cpu and motherboard id?

hello,
pentium p54c 100 mhz, amibios @1985-95 american megatron f818733
intel pciset sb82371sb L6441225 suo93 intel m c '95
intel pciset sb82437vx L6434455 su116 intel m c '95
briefly reseated ram and pc stopped video, then few boots wouldn't shut off, then floppy drive wouldn't work and the hd light is not lit (but the power light comes on) but it spins
have removed and reseated and replaced cables etc. but same result: powers up but no post.
i assume the moBoard is gone and need to know how to find out what types of boards i can use to replace. if anyone knows of a site that would have a diagram of the cpu and how to find the s/n i would appreciate it...(intel doesn't support this chip; the manufacturers don't reply; and there is no manual)
i don't know whether the above numbers are a help or extra clutter -- sorry if it's the latter...
THANKS!

 

hello,
thanks very much for the reply!
unless i am missing something in the instruction / pro user's guide, i think that the pc needs to be running?
this one is not... it won't post... the power / fans come on and the on indicator light comes on but that's it....
i believe the board is gone so i need to id a dead pc...
i am dLoading the program b/c i do have other ones here that are booting
thanks again!
sincerely
Tanya

 

Hi Tanya- look at where you plug the keyboard in. If the port has 5 holes, it's an AT form factor motherboard. If it has 6, its an ATX or one of its offshoots like NPX or LPX. Check the keyboard port first. Are you trying to reuse the CPU and RAM?
Clydeo22.

 

hello clydeo22,
thank you for replying!
the kb port has 5 holes below and 1 above (i.e. 1 at 12:00, and 1 each at 4:00, 5:00, 6:00, 7:00 and 8:00.)
total 6
as far as replacing the cpu: not sure how to even find the s/n (there's what looks like a heat sink with green vertical bars; there's a metal clamp over this (at right angles to the front and back of the pc) (it's a desktop not a tower) and next to it is a connector...(parallel to the front and back of the pc -- btw the expansion slots and memory banks are also parallel to the length of the computer))
it's a p54c however i cannot find any diagram...)
would you know where to find a diagram / instructions re: identifying / removing / reseating the cpu?
these are simms 8 mb and replacing isn't a problem
this is a vtech nrv platinum series?
thanks again!
sincerely
Tanya

 

Hi Tanya- You have an AT form factor motherboard so that's a start. Finding one won't be easy but certainly not impossible. You have to match the form factor of the motherboard and case. I assume that the p54c is your processor and if so, it will fit in a socket 5 or 7 motherboard. So, you need a socket 5 or 7 AT form factor motherboard. Here is where you can find a motherboard or motherboard manual for a P54C:
http://x86.ddj.com/intel.doc/intelmotherboards.htm
Post back with your progress when you can and we'll go from there. Clydeo22

 

hi clydeo22
just an interim THANK YOU for the information and for the Web site!
sincerely
Tanya

 

Hi Tanya

RAM problems can give some of those symptoms you mention. Before you take it apart, try cleaning the connections of the RAM sticks. You can use a soft pencil eraser, I use Contact Cleaner which you may be able to get from the local hardware or electronics store. You can spray CC into the motherboard slots as well (make sure it has completely dried before repowering the machine).

It will probably use 72 pin RAM in matched pairs, make sure the pairs are seated side by side. If it has 4 or 6 sticks, just try 2 (matched).

I would be concerned if you went to the trouble of getting another motherboard only to find the problem was the RAM.

It would be good to test the video as well. Is the monitor working on another machine?

Matt

 

hello Matt,
thanks very much for replying and the advice
the problem started / escalated after i'd tried to reseat 2 of the (72 pin) RAM chips
no post; no video
i removed them and it had several posts and video then the floppy stopped working (light stayed off)
reseated all ram (i have and will try the contact cleaner now)(also replaced 2 chips)
replaced the floppy cable (with the twist) and the light stays on or off)
pin 1 is where it should be)
the monitor does work...
i've removed most everything in steps (video, modem, hd ide and power connection and floppy connections (power and data cable) -- and 2 of the 4 RAM chips))
(each time no post or codes)
it does the same thing: lights up and fans run but no post (no beep code either)(have replaced battery)
another reason that i need the motherboard id is there are ?dip switches and jumpers and i am not sure re: their proper positions (in case something was knocked closed / off)
appreciate your reply and will use the cc now
THANKS!
sincerely
Tanya
p.s. i might try another video card...?

 

You've covered everything well! Still looks to me like a RAM recognition problem. A check of the motherboard and if it could access the RAM would be to remove all RAM and make sure it gives the "no RAM" code (beeps).
After using the contact cleaner you may want to reset (clear) the CMOS by using jumpers or by removing the battery for more than 30 seconds.

