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motherboard connector mystery

A

Amigaz

Experienced Member
Joined
Jan 31, 2008
Messages
426
Location
Stockholm, Sweden
have finally been able to put the motherboard on the pic below the the test after replacing the dead dallas circuit with a replacement and socketing it.
hve encountered a problem, have no clue on how to connect my case cabling/connectors except the reset switch which is the bottom two pin connector in the row of case connector on the motherboard....this mobo is one of those lovely motherboards they wanted to be unknown
is there a way to check these pins with a multimeter to determine what they are?
 
Amigaz said:
have finally been able to put the motherboard on the pic below the the test after replacing the dead dallas circuit with a replacement and socketing it.
hve encountered a problem, have no clue on how to connect my case cabling/connectors except the reset switch which is the bottom two pin connector in the row of case connector on the motherboard....this mobo is one of those lovely motherboards they wanted to be unknown
is there a way to check these pins with a multimeter to determine what they are?
Click to expand...

I think just above the memory slots would be a good place to start. May you take a detailed picture about that area, including the "soldered" side?
 
Have you tried the hardware section at AOH?

Link

They have a rather large visual library of old hardware with jumper settings and component locations.
 
What else would there be - a keylock switch, power-on LED, and speaker perhaps? This board looks too early to have those combined into one pin header like the later ones, they are likely mostly separate.

Certainly with just a power supply, video card, and keyboard you should be able to boot to the BIOS without anything connected and test for the LED and speaker.

It looks like they are located at the right, around W17. If I recall, the speaker is a 4-pin, and two functions were combined into a 3-pin perhaps keylock and power LED.

edit: oh, and of course the turbo switch...
 
Last edited:
A lot of boards with that kind of memory board slot were made by Micropolis. If you go looking for it on TH99, you might want to look there first before searching thru all the 'unknown/other diagrams.

--T
 
The serial ports should be pretty easy. Back in my old clone days when I ran a repair shop the 9 pin ones had 2 different pinouts on the motherboards and expansion cards.

1 2 3 4 5
6 7 8 9

or

1 3 5 7 9
2 4 6 8
 
paul said:
What else would there be - a keylock switch, power-on LED, and speaker perhaps? This board looks too early to have those combined into one pin header like the later ones, they are likely mostly separate.

Certainly with just a power supply, video card, and keyboard you should be able to boot to the BIOS without anything connected and test for the LED and speaker.

It looks like they are located at the right, around W17. If I recall, the speaker is a 4-pin, and two functions were combined into a 3-pin perhaps keylock and power LED.

edit: oh, and of course the turbo switch...
Click to expand...

Yes..I know they probably are what you tell..the 5 pin is definately the keylock/pwr led header...what I'm unsure of is which of the 4pin headers that are the speaker header
I guess in the "dark hardware ages" the turbo switch connector had 4 wires and there was a seperate black wite which switched the led display?

The headers on my mobo look like this:

.... = speaker?
..... = keylock/pwr (pretty sure about this one)
.... = turboswitch??
.. = reset switch (confirmed)

RAM SLOTS
¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
 
Terry Yager said:
A lot of boards with that kind of memory board slot were made by Micropolis. If you go looking for it on TH99, you might want to look there first before searching thru all the 'unknown/other diagrams.

--T
Click to expand...

Sadly there's no motherboard by Micropolis listed there..
 
channelmaniac said:
The serial ports should be pretty easy. Back in my old clone days when I ran a repair shop the 9 pin ones had 2 different pinouts on the motherboards and expansion cards.

1 2 3 4 5
6 7 8 9

or

1 3 5 7 9
2 4 6 8
Click to expand...

Yep, even pin no.1 is marked on these headers and what is com 1 or 2 :)

Edit: I was seriously wrong about this
 
Last edited:
On my motherboards, the 4 pin connector for the speaker uses the outside pins with the inner two empty. As the speaker is a A/C signal, it has no polarity. Get out your volt ohm meter and see if any of the 4 pins has a +5v on it. If so, then likely NOT the speaker connection.
 
Ok, I got the speaker wiorking + powerled
Have one 4pin header left I thought was the turboswitch/turboled but I'm not sure anymore
I checked the two pins to the farthest right witg my trusty fluke 78 and found out that one gave 5v and one was grounded so I figured that was the turboled but nothing happens when I put that cable + connector there...the turboled won't go turn on.
The two pins to the inner left showed hogh ohm reading so I figured they might be the turboswitch so I hooked up that cable + connector and tried but it didn't change anything when testing the cpu performance on Norton SI which I usually use when I test things like this..
Have I done something wrong? is it the pins I believe was the turbo led that is the turboswitch? guess not?
As you can see on the below photoes there's a couple of two pin headers near a clock crystal which I'm not sure what they are.
The back plate of my tower case obstructs the view of the mobo at the back so I can't take any pics there.

http://picasaweb.google.com/jivemaster2005/Old386?authkey=JQ-Oy0840lM&pli=1&gsessionid=FNQR_phCML-j7EkwRORQqQ#5262324311434132034

http://picasaweb.google.com/jivemaster2005/Old386?authkey=JQ-Oy0840lM&pli=1&gsessionid=FNQR_phCML-j7EkwRORQqQ#5262324158697943218
 
channelmaniac said:
The serial ports should be pretty easy. Back in my old clone days when I ran a repair shop the 9 pin ones had 2 different pinouts on the motherboards and expansion cards.

1 2 3 4 5
6 7 8 9

or

1 3 5 7 9
2 4 6 8
Click to expand...

What can happen if I use the wrong cable or orient the connector 180 degr. wrong?
 
per said:
Pin 1 is the side whit the odd colored cable (often red/purpelish).
Click to expand...

Encountered a problem...pin 1 wasn't marked at the header as I thought so I have no clue riht now how to orient the cable...or if I can damage something if I orient it wrong :confused:
 
Amigaz said:
What can happen if I use the wrong cable or orient the connector 180 degr. wrong?
Click to expand...

The device you attach it to won't work.

As for blowing things up in a dazzling display of technicolour pyrotechnics, nope, sorry, highly unlikely.

By tradition, the pad for pin 1 is square and all the rest of the pins for the chip/connector are round.
 
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