Why does my a6702f not recognize the hdd and dvd but will recognize and load the

I recently was given a Pavilion a6702f tower that the HDD had crapped out in. I replaced the HDD with a new Seagate 250 GB SATA @ 7200rpm.
Done a complete inspection of all the cables, connectors and fittings on the mobo and all looked correct and seated properly.
On power up, it just hung there with no post, no beep, no video and the only sign of activity was the DVD giving out 5 hardly audible ticks. I checked all the voltages with my trusty Power Supply Tester and all was good.
Following your previous advise I disconnected the multi-reader and tried again. I did get to the BIOS Setup screen, hit the F5 to reset to default values, the screen showed that no drives of any type were present even though the DVD and HDD were connected and the drive search was on "Auto". I hit F10 saved and exited. On reboot, it was back to square one with no post, no beep, no video and has remained there even with repeated attempts at a restart. I have also repeatedly tried disconnecting the RTC bty and power cord and holding the power switch in for about 10 sec with no success. I'm not a newbie at this but, it is the first time I have ever encountered this problem. Is this thing fixable or, do I scavenge it for parts and write the whole thing off as a bad experience?
Frank

frankthompson@bell.net