Got on hand a motherboard that has a small polymer cap knocked slightly out of place (still attached). It is just surface mounted (no holes) and due to other components in the area is next to impossible to de-solder using an iron. Would it have any chance to work if I manage to pull back the legs all the way inside?
Sorry if this sounds like a silly question, but I'm not so familiar with the inner workings of the polymer caps.
Adrian_
Member
Last Activity: 07-08-2020, 04:48 AM
Joined: 03-03-2017
Location: Bucharest
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Pulled polymer cap still attached to the MB
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Re: A bit of help with this Delta for HP PSU (DPS-575AB)
Those workstations could be equipped with either one or two CPU's (socket 771) and have separate rails for each CPU plus two more rails (one for RAM, PCI and so on and one for PCI-E plus IDE/SATA) . My guess is that those 5W resistors are offering some load for the two CPU rails.
I was thinking just to extend their leads so there is some space between their base and the secondary PCB. -
Re: A bit of help with this Delta for HP PSU (DPS-575AB)
Thanks guys
The fan appeared to work as intended during the self test, but I will check if it revs up under load as well.
That green cap next to the 5W resistor looks indeed like it had a hard life, I'll see if I have a suitable replacement.
If this PSU wasn't overloaded and those two 5W resistors managed to cook the PCB so well on their own while the unit was working as intended I'd say this is a clear case of design flaw. This PSU was used on a XW6400 workstation that...Leave a comment:
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Re: A bit of help with this Delta for HP PSU (DPS-575AB)
Well, it turned out to be one of those cases where following the "blood trail" is more then enough
After looking at how discolored was the pcb on the back of those 5w resistors I decided it would be a good idea to check the components in that area first. And the most exposed appeared to be those four 0 ohm SMD resistors, probably used as shunts during the automated production. 30 seconds later I have discovered that one of them had departed to a better world, where currents flow unrestricted
....
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Re: A bit of help with this Delta for HP PSU (DPS-575AB)
Yes it does have a green led but it doesn't turn on when plugging the psu to the main with the atx connector disconnected. (as it should) Also the fan isn't spinning at all.
I believe it's the flash making those connections look bad but I'll double check tomorrow and report back
Thanks for the chip info
Last edited by Adrian_; 02-25-2018, 03:20 PM.Leave a comment:
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Re: A bit of help with this Delta for HP PSU (DPS-575AB)
It's not starting at all, despite the primary side looking all good. However if you zoom a bit the photo of the back of the pcb it looks to me like the DNA 1002D chip is fried.
Is there any quick way to test it using a digital multimeter?
Aso what could have caused the 5W resistors to heat up like that? The motherboard seems to be working OK with another PSU.Last edited by Adrian_; 02-25-2018, 12:04 PM.Leave a comment:
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A bit of help with this Delta for HP PSU (DPS-575AB)
Found this fried PSU into a rather nice XW6400 that got donated to charity in non working condition.The primary is good but the damage on the secondary appears rather extended, do you think this can be fixed and if yes how would you go about it?... -
Re: Help me identify this little bugger (schotty diode?)
Could be, I'll check to see if both anodes track to the same front panel pin or something like that...Leave a comment:
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Re: Help me identify this little bugger (schotty diode?)
Thanks for the reply. That's what I thought as well, the problem is identifying the correct type of BAT54. According to my readings it should be a common cathode B54C, the problem being that I identified another on a working motherboard and it also has continuity between the two anodes...Leave a comment:
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Re: Help me identify this little bugger (schotty diode?)
The markings are "KL3" written horizontally and "V1" written vertically. The photo is a bit fuzzy but the damn thing is very small (3-4mm I'd say)Leave a comment:
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Help me identify this little bugger (schotty diode?)
This motherboard does nothing when power button is pressed, and this little bugger appears to be shorted. (0.4ohm between the lower two legs, either way)
Only I cannot find any reference about the exact type. I'm guessing one of these [url]https://cdn.badcaps-static.com/pdfs/aacf8f7a562ff07084f1153a27052316.pdf[/url] but I'm not knowledgeable enough. Could be way off...
Thanks a lot for any help.https://This motherboard does nothin...<br /> <br />... -
Re: Anyone familiar with the Delta DPS-250AB 18A PSU?
Thanks for the advice. The reason why I wanted to somehow identify the rails is that I'm helping a charity fix some old components and put together usable systems (to be subsequently donated and so on). As you can imagine, there's little time for testing and I wanted to make sure the psu isn't going to die soon due to overload if a video card of about 50w is used.Leave a comment:
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Re: Anyone familiar with the Delta DPS-250AB 18A PSU?
Sadly I don't have a load tester. Probably I should get some beefy resistors and try loading the rails, are there any caveats to this approach?Leave a comment:
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Re: Antec NeoHE430 worth buying/recapping?
It turned up to be something wrong with the old mobo I was using for the test. Tried it on another one and all the voltages are rock solid and within spec.Leave a comment:
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Re: Antec NeoHE430 worth buying/recapping?
Just a quick follow up after the package from Behemot arrived (turned out that shipping from the Czech republic to my own country wasn't really expensive):
I removed all the caps that were replaced during the previous recap job done by some idiot. Found the following:
1x Samwa RD 3300uf 10v
2x Samwa RD 2200 uF 10v
1x Daewoo RUS 2200uF 16v
1x Samwa RD 1000uF 6.3v (tiny bugger placed on a huge 10mm cap post)
I went overboard and used 4x 3300uF 16v plus a 3300uF 6.3v instead of the tiny 1000uF...Leave a comment:
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Re: Anyone familiar with the Delta DPS-250AB 18A PSU?
I was going to do just that, but the resistance between the yellow lines on the MB connector and any other yellow line in the system (CPU, SATA, Molex) is under 1 ohm.
Is there any other method to check, except for opening up the PSU?Leave a comment:
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Re: HP Proliant ML110 G5 - CAUTION RISK OF FIRE (epic fail!)
This has to be somehow related with high humidity levels or some contaminants in the air (don't laugh, I've seen once a server kept in a kitchen
).
Probably the contacts corrode due to humidity/contaminants and the increased resistance causes them eventually to catch fire.Leave a comment:
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Re: Anyone familiar with the Delta DPS-250AB 18A PSU?
Hi and thanks for the suggestion.
I already tried to measure the resistance between all yellow lines (and black lines as well). They all read 0.6-0.7 ohm. (Yelow to yellow and black to black, of couse)
I will try to measure voltages under load as well. Of course, it's possible that the PSU has two rails but the weaker one is not connected at all, but to figure that out I'd have to remove it and open it up.Leave a comment:
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Anyone familiar with the Delta DPS-250AB 18A PSU?
Found this in a 2008-2009 mini Atx HP computer and it appears to have a curious two rails design.
On it's label it says "+12V1 = 8A, +12V2 = 14A" The problem here is whether the first +12v rail is only for the main MB connector, while the second one includes the CPU 4pin connector and the MOLEX/SATA connectors
OR
the first rail includes the main MB connector plus the CPU connector while the second rail includes only the MOLEX/SATA connectors?
Second one wouldn't make much sense (the PSU doesn't have a PCI-E power connector) but...Last edited by Adrian_; 12-06-2017, 10:24 AM. -
Re: Thoughts on this ESR meter
I've been doing it for a long time , but was looking for something that could do in-circuit discharges without involving pliers, in case the distance between the contacts is wider then the screwdriver's head . Not to mention high voltage caps, even if I suspect that no El Cheapo cap/ESR meter can safely discharge those......
Last edited by Adrian_; 11-29-2017, 04:05 PM.Leave a comment:
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