Hi!

I've got a working hybrid Slot 1/ PGA 370 motherboard, the Jetway J-9BXAN (or BN700, as marked in my case).

Apparently, it does not support FC-PGA processors out of the box. However, a later revision of the manual refers to a certain JP11 jumper to switch between PGA Celerons and FC-PGA Coppermines. In my board the jumper wasn't installed, but a solid wire between positions 1 and 2. I obviously went ahead and soldered a proper 3-positions jumper header. I give it a try and neither of my 2 Coppermines work. The PCI debug card shows "--" and eventually a siren-like sound comes out of the PC speaker.

Note that both coppermines work when paired with a Slotkey adapter regardless of the setting of this JP11 jumper. A PGA Celeron 300A also works when inserted in the motherboard's 370 socket.

I've been digging for more information on how to make the socket work with coppermines and the only useful resource I did find was this article on an Abit ZX board as well as the THG article it was based on.

So ... I proceeded and installed two wires (one for the AH4 pin and the other for X4) and an additional jumper header to enable/disable this mod.

In order to isolate pin AM2 from ground I tried covering the CPU pin with UV solder mask (which didn't stick to the pin) as well as covering the socket pin/contact with kapton tape (to no avail). I ended up desoldering one of my Coppermines' AM2 pin. Unfortunately, it still does not work.

I've tried measuring with a multimeter if JP11 has any effect on the AM2, X4, AH4, E27 or S35 pins but it does nothing. It seems to be some sort of hard switch between 2 groups of resistors and resistor arrays to either side of the jumper. "If coppermine then use the resistors to the right, otherwise use the ones to the left". I haven't found where does the output go to, but I think it does affect at least the VRM controller: if I power on the board with no processor at all and JP11 in the Celeron PGA position, I'm measuring 2 volts from the mosfets. When JP11 is in the Coppermine position, I measure around 1.56 volts. Note that inserting a CPU will override this behaviour and use whatever voltage it is designed to be powered by.

Whilst I can already run Coppermines in this board using the slotkey, I don't plan to keep it (at least paired with this board). I simply bought it to test if the board and my CPUs are working properly. This is now more of a challenge.

Is there anything else I could have a look at? What am I missing? I have the feeling I'm almost there and there's only a single stupid thing preventing the board from working... Thanks for your help!