Re: Server power supplies.. uh oh
Should've said something sooner - I don't offer that 90 day warranty for nothing. Expired now by a couple weeks.
I'd just replace the fan and run it some more....
Oklahoma Wolf
Badcaps Veteran
Last Activity: 11-26-2016, 12:46 PM
Joined: 12-17-2005
Location: Saskatchewan
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Re: Server power supplies.. uh oh
You need to draw the line somewhere... putting junk units inside a customer's server, whether they ask for it or not, is asking for trouble.
I have quite a few old review samples sitting around the house I probably could sell. But I have standards. I won't let something go out the door I wouldn't use personally, because if something leaves this house and then dies in an epic flameout the customer then blames me. "Well, you let me buy it, so it's your fault!"
The only one on the list I'd even consider...Leave a comment:
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Re: Gateway MX8739 - Dead
Yeah, this thing needs a new motherboard. Not sure I'm going to be able to do board level repairs on this one. She's a parts machine now.Leave a comment:
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Re: Gateway MX8739 - Dead
Chipset area is getting about a quarter of a volt. No power to GPU area.Leave a comment:
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Re: Gateway MX8739 - Dead
Nope - that's glue residue. There apparently used to be a shield on that part of the board - missing on mine, because someone's already been monkeying with it.
Can't find any liquid spill traces on the board. They may have been cleaned off by whomever got in here last, in which case the board is probably toast.
PQ51 pins 1-3 now have 4V on them. PQ49 pin 8 is still jumping around.Last edited by Oklahoma Wolf; 03-03-2011, 08:51 AM.Leave a comment:
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Gateway MX8739 - Dead
Picked up this 17" laptop cheap off eBay as a project. I've done about all I can do on it, and have pretty much hit a wall. Thought I'd post here and see if anyone has any ideas.
Symptoms are - it's dead. No sign of power anywhere on the unit. Battery claims to have a charge via the built in gauge, but I doubt it works... it also gives me nothing to work with.
Power jack has been ruled out - I've been working with it using soldered in wires running to a compatible power brick.
Here's what I have for measurements so far:
PQ51 (an AO4914):... -
Re: PC Restarting/ Shutting off abruptly.
That's because it has no display for it. It does take it into account. See the actual Brand specs here:
I've had it remain accurate when the KAW wasn't. It's not infallible, but until I start encountering the spoofers every week it's just not something I worry about. Two in three years is not a problem. When I start getting 100% efficiency every week, I'll know something's up.
At any rate, this is not a big enough deal for me to be willing to argue over it. Don't have the time. The IDRC...Leave a comment:
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Re: PC Restarting/ Shutting off abruptly.
Sorry, but this is not correct. They both do. I don't test for PF, but that doesn't mean I can't
The units that can actually fool them are few and far between. I've had only two in three years I think. Usually when the efficiency numbers are off in comparison to the 80 Plus test results, it means I have a test equipment failure to go find.
Had it happen not long ago when the Diablotek "1050W" unit blew out on the primary side. It fried the current measuring shunt resistor inside the Brand....Leave a comment:
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Re: Hp Vs17
Well, I think I may be giving up on this one. The replacement for the AP431 helped nothing. A nearby resistor (R824) that was supposed to measure 20k ohms read 34k instead, but replacing it had no discernible effect on the 5V output.
I'm now thinking the area I've been working on is in fact overvolt protection for the 5V rail. Don't know what else to try. The 5V Schottky connects directly to the transformer, which in turn connects to inductors on the PWM control side.Leave a comment:
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Re: Hp Vs17
/smacks forehead
Cross referencing... of course! I now have ten LM431's on the way. Will now wait and see what happens when I replace the regulator.
I'm not actually sure this is the PWM feedback circuit - it connects to it, but seems to only be there to regulate 5V supply. The fault has to be here somewhere since the 25V supply, also directly connected to the transformer, is working properly.Last edited by Oklahoma Wolf; 05-24-2010, 09:33 AM.Leave a comment:
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Re: Hp Vs17
That's what I was afraid of.