I have fixed/passed on a few of these older machines and thought about upgrading them, but the parts are expensive compared to the latest equipment and they are miniscule by comparison. You should weigh up the cost of getting it going again against the cost of another (larger) machine or a basic new model (only a few hundred $'s nowdays). Looks like you've gotten some invaluable experience though

Matt

 

hello Matt,
again, thanks for the reply!
i have not used the radioshack cc *yet* since there are no directions and the salesman there said not to use it on the board -- just on a cloth to apply it to the chips' contacts
want to make sure it's the right kind: has isopropyl alcohol, isoButane and N-propane.
is this the right one? it seems to evaporate quickly...
i wanted to spray all of the slots and the contacts on the v. card, ram, sound card and modem.
i still don't have the mobo id'd however i have 4 other pcs here with <superficially> the same design... in various stages of functioning -- none well
following the cc i'll try with no Ram chips...
i thank you very much again, the unfortunate part is that these are not mine and the person they belong to does not want to buy anything including a new <currently> very reasonably priced pc.
for me this IS very good experience especially with the help i have / am getting from you all on this forum!
i did remove the battery but will do that again following the cc and the ram test that you suggest
THANKS!
sincerely
Tanya

 

Tanya,

The advise from the salesman sounds OK. Do all the contacts RAM, video, etc, it certanly won't hurt if you are careful. With that contact cleaner you would have watch out for trapping alcohol fumes in the case and ignition from a spark. Read the directions carefully, make sure all fumes have disapated.
Spray the slots, I may have to leave that up your discretion. I have done it when all else has failed and it worked for me. Take care not to trap alcohol fumes in the case if you do. (If you can tilt the board so that the residue drips "out ", then great).

Matt

 

Thanks again, Matt!
(i have used the cc on the memory contacts video and sound card contacts)
i have not sprayed the "made for integrated circuits...memory disks...printed circuitry" cc in the board slots yet... i tested with NOTHING on the system and no post or beep codes... and
cleared the CMOS (i.e. removed the Li battery) and reChecked then w/ 2 then 4 chips)(only the fans and the on/off light)
i've used the compressed air...
not finding this EXACT board on the Web site that was posted however i did find that the cpu *IS* socket 7 (written right on the connector next to it)
i'm looking for some kind of a jumper that might reSet things...
if i find it and it has no effect then i'll use the cc in the slots.
the pc case is off and it's well ventillated (and unfortunately the cc product has no directions just says what it's used for / on.)
there are 4 systems here in varying degrees of functioning...
2 have cpus in socket 3 and another's (tower)cpu is in socket 7 however the mBoard is several inches (2) longer front to back than current one) the final one doesn't state the socket...
Thank you very much again!
sincerely
Tanya

 

Hi Tanya- from what you and Mattman have found, the motherboard is toast. You don't need to match the motherboard model, so identifying the manufacturer of it is not really a concern. What you do need to do is to match what is called the form factor. You have an AT form factor case so you need to get an AT form factor motherboard to fit in it. You can double check the form factor by measuring the dimensions of your current motherboard and posting your findings here. If you want to reuse the CPU, that particular one will work in either a Socket 5 or a Socket 7 AT motherboard. You also might want to try your RAM (SIMMs) in another machine before going forward as if they are no good, that will be another expense to figure in. Try the link I posted earlier for more information on motherboards. Best of luck, Clydeo22

 

No beeps when there is no RAM, that looks like the motherboard has gone ( the motherboard speaker should be functioning, you got a single beep when it was running?), although now I wonder about the power supply.

A lot of the parts should be interchangable with the other Socket 7 board (you will need to set jumpers to change the CPU). I hope between them you could make a working system.

To test power supplies I generally find that if you set the two computers side by side the power leads from one will stretch to the other. Make sure the coloured wires on both motherboard connectors are the same (proprietry makes like IBM, HP etc can have their own wiring system and will fry another board).

I cannot find information to ID that motherboard. It was made when "IBM clones" were prevalent and a lot were made by small companies that are no longer around (an FCC ID number is what you need, but some non US boards did not have them in those days). If the board was running before and you have not changed any jumpers and it has no switches, then the only "reset" would the CMOS jumper which is the same as removing the battery.

Try a search on P54C, P54C manual, P54C specifications, etc. you may be able to match a diagram to the board eg. there is a diagram here: (second link)
http://oldman.ixbt.com/mb/P54C/


Hope some of this helps

Matt

Edit: Had the wrong url, changed it.
Don't spend too much time on the power supply, it's only a "maybe ".

