Chieftec HPC-340-201 Rev C0 ATX12V

[JEWilson]

Hi

Have tested it with two types of PSU tester (FWIW).

The first PSU tester does not report any problems.
The second, similarly so.

What are the views of forum members - are these any good?

[999999999]

Re: Chieftec HPC-340-201 Rev C0 ATX12V

First, as others have stated in past threads, I would abandon the PSU testers and develop your own plan for a load test. Cause at least a couple amps of drain on 3.3V/5V/12V rails, and ideally at least 1A on 5VSB rails (though subject to context, some early ATX PSU didn't even claim able to provide 1A on 5VSB so maybe 500mA is a safer target).

If you wire that up to an ATX connector, you can then use the multimeter to get a more definitive answer to pass/fail based on voltage readings, but more importantly, that is done while knowing the load. The primary problem with most small testers is they don't have the size or construction budget to put enough load on all rails, they're just cheap devices with limited usefulness.

As for HPC-340, it's a Sirtec built unit related to HPC-360. I had one that came in an Enlight case, I'll recount it's history. It blew the 5V or 3.3V output cap due to it being not just close but actually cemented to the adjacent load resistor. It had been running for about 18 months at that point, and it wouldn't have surprised me if that cap might have ended up failing regardless of the load resistor, just running longer until it happened.

After that repair it ran for another 24 months or so, with fairly high 5V rail load (overclocked Athlon XP system w/o'c Geforce 3 card used by my nephew for gaming), then blew out a chopper transistor (probably due to a voltage surge on the mains AC, it was redeployed into an environment known to have bad AC power). I was fairly happy it lasted in that use besides blowing the transistor, had wondered if a > 340W PSU was a better match for the system I'd place it in, but it was a free/gift build for someone and I used what spare parts I had at the time.

After replacing the chopper transistor, it was load tested and installed into a testbed system for various non-continuous uses. It sits there today and ironically enough I had pulled that system out to test some flaky HDDs a couple days ago so it happens to sit a foot away from me right now.

Overall, the unit is most susceptible to cap failure in 5V and 5VSB output. Otherwise it is a medium quality unit typical for the era. Upon replacing those caps you might find it has acceptible life powering a modestly endowed older generation system using 5V power for VRM-CPU supply circuit, not a system using 12V for VRM-CPU.

It seems pretty optimistic of me to say it has acceptible life, but given they were often coming free with cases and in that were a great value after replacing a couple parts years later, I'll say that you could do a lot worse for nearly-free but after one has a couple years runtime on it, it may be time to replace some caps before redeploying it.

[JEWilson]

Re: Chieftec HPC-340-201 Rev C0 ATX12V

Thans very much for the detailed response

Although I haven't opened this PSU up yet as it reports no problems, I do have a problem with another Chieftec. I have referred to same in this forum, so far as +5VSB is reported as problematic at least by, profuse excuses extended, a PSU tester.

See further https://www.badcaps.net/forum/showthread.php?t=4461

I concur with the observation the 5V rail cap being glued to the
load resistor - same issue with the problematic Chiefy!
Suggestion, as a possible answer to the siting problem, Would rerouting
the cap placement away from the load resistor as opposed to gluing
it - solve the issue?

If lead length kept to minimun and insulated - is it really worth the effort
considering low end use as suggested? As the cap and the load res are very close to the exhuast fan, making sure it is not joined to the load and mounted well, may be enough.

Thanks for this

[999999999]

Re: Chieftec HPC-340-201 Rev C0 ATX12V

Thans very much for the detailed response

Although I haven't opened this PSU up yet as it reports no problems, I do have a problem with another Chieftec. I have referred to same in this forum, so far as +5VSB is reported as problematic at least by, profuse excuses extended, a PSU tester.

See further https://www.badcaps.net/forum/showthread.php?t=4461

My general policy is that if a system exhibits a PSU related problem and the PSU is pulled and opened, I'll go ahead and replace any caps in question. This is within the context of having maintained a stock of a few popular cap values so I'm not paying an extra $6 to ship a few bucks worth of caps every time, nor having to shelf it then come back to it later.

I concur with the observation the 5V rail cap being glued to the load resistor - same issue with the problematic Chiefy! Suggestion, as a possible answer to the siting problem, Would rerouting the cap placement away from the load resistor as opposed to gluing it - solve the issue?

