MoBo or What?

A friend? gave me what would be the crown jewel of my computers . If I could just get it to work.
This is a generic assembled computer here`s what I have tried.
Downloaded a users manual for an EPOX EP8K7A+ Mother board.
AMD761 Chipset
The CPU has AMD on the chip in the CPU Socket A, that`s all I can read in the chip.
I AGP Slot
6PCI slot
The Video card is a eVGA.com graphics accelerator card. Complete with cooling fan and a bundle of Disks for drivers etc.
Dimm-1 has a stick of memory, nothing in 2.
The (known good) monitor is blank, no post, no nothin`.
The MoBo turns on,from front mom. contact switch, fans power up, Power light on. there`s two 7 bar LED`s at the bottom of the board that only light partially,fully lit they`d both be a sideways eight one lights an upside down "C" the other a horizontal "I" two bars. The chips are designated GAL16V8 on the MoBo, are they a trouble shooting assist? Don`t know, just a hunch.
The only things connected to the computer are the mouse, monitor keyboard, and the 3.5 floppy and video card in the AGP slot.
I tried another video card in a PCI slot Blank
The only sign of life I`ve heard was a single beep on boot up when I removed the memory sticks and turned it on.
I also cleared the CMOS after trying several other things first
The battery reads a full 3V.
Kiss it (sob, sob, ) goodbye?
Moore

 

Do you have a video card that will work in the PCi slot? Dunno but maybe in the BIOS you can select AGP or PCI? Just guessing though. Check ram and make sure it is ok. Is the power supply good? Look in the manual for the beep codes. 1 beep usually means all is ok, at least for ASUS boards.

 

I never thought about trying to get into the Bios from a blank Screen. Is it your contention I could bring it up by keying delete, or whatever, on the key board while guessing what the POST is doing?
It`s got a 450 watt Power supply. I haven`t checked voltages, but I will.
I tried a good video card in a PCI slot, to no avail. Thanks,
Moore

 

Moore,
No i misunderstood your initial post regarding the blank screen so it not my contention that by pressing delete you will be able to access the bios. Sorry for that.

 

If you can read what is on the CPU chip, does that mean that there is no heatsink and fan on it or are you removing them?

This may mean "infinity degrees Celcius ". It may be overheating. Have at look at the tutorial here: www.arcticsilver.com .

Matt

 

Yes I took the heatsink and fan off to read the chip. But I`ve never turned it on without the heat sinks and fans removed. They were all nice and clean, minimal dust, and horsehair, and cockleburrs, like I`ve seen on some units. Thanks from `Rooland,.
Moore

 

Guess I`ll lay her on the shelf in the back room. Thanks, as usual, for all the replys.
Moore

 

hang on in there

these are 7-segment diplays, right? Are the lit segments fully lit or do they appear dim

try pulling out all plugin cards if there's basic onboard video - if no onboard video try with only the PCI video card (suspect short on a plugin card) (several supplies, just having fans and LEDs working doesn't mean the supplies are all OK)

==

GAL16V8 are programmable, they can be almost anything depends upon what they are set up to do

**edit GAL16V8 can also be other things! ...if that's the numbre on the 7-segment displays then it's just the number for the display, and they are indeed probably a troubleshooting aid

==

do you have access to a voltmeter, pls

best wishes, HJ.

 

strewth - 8.5MB for the manual??? - back later... HJ

 

hunch

could that upside-down c and horizontal line perchance be interpretable as U- please? If so then it probably means your negative supply rail's low or missing, can be due to short on plugin card, naff PSU, several other not-terribly-awful possibilities

just came across baord with shorted supply; small metal object (clip that hold in RAM module) had broken off and caught under the board. Could have been nasty but it wasn't - nothing precious had been destroyed - removed offending object and computer worked fine...

that manual's still dribbling in (am on dialup), BW, HJ.

 

Downloaded a users manual for an EPOX EP8K7A+ Mother board.
AMD761 Chipset
The CPU has AMD on the chip in the CPU Socket A, that`s all I can read in the chip.
I AGP Slot
6PCI slot
The Video card is a eVGA.com graphics accelerator card. Complete with cooling fan and a bundle of Disks for drivers etc.
Dimm-1 has a stick of memory, nothing in 2.
The (known good) monitor is blank, no post, no nothin`.
The MoBo turns on,from front mom. contact switch, fans power up, Power light on. there`s two 7 bar LED`s at the bottom of the board that only light partially,fully lit they`d both be a sideways eight one lights an upside down "C" the other a horizontal "I" two bars. The chips are designated GAL16V8 on the MoBo, are they a trouble shooting assist? Don`t know, just a hunch.
The only things connected to the computer are the mouse, monitor keyboard, and the 3.5 floppy and video card in the AGP slot.
I tried another video card in a PCI slot Blank
The only sign of life I`ve heard was a single beep on boot up when I removed the memory sticks and turned it on.
I also cleared the CMOS after trying several other things first
The battery reads a full 3V.

Yes I have a voltmeter. As per above( original post)the only thing connected is the monitor, keyboard, and, mouse.I`ve got the MoBo out of the case at present and looked it over closely. No sign of a short, or any foreign objects.
__

i__i
the Diplay looks (something) Like above. The MoBo download is 88 pages IIRC.
Thanks
Moore

 

having had a look at the manual (should really have done that first ! but you were sounding like giving up)

if you turn round your view of the board 90degrees - orient yourself by the decimal points in the 7-segment displays like this which I would call 1C - does it read C1 or 1C ?? (pls check)

- because if it's C1 it means
1.Memory insert inappropriate
2.Memory compability problem
3.Memory Bad
(from p2 of the PDF)

this has to be your first port of call?