 

hello clydeo22 and Matt,
THANK YOU again very much for replying and for the information!
i upLoaded 3 photos of the board here:
http://pws.prserv.net/cainet.tjtmd/kpPCRedo.html

the dimensions are 10" X 9.5" inches (10 inches front to back of the desktop (not tower) PC
(the slots are parallel to the long axis))

i don't have a socket 5 board (unless the unMarked one is)
i'll check the memory however another pc's memory had not worked in the <current> computer

i have found the intel motherboard link that you posted EXCELLENT and am using it thanks again for posting it, clydeo22!

***
There had been a POST before... so the pc speaker had functioned...

re: the psu...
before removing any of the connectors i thought that (99.9%) certain that black was in the middle (i.e. ground)...)
(another pc was already unplugged)
aside from 2 they are labelled... (color coded)
could i test the connector with a voltmeter (i.e. power on the pc (with the psu connectors unplugged -- all power connections unplugged)) and probe a black wire (i.e. where it would plug into the board) and pc ground and if there is no voltage, assume that the black wire is ground + test the orange wire against pc ground and if there is a voltage assume that the psu is conventionally built (i.e. black / ground goes into the middle?)
i really appreciate the psu info and the caution!

there are jumpers +/- DIP switches ... none were changed intentionally but maybe got knocked -- i'll look for an fcc id also............

Thank you VERY much for the cpu museum link it is EXCELLENT!

again, i thank you both very much for the help -- GREATLY appreciated!
sincerely
Tanya

 

Hi tanya- I see you've been keeping busy. If you are referring to the power connectors that go to the motherboard, they are known as P8 and P9. The black wires of the two must both be in the center (next to one another) when you reinsert them. If you test the power supply, it must have a load on it when you are testing in order to get usable readings. If your power supply isn't shot but just intermittently flaky, this test won't rule out the power supply being the source of intermittent problems as it is unlikely that you will be testing it at the moment it decides to act up. You can get a BabyAT motherboard from Computer Surplus Outlet for around $15. They also have 72 pin SIMMs (the type of RAM your motherboard uses). I found a great site for jumper settings of all kinds of old hardware here: http://th99.pley.org/
It has a section for motherboards as well. Keep us posted and good luck. Clydeo22.

 

Power connector pinouts:
http://www.hardwarebook.net/connector/pc/motherboardpower.html
As clydeo22 says, it needs to be "under load" when tested with a multimeter.

Still no luck with the M/B ID. Have you been able to find any other numbers on that board? Check around the edges and between the PCI/ISA slots.

Matt

(Some thing that is rarely thought about...check that a wondering s.crew has not found it's way under the motherboard and is causing a short.)

 

hi clydeo22 and Matt,
again very grateful for your replies and information, links etc
THANKS!

re: testing the psu...
to test i'd have to disconnect ALL the power cables on the machine i'll use to test? (i.e. to the working system's hd, floppy, etc?)
(and just try for a 'no memory' beep code in the <current> pc?)

(also i can assume that the psu is good even if i get beep codes?) -- none of the AT pcs are actually running but they all are giving various beep codes (aside from the <current> pc)...

i found the computer surplus thanks for the info and the jumper setting site is GREAT!

as for testing the psu actually the board, i have a text that has the grnd lead on the psu and the testing lead (of the voltmeter) on various areas of an ISA slot (B3, B5, B7 and B9)

another book i have discusses testing the board resistances using the black probe on 8, 8, 8, 5, 6, and 7 against a VOM (voltmeter-ohmmeter) lead and if any of these 5 readings are < than minimum then the board is dead...
not too clear on this one...
i cannot relate the ## to the link "connector motherboard power "

i'm not having much luck id'ing the board there are a number of "plates" with writing on them which i will post shortly
just wonder re: the intel pciSet numbers
intel pciset sb82371sb
L6441225
SU093
intel m c '95

intel pciset sb82437vx
L643445
su116
intel mc '95

i don't think there is an object (the word ***** comes up as asterisks???)
under the board but will definately make sure!
ok LOL s.crew
i'll post all the ## shortly
THANK YOU very much again for the replies, the sites, the information, the help etc
really appreciate it!
sincerely
Tanya

 

Hi tanya- to test the power supply, you want it to be under as close to same load it is under with everything plugged in. So- to test the leads that go to the motherboard, have all the drives plugged in while you are testing. Power down, then plug the motherboard leads in (black to black in the middle) and unplug the drives one at a time to test them powering down before plugging and unplugging. Once again, you don't really need to know the manufacturer of the board, you just need the right size and a socket that will accomodate your CPU. Many older boards were made by companies that have either folded or been swallowed up so even if you can decipher the hieroglyphics enough to determine the maker, they are long gone. That is why I try places like Computer Surplus for the oddball part. Good luck. Clydeo22