT: Worked, but still shuts off at random intervals. Hmmmm....

[sam_sam_sam]

Re: Did I do anything wrong?

Tried reflowing those diodes on the secondary side. Some look like they are suspect, which would cause a dropped supply rail. Also on the control board some of the through hole parts at the bottom by the connector look dry jointed.

I would add this as well any joint look like it has a lot of flux I would redo those joint as well

[ben7]

Re: Did I do anything wrong?

Done that, including tinning the desoldering tip with 60/40 solder. It sort of worked, but not as fast as running my Hakko 936 at 405*C and a Soldapullt on the hole. Hmm, weird

The replacement caps are all Nichicon PW series as well as one PS cap (UPS1H470MED). I wonder if my selection of replacement caps has something to do with it.

Hint Hint... I've had success with adding extra flux, that tends to help those stupid lead-free joints melt.

Do you know exactly what happens when it shuts off? Like, do the main rails go down, or does the standby go down too?

I'm thinking it is probably a bad solder joint. Or something could be wrong with the motherboard.

[epixie]

Re: Did I do anything wrong?

Hint Hint... I've had success with adding extra flux, that tends to help those stupid lead-free joints melt.

Do you know exactly what happens when it shuts off? Like, do the main rails go down, or does the standby go down too?

I'm thinking it is probably a bad solder joint. Or something could be wrong with the motherboard.

It goes into an unrecoverable 'standby' mode where the power button LED is still lit, but everything else is powered down. So it means the mainboard is still powered, but it has entered a powered-down state that it couldn't get out. Holding the power button long enough won't turn the unit off, I have to physically unplug it. I've seen it happen in the Dell monitor I recapped several months ago -- semi-bulged CapXon caps.

I've checked the HP motherboard and everything looks like fine (physically) for now, as I do not have access to an ESR meter. The HP motherboard has brown United Chemicon caps on it, I think. The rest are surface mount radial caps.

Now here's the weirder twist of things: I've consistently powered up and down the unit, and every time it would go off, the amount of time it would stay 'turned on' when I re-powered it, would be decreased.

Other than that, I catched an Ltec(!) cap covered in heat-shrink tubing while I was desoldering the SMPS daughterboard off - the one that has the Fairchild KA7500c chip on it.

More later. Insights welcomed.

[goontron]

Re: Did I do anything wrong?

replace it. i have had a Macintosh plus refuse to shut down because of a dry cap on the daughter board for the PSU.

[epixie]

Re: Did I do anything wrong?

replace it. i have had a Macintosh plus refuse to shut down because of a dry cap on the daughter board for the PSU.

The Ltec cap?

[goontron]

Re: Did I do anything wrong?

The Ltec cap?

yer. 25uF 50v, it was at 5uF

[epixie]

Re: Did I do anything wrong?

UPDATE: Now waiting for the shipment from Mouser. We'll see what'll happen next.

Part number is UPS1H220MDD.

[Khron]

Re: Did I do anything wrong?

What series are the Chemicon caps on the motherboard?

I've read around here that KZG/KZJ don't really like heat, and are prone to failure without bulging / venting / leaking.

[epixie]

Re: Did I do anything wrong?

What series are the Chemicon caps on the motherboard?

I've read around here that KZG/KZJ don't really like heat, and are prone to failure without bulging / venting / leaking.

I'm busy with other things right now, and short of money

The mainboard has two large radial KZG caps and some smaller Lelons (the small 5x8mm ones, I think). Once I have an ESR meter, I'll try to take a look on them.

[epixie]

Re: Did I do anything wrong?

UPDATE:

Replaced ALL electrolytic caps on the power supply with Nichicon PS and PW caps; still has the random shutdown. Fires right up, boots all the way to Windows...and suddenly cuts off. Oddly enough, the WLAN module still keeps on blinking.

Odd, very odd.
Can someone give their insights?