Problem with 'new' CPU (AMD K6-266)

Sean Fox · 9 Jan 2020 at 19:14

I'm really hoping I might be able to pick your collective brains here!

So my new processor arrived today, an AMD K6-266 AFR (regular Socket 7)

However after installing it, all I'm getting is a black screen and "no signal" on the monitor. Swapping the old CPU back works perfectly, so I'm not sure what the problem could be. The seller assured me he had tested the CPU before shipping and it was perfect.

There are no real markings on my motherboard to identify it, other than a few numbers -

It says E139761 along the top edge, and a white socket with: 3M1X2YY 9709. A Google search didn't turn up much meaningful info.

It's a Gateway 2000 system with an AMIBIOS version of 1.00.07.DQ0T UAV

Could it be that the motherboard/BIOS is not compatible with AMD chips? The working processor that I removed was a Pentium 200MMX, and as I say this works fine if I swap it back in.

Any advice you can throw my way would be really appreciated!

paradigm · 9 Jan 2020 at 19:30

Are there jumpers on the motherboard for CPU multiplier and BUS speed? Possibly core voltage also?

Sean Fox · 9 Jan 2020 at 19:33

paradigm said:
Are there jumpers on the motherboard for CPU multiplier and BUS speed? Possibly core voltage also?

Oooh that's a good question, I haven't checked - mind you, I've no idea how they should be set if there are!!

I'll take a look

paradigm · 9 Jan 2020 at 20:12

I do hope that you’ve not killed the K6, from memory they ran a lower vcore than the Pentium MMX.

I think they could run a higher I/O voltage though.

LewisRaz · 9 Jan 2020 at 20:17

100% the jumper settings will need to be changed. Is there no guides on the motherboard itself?

Deleted member 77746 · 9 Jan 2020 at 22:33

Damn! CPU Dip switches! How I remember those well!

sideways14a · 9 Jan 2020 at 22:36

Was it not those early K6s that had no thermal protection on them?
I mind melting the solder out from a Celly P2 slot processor back in the day, totally deliberate mind you as i had fiddled with the jumpers and taped over some of the slot pins to dump even more voltage through it.

Sean Fox · 9 Jan 2020 at 22:50

LewisRaz said:
100% the jumper settings will need to be changed. Is there no guides on the motherboard itself?

Nothing that makes any sense to me - I took a few gut shots this evening - as you can see, there aren't many jumpers, and the ones that are there aren't really labelled

Pics here: http://imgur.com/a/awpcOfx

sideways14a · 9 Jan 2020 at 22:58

To be honest, if its that old then its likely all the transistor gates have seized up.
You can get special stuff from the rainforest to put into your old old box to free them off and release the magic smoke.

LewisRaz · 9 Jan 2020 at 22:59

Sean Fox said:
Nothing that makes any sense to me - I took a few gut shots this evening - as you can see, there aren't many jumpers, and the ones that are there aren't really labelled

Pics here: http://imgur.com/a/awpcOfx

On the last screenshot you can see at the top left there is a box with "bus freq" and a list of variations.

You will need to set the bu freq to 66 and multi to 4x.

Although looking at that it only goes to 3x so its possible you cannot run that cpu at 266 on there.

Sean Fox · 9 Jan 2020 at 23:03

LewisRaz said:
On the last screenshot you can see at the top left there is a box with "bus freq" and a list of variations.

You will need to set the bu freq to 66 and multi to 4x.

Although looking at that it only goes to 3x so its possible you cannot run that cpu at 266 on there.

Damn! I completely missed that!! Thanks for the advice! Am I likely to damage anything if I can only set the multiplier to 3x?

Something's telling me a newer motherboard might just be the best way forward...

Edit - thinking about it, there's no point me running it at 66 with a 3x multiplier anyway since my working CPU is already 200mhz. I guess I'm kinda stuck!

LewisRaz · 9 Jan 2020 at 23:09

Sean Fox said:
Damn! I completely missed that!! Thanks for the advice! Am I likely to damage anything if I can only set the multiplier to 3x?

Something's telling me a newer motherboard might just be the best way forward...

You would not damage anything running a cpu slower than intended. You will need to see if there are any voltage jumpers on the board as that is where the damage is possible. Socket 7 motherboards really bridged the gap between AT and older style configs and ATX with more modern and familiar set ups. Your one appears to sit somewhere in the middle (a lot of onboard i/o compared to early ones!).

sideways14a · 9 Jan 2020 at 23:10

Sean Fox said:
Something's telling me a newer motherboard might just be the best way forward...

Dude this thing is older than many of my students, i wouldnt be wasting my time trying to get it to work now let alone find another main board for it.

Sean Fox · 9 Jan 2020 at 23:40

sideways14a said:
Dude this thing is older than many of my students, i wouldnt be wasting my time trying to get it to work now let alone find another main board for it.

I see what you're saying, but this really isn't a waste of time for me - there are a whole bunch of games that simply don't function well on modern hardware which is why I'm keen on maintaining an old system.

Deleted member 77746 · 9 Jan 2020 at 23:42

It’s not dip switches is it by looks of things it’s pin headers!

paradigm · 10 Jan 2020 at 10:29

So I did a little research to double check if I was right about vcore. Pentium 200 MMX is rated for 2.7-2.9v. The K6-266 is only rated for 2.1-2.3.

If that board isn’t automatically changing vcore (which I HIGHLY doubt for the vintage), there is a distinctive possibility that the AMD chip may have been overvolted and died. You might get lucky in that you only had it powered on for a short time, but that doesn’t bode well.

Duke · 14 Jan 2020 at 19:36

Agree with the above, there will be jumpers for voltage although from the photo it doesn't give a table so would have been on a manual or a sticker inside the original case instead to show the settings needed.

Sean Fox · 15 Jan 2020 at 11:09

Duke said:
Agree with the above, there will be jumpers for voltage although from the photo it doesn't give a table so would have been on a manual or a sticker inside the original case instead to show the settings needed.

No stickers inside, and none of the jumpers are labelled as being for voltage unfortunately

Annoyingly, I haven't been able to track down a manual for this motherboard.

paradigm · 15 Jan 2020 at 12:06

Have you got a high-resolution image of the whole board (remove all add-in cards, so as to get a good view)?

Might be easier to identify from a non compressed full image.

Sean Fox · 15 Jan 2020 at 12:12

paradigm said:
Have you got a high-resolution image of the whole board (remove all add-in cards, so as to get a good view)?

Might be easier to identify from a non compressed full image.

I don't currently, but I'll try and grab a decent full image with everything removed tonight

Thanks @paradigm !