View Full Version : Slow POST with CD-RW/DVD Combo Drive

23-01-2004, 12:59 AM
A Cyber-Drive CB511D Combo V130A CD-RW/DVD drive was fitted as a replacement for a working (generic) CD-ROM in a 64 MB RAM Gateway G6-400C Celeron 400 Mhz machine using the original Intel RC440BX motherboard and American Megatrends 4R4CBOXA.15A BIOS. This changed the BIOS power-on self test (POST) time from 20 sec to 140 sec for recognition of the original Quantum Fireball HDD followed by immediate recognition of the combo drive and Win98 starting up as normal. The combo drive functioned as expected as a CD-ROM and CD-R drive (not
yet checked as a DVD drive) and there seems no deterioration of HDD performance.

Changing back to the original CD-ROM drive gave the earlier 20 sec POST time.

The only suggestion arising from a WEB search was that the indications are that the power supply (90W, max 1.5 A on +12 V line) might be inadequate. The combo drive and the CD-ROM drive are both rated at 1.5 A max on the +12 V line, and the HDD specs suggest a 0.8 A operating and a 1.9A peak start-up current. Checking the +12 V power line on powering up shows immediate rise to a nominal +15 V and no drop off in voltage throughout the POST and Win98 start-up.

The HDD is the only (master) drive on the primary IDE and the combo drive is the only (master) drive on the secondary IDE. The BIOS is set for auto-detection of IDE drives. The only other peripheral is the PCI modem card. Changing the BIOS setting to recognise only the primary IDE (ie HDD) and still leaving the power connections to the combo drive returns the POST time to about 20 sec.

Have you any suggestions which avoid me having to have coffee every time I start my machine?

Graham L
23-01-2004, 06:01 PM
The new CD might have a higher startup surge... and be dropping all the supplies. I would say that supply is "marginal" (if you might be pulling 0.8A + 1.5A from a 1.5A supply sometimes). It's hard to see some voltage variations (especially with DVMs).

Perhaps the startup surge from the new drive is dropping the Power OK signal (which resets the CPU) a number of times,restarting the POST several times (7 times?) untilthe drive is spinning fast enough that it isn'tpulling a starting current.

If this is happening you might see the KB LEDs flashing several times (instead of once each) during the extended POST.

24-01-2004, 11:10 AM
Thanks Graham.
POST seems to run only once.
Keyboard LED's flash on power-on and again almost immediately as BIOS screen reports (legacy) keyboard detected.

24-01-2004, 01:01 PM
Try changing secondary detection to CDROM and also try with it set to OFF. Some PC's will detect CDROM even though the ide secondary is Off in the Bios.
Don't know if it would work, but it bumps your post up and eliminates another solution.

24-01-2004, 03:33 PM
turn boot from cd rom off in BIOS

29-01-2004, 12:00 PM
Thanks for all suggestions.
I have upgraded from 90 W to 145 W PSU and now have fast POST.
The suggestions re BIOS changes for sec to CD-ROM or off, and disabling boot from CD didn't work in this case.

For me, this thread can now terminate.