BIG Problem
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From: MN on 9 Jun 2010 23:31 Paul, Thanx for the info. Please see my comments below (prefixed by ***) "Paul" <nospam(a)needed.com> wrote in message news:hun5fg$mug$1(a)news.eternal-september.org... > If you turn off the power, then remove both RAM sticks, the > CPU can still function at the next power up. What should happen, > is the CPU should be able to beep the computer case speaker. > (You need a computer case speaker, connected to the SPKR pins > on the PANEL header on the motherboard.) It might be > two beeps, then silence, two beeps, then silence and so on. > If you hear beeps, then it means the CPU is working a little > bit. If it still won't beep, then the CPU might not be > executing any code at all. *** There is no computer case speaker, nor are there any SPKR pins on the PANEL header. However, the mobo probably has a piezo-electric chip that can emit beeps. > Another way to prove the CPU is executing code, is to insert > a PCI Port 80 POST card, into the PCI slot #1 (that is the > PCI slot nearest to the processor). The codes don't mean a whole > lot, that flash on the card, but just getting the code value > to change, from the initial 0x00 or 0xFF value is an achievement. > You'd either have to borrow or buy one of those. They can be > real cheap when ordered from Hong Kong via Ebay, while if you > buy one from a local computer store, they can be $100.00. > > (This one from Startech is $40 or so. One reviewer says it > only works in 5V PCI slots, not 3.3V ones. 5V slots are > relatively common. I think all my motherboards here have > 5V slots. Some products like this, come with a second > display on the end of a ribbon cable, which makes it easier > to read the display.) > > http://www.startech.com/Share/Gallery/Large/PCIPOST.Alarge.jpg > > This one plugs into PCI and ISA slots. I only have one > computer with ISA slots here (11 years old). This one has > a second display on the ribbon cable, to aid visibility. > > http://www.elstonsystems.com/prod/pc_post_diagnostic_card.html > > Some limited number of motherboards, have four status LEDs. Some > even have the port 80 display soldered right onto the motherboard, > for easy reference. But to keep motherboard costs down, they > don't bother with that most of the time. *** A PCI Port 80 POST card is interesting, especially since the mobo manual lists 6 pages of Award post codes (although it is noted to be incomplete). However, I am first thinking of connecting my monitor to the mobo's VGA connector (within the I/O shield). Maybe there will be something on the screen. (I am hoping that the default BIOS video-output setting is for the video out to go to the VGA connector instead of the DVI connector, which is also provided.) > Asus used to provide a Winbond voice chip at one time, and it would > "speak" an error code. The solution probably cost a buck or two > per motherboard, but did add some value. But they've stopped using those, > and no other motherboard manufacturer seemed to be interested in > doing the same thing. I have a couple motherboards here, with that > error information voice device on it. The sound comes out of the external > computer speakers, via the green audio jack on the motherboard. > > Good luck, > Paul
From: John Doe on 9 Jun 2010 23:46 "larry moe 'n curly" <larrymoencurly my-deja.com> wrote: > I think you should test the mobo outside of the case, to rule > out any shorts between the mobo and case. There are many shorts between the motherboard and the case, that is in part the purpose for metal standoffs connected to motherboard conductive points. The likelihood of determining there is an unintentional short between the motherboard and the case is no greater than the likelihood of some random change causing the motherboard to work outside of the case. The case is an extremely good project holder for a motherboard, it should be used for that. If I suspected unintentional shorts between the motherboard and the case, I would test by using a different case. If you really knew what you were doing, you could use a continuity tester to determine whether there are any unintentional shorts between the motherboard and the case. And of course an ordinary user would have his computer turned off and unplugged from the wall before sticking metal probes into it for any purpose. -- > Be sure to set the mobo on top of a > non-metallic anti-static surface, such as the foam sheet packed with > the mobo or some pink transparent bubble wrap. Put that on top of > 3/4" brown cardboard, brown paper, or non-shiney newspaper. > > > Path: news.astraweb.com!border5.newsrouter.astraweb.com!npeer01.iad.highwinds-media.com!news.highwinds-media.com!feed-me.highwinds-media.com!postnews.google.com!n20g2000prh.googlegroups.com!not-for-mail > From: "larry moe 'n curly" <larrymoencurly my-deja.com> > Newsgroups: alt.comp.hardware.pc-homebuilt > Subject: Re: BIG Problem > Date: Wed, 9 Jun 2010 01:07:57 -0700 (PDT) > Organization: http://groups.google.com > Lines: 55 > Message-ID: <38ccdd79-5f64-4bb1-b6cd-884e1a5f0503 n20g2000prh.googlegroups.com> > References: <hum76n$ljd$1 news.eternal-september.org> <humb4d$333$1 news.eternal-september.org> <humgoh$7f8$1 news.eternal-september.org> <humrv5$fao$1 news.eternal-september.org> <hun42v$gdt$1 news.eternal-september.org> > NNTP-Posting-Host: 75.171.57.217 > Mime-Version: 1.0 > Content-Type: text/plain; charset=ISO-8859-1 > X-Trace: posting.google.com 1276070877 32479 127.0.0.1 (9 Jun 2010 08:07:57 GMT) > X-Complaints-To: groups-abuse google.com > NNTP-Posting-Date: Wed, 9 Jun 2010 08:07:57 +0000 (UTC) > Complaints-To: groups-abuse google.com > Injection-Info: n20g2000prh.googlegroups.com; posting-host=75.171.57.217; posting-account=nwMT4wkAAADJGK-3le1OljJcA4_llMcC > User-Agent: G2/1.0 > X-HTTP-UserAgent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0),gzip(gfe) > > >
From: larry moe 'n curly on 10 Jun 2010 00:00 John Doe wrote: > > "larry moe 'n curly" <larrymoencurly my-deja.com> wrote: > > > I think you should test the mobo outside of the case, to rule > > out any shorts between the mobo and case. > > There are many shorts between the motherboard and the case, that > is in part the purpose for metal standoffs connected to > motherboard conductive points. I mean shorts to ponts that aren't meant to be grounds, such as when a signal or voltage trace runs so close to a mounting hole that it touches the screw or brass standoff. > The likelihood of determining there > is an unintentional short between the motherboard and the case is > no greater than the likelihood of some random change causing the > motherboard to work outside of the case. But motherboards often work when removed from the case.