Dug a little deeper into the unit. The feedback circuit uses an AP431 shunt regulator, it looks like. Replaced the 4.7uF 50V Capxon attached to it - no change. Ref pin is attached to R824 - I measured 6.31V at one lead and 1.8V at the other.
I have a strong feeling the AP431 is defective. There's a variable resistor in the circuit - adjusting it does nothing. It's connected via R827 to the ref pin and R824. Other than that there are just a few resistors and capacitors in the circuit... can't find any issues with...Leave a comment:
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Re: Hp Vs17
Hmm... well, the 5V rail has been recapped - it's the only one I even had the replacement caps for. It's still at 6.31V. I've traced it back to D810, an SB1060FCT which in turn connects right to transformer T802. I'm not sure exactly where else to look for the problem. I don't have a replacement for D810 that I know of, and am not sure where to buy one. Lots of larger Schottkys, but not many that will fit this thing.
Edit - I found two STPS2045CT's - any comments on them as a suitable alternate?Last edited by Oklahoma Wolf; 05-23-2010, 11:39 PM.Leave a comment:
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Re: Hp Vs17
Some more progress made. As it turned out, I remembered wrong about how the inverter board mounts - it was easy to check the running temp of the components.
Observations - the only chip running hot is the GM2621 display chip. It wasn't bad when it first fired up, but after a while my brain made me take my finger off the thing. I could have held it longer, but it was getting uncomfortable. In the below pics, you can see the display board. On it, there are a ton of Capxons. Don't have replacements for any of them.
There's an AIC1084-33PM on the...Leave a comment:
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Re: Hp Vs17
That's what I thought. The topology of this one makes it hard to see what's running hot and what isn't due to short cables between parts. I need to find a way to run it so I can see what's overheating.
The supply for the Vcc seems to be coming directly from pin 1 of the bridge rectifier, a U4KB80R. I checked that pin four times when I saw the 61V... couldn't believe my eyes. Maybe I was checking the wrong pin, but I was going by the datasheet so I don't know what to think there.Leave a comment:
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Re: Hp Vs17
Nobody has any ideas on this one? I can't decide if this is more likely to be issues with the FAN7601 or the highish 5V supply. This one keeps tying my head into knots when I try to trace anything on it. Tried to find a Schottky I can use to replace the 5V part just in case, but no luck there.
I'm tempted to hack a little fan into the 12V supply and just leave it as is. It's not exactly the best LCD monitor out there anymore, and not really needed at the moment.Leave a comment:
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Re: Half success on AL1716
No problem - that one's got extra bells and whistles, which is why I keep ending up pounding my head on hard surfaces whenever I try to get it fixed. Ah well - I got the last Acer AL1716B fixed... it's a better monitor anyway. The HP has such a slow response time it's painful to watch video on.Leave a comment:
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Re: Half success on AL1716
Yep - it got buried with no responses.
[url]https://www.badcaps.net/forum/showthread.php?t=9599[/url]Re: Half success on AL1716<br /> <b...p?t=9599[/url]Leave a comment:
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Re: Half success on AL1716
Just an update. My new LM1117's are here, and U101 has been replaced after a brief fight with my soldering iron.
Monitor #1 is now fully working, as far as I can tell. So, this one was a complete success. Now if I could only get that HP VS17 fixed, I'd be happy.Leave a comment:
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Re: Half success on AL1716
Interesting... I never tried doing that with #1. Maybe there's hope for it yet. I decided I had to know for sure, so I have a batch of ten 1.8V LM1117's on order now. They were cheap enough to make it worth the gamble.
Thanks for all your hard work troubleshooting
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Hp Vs17
Ok, I've about had enough of this one. The patient, an HP VS17 (PK657AA), was given to me by a friend and is determined to send me to the crazy house.
Initial symptoms were the thing would turn on for a couple minutes and then go dead like the power was cut. Power button would not turn it back on. I went through it and touched up every bad solder joint I found, and replaced several capacitors.
That got it to run for a couple hours instead of a couple minutes, but it would always go dead again. Pointing a fan at it made it stay on indefinitely, but then if you tried to...Last edited by Oklahoma Wolf; 05-02-2010, 04:14 PM.
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