I picked up this Asus P5A Rev. 1.03 a while back and noticed some missing components after I had been using it a bit. It looks like D7 and D8 have been knocked off.
I haven't noticed any instability on the platform running some games and benchmarks. Does anyone know the function of the circuit these components are on or their part #/value so I can replace them?
It looks like 1N4148 SMD Glass Diodes.
1.05 doesnt have those diodes so its nothing that important 😜
I do have boardview for P5A-B (AT version)
now comparing P5A-B and P5A revisions those three 74 series chips get integrated into one proprietary Asus "AS61256-8"
4 diodes on ATX version are close to those chips, but on AT version they are most likely D1-4 close to ALI chip on the other side https://theretroweb.com/motherboards/s/asus-p5a-b
They are wired directly to RS232 header Ring Indicator (RI) signals, 2 diodes clamp the signal between ground and 3.3V, two others combine it into one common RI . I guess without those two diodes you wont be able to ... host a BBS? 😀
Thank you for the detailed info. Sounds like it won't be much of an issue since I don't intend on using the RS232 ports.
Its not even normal rs232 usage. Its specifically a signal used by modem to signal ringing.
Hah, even more specific of a use case. Understood.