From: MN on 10 Jun 2010 19:03 Thanx for your suggestions. Please see my comments below, prefixed by *** ============================================================================ "larry moe 'n curly" <larrymoencurly(a)my-deja.com> wrote in message news:38ccdd79-5f64-4bb1-b6cd-884e1a5f0503(a)n20g2000prh.googlegroups.com... > > > MN wrote: >> >> *** Regarding the "similar" 4-pin connector: I measured +5 volts on it >> when >> I had both ATX power connectors NOT connected to the mobo, and the PS_ON# >> to >> COM jumper in place. This +5 volts was measured AT THE SAME TIME that I >> measured (and found correct) the voltages on both ATX power connectors. >> Comment: this +5 volts on the "similar" 4-pin connector is LESS than the >> +12 >> volts that the correct 4-pin connector supplies. This is in "my favor" >> since >> the +12 volts that the mobo expected is greater than the +5 volts I >> possibly >> erroneously supplied. Also, (1) after I connected the correct 4-pin ATX >> connector AND the 20-pin ATX connector (no jumper, of course), and (2) >> applied AC power, and (3) then pressed the case power button, I got the >> BLUE >> LED to illuminate and was able to manually operate the CD/DVD from the >> front >> faceplate. Thus, I believe that my original "application of +5 volts >> instead >> of +12 volts" on the 4-pin connector did NOT damage the mobo. TO DO: I >> need >> to check into the voltages applied to the fan connector when the mobo has >> power applied. >> >> QUESTION: SUPPOSE, I did not have the 2 sticks of DDR2 memory in their >> sockets, what would be the symptoms? If, for any reason the >> read/write/refresh RAM memory cycles were not correct (incorrect default >> BIOS memory timing, SPD,etc), it would be as if no RAM memory was >> present. >> Thus my question. In other word, isn't the CPU "dead in the water" >> without >> correctly functioning DDR2 RAM? > > First of all, I wouldn't test a new computer with the disk drives > installed but the keyboard and monitor not connected because the video > and keyboard can indicate some signs of life in the computer. At > least you had the mobo speaker installed. *** I connected the monitor and keyboard to the computer. Then I plugged in the AC line cord, and pressed the case power button. The case power BLUE LED illuminated and I was able to manually perform CD/DVD tray ejection from the front faceplate, just as before I had a monitor & keyboard connected. There was NOTHING on the screen and NO beeping. (There is no case speaker, and NO pins on the mobo PANEL header to connect to a case speaker. Therefore, I assume there is a piezo electric chip on the mobo to do any beeping.) CONCLUSION: the bios is not executing because the CPU is not running. > Another thing I do with new mobos is first remove the CMOS battery > because when the CMOS clock memory contents is gone, most mobos will > turn on instantly when power is applied, even before the power switch > pins on the mobo aren't shorted together, plus the CPU fan will > probably run at full speed, rather use any quiet mode that may not > turn on the fan until the CPU warms up enough. *** I will try this, but will it help if the CPU is not running? > I have a feeling Paul is right about damage occurring because the two > different square 4-pin power connectors were mixed up. Connectors are > supposed to be molded to make that impossible, but that wasn't the > situation with my Ultra V-series PSU and a cheap ECS mobo. It's > possible that damage was limited to a protective fuse (flat > rectangular surface mount thing, often black or green on top and > marked "F" or "X" on top or on the mobo) and diode (diode may have > blown the fuse and shorted in the process). These devices are often > near the power connectors. Try measuring the resistance across each, > in both directions. *** I don't think I caused any damage because the incorrect 4-pin connector supplied +5volts instead of the normal +12 volts on the correct connector. > I think you should test the mobo outside of the case, to rule out any > shorts between the mobo and case. Be sure to set the mobo on top of a > non-metallic anti-static surface, such as the foam sheet packed with > the mobo or some pink transparent bubble wrap. Put that on top of > 3/4" brown cardboard, brown paper, or non-shiney newspaper. *** I will take the mobo out of the case. But if it is not grounded to the case by the mounting screw/standoffs, won't this be a problem?
From: Paul on 11 Jun 2010 04:49
MN wrote: > > *** I will take the mobo out of the case. But if it is not grounded to the > case by the mounting screw/standoffs, won't this be a problem? > Ground is provided in three ways on a motherboard. 1) The black wires on the main ATX power supply cable are ground. 2) Where the conducting motherboard tray standoffs touch the bottom of the motherboard, on the plated_thru holes, is ground. The purpose of the ground, may be for RF emissions control, rather than DC current conduction. 3) The I/O plate inserted in the computer case, has shiny springy metal contacts. They press against the I/O stack shiny metal body. That causes chassis ground to electrically touch and contact the stack. That is for ESD discharge and RF EMI control as well. If you place a motherboard on a cardboard covered telephone book, you lose (2) and (3), but (1) has you more than covered. The DC return currents continue to flow over the black wires and all is good. I've built and tested two computers, sitting on telephone books, and they worked fine. No instability, no complaints. Once tested, I disassembled and placed the components into the case as normal, knowing all the hardware was working. Paul |