I know that after I fixed the one I had, it didn't fail again but I don't recall exactly what I did... probably just took an X-acto knife and sliced through the glue as close to the cap as possible, leaving it on the load resistor as a sort of bumper to keep it a certain distance from the cap, then after replacing the cap I just made sure the resistor was still the tiniest bit away from it, but that's not much of an issue as after you have cut the glue it can't make very good thermal contact anymore with the new cap. I'm fairly confident I did not try to relocate the cap or resistor to another spot on the PCB, that the resistor just wasn't re-glued to the cap and was bent slightly away from it. I might've also put a piece of heatshrink tubing over it, I don't recall on that unit but I have on some other PSU.

One other thing I did which is a bit harder to explain. See the rear intake vent slits? Using sturdy needle-noise pliers, at the top and bottom of each slit I twisted the partitioning metal strips to a 90' angle to how they started, which increase the air intake area. I don't recall particulars on that unit but on some if there are parts very close to those slits you would twist the adjacent metal less to be sure it doesn't touch the parts.

If lead length kept to minimun and insulated - is it really worth the effort considering low end use as suggested? As the cap and the load res are very close to the exhuast fan, making sure it is not joined to the load and mounted well, may be enough.

I'm not sure I understand what you mean about "lead length kept to a minimum and insulated". The load resistor has no lead length issues it can be placed anywhere so long as the PCB trace it is soldered to is fairly thick since the resistor will conduct heat to that trace which on some PSU does cause delamination of the trace from the board. The cap on the other hand should remain close to the same spot in the circuit for low impedance to the output wiring hardness and it's leads should be short, it should stay right up against the PCB. The real factor of insulation isn't very significant, just that the two parts not be in direct contact nor the thermal interface of being glued together.

However as mentioned previously, a cap that had ran like this for a fair period of time already, plus considering this is the most heavily loaded rail in a system this PSU is most suited for, ought to be replaced to achieve longest life... or you can wait and see, but I hate to have to pull a PSu later when something can be pre-emptively fixed while the unit is open. Plus, it's not as though every last cap needs replaced at once, as they won't all fail near the same age unless there were some other severe problem like a fan failure baking the whole PSU or all of the caps were grossly defective rather than intolerant of higher heat. Since mine is still functional today without replacing all the caps I have to conclude they aren't grossly defective, but I don't recall what brand they were.

[JEWilson]

Re: Chieftec HPC-340-201 Rev C0 ATX12V

So far as we are referring to the problematic Chiefy as set out in
https://www.badcaps.net/forum/showthread.php?t=4461

I was only considering moving the cap in such a fashion as to be away from
the load res entirely but then considered (mid thought so to speak),
I may have to place shroud over the legs, as surely the lead length would increase
with such an endeavour and this might create other problems etc.

Upon reflection, it has been disconnected from the load res which I may
shroud, as you suggested. As it seems the norm with more modern psu,
I may just site an intake fan at the input grill to get more air into the
case. This in tandem with exhaust fan should do the trick and address
the sub pc thermal issue.

All the same, as you suggest, as a pre-emptive measure with these PSU,
it may be worthwhile replacing caps in the problem areas outlined.

Thanks

[999999999]

Re: Chieftec HPC-340-201 Rev C0 ATX12V

I have an oddity to report with this PSU. I have it running a Via C3 CPU based system, everything integrated (very low load), and formerly had at least two HDDs connected. I unplugged both HDD and booted a Ubuntu LiveCD, and noticed (only after OS loaded, ACPI pwr mgnt kicked in and video resolution changed) a wierd oscillation on the video output (video wiggles on-screen). Taking a 120Ohm resistor and placing it across the 12V-Gnd or 5V-Gnd changes the frequency of this, and connecting two hard drives completely eliminates it. Leaving no HDDs hooked up it produces faults and locks up the system eventually, though neither the 12V or 5V rails measure out of correct voltage range with a multimeter.

I have to conclude the PSU isn't stable running very light 5V load and almost no 12V load, that the resultant 12V rail instability effects 5V rail stability. It's kind of ironic that to use a very energy conservative system I'd have to add more fan or HDD load which increases the noise level.

[JEWilson]

Re: Chieftec HPC-340-201 Rev C0 ATX12V

Oops.

I've damaged an inductor in this PSU.
As usual, it has no markings on it. Checked the top of the device but found none

Therefore, I do not know the value of this device
It is a bobin type - two pins

diameter - 6.0 mm
lead pitch - 3.0/3.5 mm
height - 8.0 mm
value - unknown

FWIW the silk screen decal tells me its part L10 right beside the +5VSB
purple lead on the pcb.

The problem occurred recapping the PSU.
As usual the indocutor had been glued to a cap.
Removed the glue and it took the top of the bobin off the inductor.

Can anyone help?