(very baffled about the detailed table of codes right at the end - hope we don't have to resort to that one)

===================================

ahh - just seen your post - this is C1 then I take it - so a memory thing?

doing this with the memory out then... and was the display the same when the memory was still fitted?

also - as you have a voltmeter we could suss the PSU voltages to good advantage, always good to rule out PSU problems otherwise can get nowhere fast...

==

(the green arrows and yellow ring indicate bits of the hardware which might need a check later on - if it turns out not a memory issue)

(now I've seen the picture: those GAL16V8 are indeed programmable logic arrays)

best wishes, HJ

 

`Twould indeed be a CI. A pity I couldn`t decipher those codes. I read them but not familiar enough with this computer jargon to translate!
I`ll put things back together, and boot it up with and without the ram so I can answer that question. As for checking the power supply voltage can I check it by powering up and taking readings on the plugs like from black to red and yellow to red, or is there a better place on the board to check?
So you`ll know, I`m a senior citizen, retired electrician, of fifty some years in the trouble shooting business. I know my trade but am just learning about yours. Electronics technician I am not! I certainly feel with your help I`m at least not groping around, blind.
Thanks a whole bunch. I`ll be back.
Moore

 

Moore -

re: the PSU readings - I'd go for it where the cabling from the PSU goes into the back of the connector which plugs into motherboard - on load - use one BK as your reference, check the other BK(s) isn't too far adrift (!) ( ~30mV is OK but any more than that, start thinking) - hairy big currents so expect there may be a little between them down to (in)efficiency of crimping, connector resistance, ?dry joint on the motherboard)

(not as good measuring at HDD connector - appreciable voltage drop over the wire to the motherboard)

assuming BKs agree-ish, measure all others re: BK

==

the only voltage we might need measured from the motherboard itself is the core voltage - yellow ringed area looks like the regulators - cross that bridge if and when we need to.

comparison of these is surely what we need first off.

==

green arrows were to indicate elcaps, inspect all such visually: look for signs of any bulging particularly the ones near the PSU connector and the core voltage regulator

==

I'm being invaded by inlaws! - gotta go - will check back later, see how you have got on.

Good luck! and best wishes, HJ.

 

Voltage:
Bk to BK on plug to MoBo under load, 20 mv. max.
R-B 5.00 Volt
Y-B 12.19
Boot without Ram stick, E2 on LED`s
Boot with Ramstick in wrong slot, E2
Boot with Ram in proper slot, back to C1
Thanks
Moore

 

Hi

E2's a bit of a puzzle, they don't seem to list it

however from the C1 with it in the correct slot: I'd suspect
- memory u/s
- memory wrong speed or otherwise incompatible

can you test the memory in another machine somehow?

best wishes, HJ

 

This machine has worked for the previous owner with this memory when he had it. I think I`ll double check that with him and if that`s truly the case I`ll order a new lower priced stick from Crucial on a gamble that that will make it boot. If it does I can always get more Ram. Whaddya think?
Moore

 

hmmm - well, memory can get damaged, it would be useful if it could be tested in another machine - alt. try another stick like you say...

I'm rather worried about those E2's as well - in that I would have guessed that for a problem as fundamental as "no memory fitted" they would document the error code in the brief section at the start of the document - so a bit puzzling - and it's not in the other section (Appendix A) either

(I'm sorta taking it that Appendix A lists the codes which you get if certain parts of the POST sequence fail - although it's far from clear from the way it's written)

the course of action you suggest seems the most sensible - unless someone who knows the board better than we do can come up with something

will see if I can dig anything up, and will surely check back anyway to see how you're getting on - but probably tomorrow as need some kip!

best wishes, HJ

 

It may be as much as a few days . I`ll post back to this board. I went over that users manual with my inexperienced eye and decided there has to be some information on there that I don`t know how to find.
I`ve got quite a few stcks of memory, that I have saved out of junk computers, but nothing compatible. You certainly have been a pleasure to work with!
Thanks,
Moore

 

although I couldn't get anywhere with E2, there's mention here of a similar C1 error when board fitted with known good RAM - together with strong hints towards (they say) soldering etc - intermittency of some description

they don't mention a few things in that "department" - one's a horror: plated through holes (vias) not being plated through enough... another "killer" is hairline crack in SMD or leaching at the end caps. But...

...other things can do this which are easy to check for - there are three chips I can see socketed on that board - the two GAL16V8 PLAs and also the BIOS chip itself. After thermal cycling you can certainly get contact problems on the style of socket they've used for the PLAs...

what I usually do is to press down gently on first one end, then the other, of the IC itself - to try to get a slight shift as the IC moves down a tiny bit - can almost always feel a tiny movement. This has the effect of scraping off surface film... Doesn't cost and has worked for me several times (Jermyn IC sockets back in the '80s: almost every time - and they were gold plated and meant to be good)

Could do similar to the BIOS chip - ringed in magenta on the picture (earlier link) - you don't have to take the devices out, just try to rock one corner, then the opposite corner down. (IE: CtrlF5 to refresh if you're stuck with the previous image)

Also would be worth inspecting the underside of the board - particularly in light of what they say in that other thread about pressing down on one corner of the board to make it work. Pay particular attention to PSU connector to board soldering (classic appearance is a ring around the pin - lens! - you can't always see it though - sometimes you can actually wiggle the pin...)

reckon it might well be the BIOS chip because it's so close to where the board mounting hole is - would expect it to get flexed around there

zzzzzz, HJ.