Sorry for posting in English but there are some good opinions in here!
I'd recently posted for sale a rare 755CDV but with an odd problem whereby when you connect it's CD-ROM drive, it won't power on. Obviously one key feature of the 755CDV besides it's detachable display is the fact it's the joint-first laptop ever with a built-in CD-ROM drive (the 755CD being the first). So I set about trying to work out why, or at least a pattern.
tried the drive in another 755CD and it did the same - no POST. So I first thought 'its the drive' that's the problem, not the machine.
So I took out the (working) CD-ROM drive in the 755CD and put that in the 755CDV and it also had the same symptoms as before - would not POST.
So at this point, I try not to make the mistake many do whereby they do not adapt their thoughts away from 'single problem' mentality. I feel I've probably got two problems. The issue follows the 1st CD-ROM drive, so it's that and that the 755CDV also will not accept any known good CD-ROM drive.
I tried an ultrabay floppy in both machines and they both work fine.
I tried removing the HDD (which would likely be on the same IDE bus) and it didn't make any difference.
I checked the Systemboard type and BIOS - I've upgraded all my 755 machines up to the latest BIOS and the problem is exactly the same on all System boards (P75 and DX4-100), all running latest BIOS.
There are two subtle differences when a machine won't POST. Sometimes I get a long, solid beep - which is an unusual fault alert with a Thinkpad 755, not one I've come across before. And the second 'not-posting' issue is just nothing comes on the screen. No sound, the machine is powered up and even will spin up the HDD and blink the LEDs normally, but nothing ever appears.
Before I downed tools for the day, I built on a bench a 486 DX-4-100 with an identical hardware setup to the 755CDV using a spare system board I had and spare 755CD daughterboards and it accepts *all* the CD-ROM drives!!
So I think I have a CD-ROM drive which is picky as to what it will run on, and some system boards which simply will not accept a CD-ROM drive in the ultrabay.
I still have some further troubleshooting to do but I wondered has anyone else had any memories or experiences with issues using an ultrabay CD-ROM drive on the 755-enhanced models?
My final thought is that despite all 755-enhanced system boards having the same part number and being interchangable, perhaps they are not if your chassis is expecting CD-ROM compatibility. (IBM offered an upgrade of the same system board from 486 to Pentium by swapping out the memory and the CPU complex) . If the 755CD and CDV from the factory are the only 755 machines which will accept an ultrabay CD-ROM drive, it would be extremely odd and curious but seeing as they were bleeding edge, theoretically plausible.
All the best
I'd recently posted for sale a rare 755CDV but with an odd problem whereby when you connect it's CD-ROM drive, it won't power on. Obviously one key feature of the 755CDV besides it's detachable display is the fact it's the joint-first laptop ever with a built-in CD-ROM drive (the 755CD being the first). So I set about trying to work out why, or at least a pattern.
tried the drive in another 755CD and it did the same - no POST. So I first thought 'its the drive' that's the problem, not the machine.
So I took out the (working) CD-ROM drive in the 755CD and put that in the 755CDV and it also had the same symptoms as before - would not POST.
So at this point, I try not to make the mistake many do whereby they do not adapt their thoughts away from 'single problem' mentality. I feel I've probably got two problems. The issue follows the 1st CD-ROM drive, so it's that and that the 755CDV also will not accept any known good CD-ROM drive.
I tried an ultrabay floppy in both machines and they both work fine.
I tried removing the HDD (which would likely be on the same IDE bus) and it didn't make any difference.
I checked the Systemboard type and BIOS - I've upgraded all my 755 machines up to the latest BIOS and the problem is exactly the same on all System boards (P75 and DX4-100), all running latest BIOS.
There are two subtle differences when a machine won't POST. Sometimes I get a long, solid beep - which is an unusual fault alert with a Thinkpad 755, not one I've come across before. And the second 'not-posting' issue is just nothing comes on the screen. No sound, the machine is powered up and even will spin up the HDD and blink the LEDs normally, but nothing ever appears.
Before I downed tools for the day, I built on a bench a 486 DX-4-100 with an identical hardware setup to the 755CDV using a spare system board I had and spare 755CD daughterboards and it accepts *all* the CD-ROM drives!!
So I think I have a CD-ROM drive which is picky as to what it will run on, and some system boards which simply will not accept a CD-ROM drive in the ultrabay.
I still have some further troubleshooting to do but I wondered has anyone else had any memories or experiences with issues using an ultrabay CD-ROM drive on the 755-enhanced models?
My final thought is that despite all 755-enhanced system boards having the same part number and being interchangable, perhaps they are not if your chassis is expecting CD-ROM compatibility. (IBM offered an upgrade of the same system board from 486 to Pentium by swapping out the memory and the CPU complex) . If the 755CD and CDV from the factory are the only 755 machines which will accept an ultrabay CD-ROM drive, it would be extremely odd and curious but seeing as they were bleeding edge, theoretically plausible.
All the best
