Ok so i work in a computer store. we have a pandemic of emachines comming in. common boards are fic am37 and au31. i have tested the capacitors and the fets. forgive me for being a noobie. both the caps and the fets test ok... i tested both according to posts i read on this website... hehe. what else could be a common factor between these boards. Most of the people that we buy our boards from know about this and charge a fortune for them. im sure that its just a vrm or something... any help from you guys would be great... thanks..
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Re: Emachine Mess
ok the customer describes the problem like this. "I was working on the internet an it just cut off" or "i went to fix something to drink and when i got back, the computer was turned off". I know basically that they have bad motherboard. We have a company that sells us these boards for alot of $$$. we also have to send the bad ones back and they fix them... the board symptoms are ;all the fans will power and the led's but no video. i have tried with the board out of the case, new power supply, different memory, different processor, and agp video card. same thing power but no video. usualy this happens after a power supply failure. a visual inspection of the board reveals no burnt chips, resistors, caps, no signs of physical damage at all. which makes the trouble shooting tough. i have tested the caps and the fets so far, both pass. my guess is that they use cheap power supplies and when it blows it takes out something on the motherboard. im fairly new at the component side of this but am very willing to learn. any help would be greatly appreciated. if you need more info let me know what you need to know and i will post it.
thanks.
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Re: Emachine Mess
Originally posted by zerologikmy guess is that they use cheap power supplies and when it blows it takes out something on the motherboard.
Sounds like a good guess to me - could you tell us a little more about the power supplies that are normally used by these systems? If it's a "mysterious" brand you haven't heard before, perhaps you could even take a picture of the insides of one, to allow us to, at least roughly, gauge the PSU's quality, or lack of it!
A quality PSU is absolutely vital to a machine's reliability. Badcaps may be bad, but a bad PSU can devastate a system's parts like little else.
Only a few months ago, in the Christmas vacation, my cousin asked me to troubleshoot his two-year-old machine that had "just died with a funny smell". The PSU, a Codegen "350W", had failed (never had a chance to find out why), with black burn marks all over on the secondary (output) side of the PCB. Also dead were: motherboard, hard drive, an attached USB stick (!), and even an internal modem that was sitting in a PCI slot. What did the PSU send down the +5v rail as it failed, I wonder?Last edited by tiresias; 04-06-2006, 06:53 AM.
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Re: Emachine Mess
I assume this is the PSU we're dealing with: (thanks to "dood")
https://www.badcaps.net/forum/showpo...0&postcount=82
On seeing that picture, I'd agree with Chris92 with regard to Bestec PSUs' quality - although I'd probably word it slightly more diplomatically myself.
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Re: Emachine Mess
im using a method i found on this site. vom. starts meter bumps to the right and then gradualy moves up until it reaches infinity
i also used the method on this site for checking the fets.
i hope this helps
and yes that is a picture of the power supply... but its blown so it will not be going back... hehehehe
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Re: Emachine Mess
I could use help with this too. Our church had an Emachines system with an AM37 board and the power supply's cap blew. I put in a replacement power supply from Antec that's ATX12V compatible but I can't get the system to boot. I tested the RAM & it's fine in another system. I've tested the CPU (an Athlon XP 2200+) and it works on an ECS board that I borrowed. I found a replacement AM37 board on Ebay & it won't boot either.
Any ideas how to get this to work? Either that or a good recommendatation for a replacement board?
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Re: Emachine Mess
lmc, in my torture testing, I have had (and currently have) caps whose C is in spec (though greatly reduced from the pre-test value), but the ESR is triple or quadruple the initial ESR. OTOH, I've also had caps vent but with an ESR that was close to the initial ESR. So if the caps are bulging, vented, or high ESR, well ... you know what to do.PeteS in CA
Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
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To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
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Re: Emachine Mess
I've seen that in my tests, but I measure the C and ESR daily of the caps I'm testing. In real life I wouldn't expect it other than a total coincidence in timing.PeteS in CA
Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
****************************
To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
****************************
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