T23 mobo with unusual behaviour

[RealBlackStuff]

Got a T23 mobo 26P8218, checked (hopefully all) the fuses, and resoldered all inductors and quartzes, just in case.
Without any RAM it beeps 1-3-3-1 (correctly).
As soon as I put (good tested) RAM in, in either or both slots, the mobo gives 4 short beeps.
I don't see any security chip, nor does it seem to be missing (most T23s don't have it anyway).
There is nothing else attached.
Any suggestions?

[rkawakami]

In all my dealings with T23 systems I don't recall ever getting the four short beeps error code. Nor have I ever had any problems (or experience) with the Secure Chip, even though most of the SXGA+ systems have it. The Secure chip socket is located on the bottom of the motherboard, just opposite of the Y6 crystal. The only things that I can suggest would be to look at the memory slots for any bad solder joints and swap out the CPU with a known good unit.

[RealBlackStuff]

Thanks once again, Ray.
After trying 2 other (working!) CPUs, finally a third CPU did the trick.
It could also be dirt/dust in the CPU socket.
I'll blow it out with compressed air and try the other ones again, just in case.

[rkawakami]

Could also be another microcrack in a solder joint somewhere. After it's back in the case, try flexing the front left corner up and down and see if that has any effect.