Help! some problems about recording CD-R

I burned two types of CD-R about half a year ago
One Type is
Dye Type 8
The other is
Dye Type 6
when I recorded them at that time,I could use my CD-ROM which had been used for three years to read all of them smoothly

But Now when I use the CDROM to read the first type of CD-Rs(Plasmon) I can hear the CD-ROM maybe start several times (I can hear it rotated and stopped and rotated again for several times) but in the end,It will say There is no CD or Even it recongnized the CD the data transmission is very slow.
but I can use my newly buyed CD burning (BenQ) to read the same CD smoothly.

Regarding the second type CD-R both the CD-ROM and the CD-Burner can read it smoothly now.

So I was confused.

Does the problem lie in the CD-ROM.but It can read the second Type of CD-R

Does the problem lie in the First Type of CD-R but It can be read smoothly by the CD-burner.

And does the problem lie in the Dye Type and somebody told me the problem lies in the CD-ROM’s Laser rate.

Please Help me!! Thank you.

Most probably the CD that cant be easily read suffers from lots of errors and your CD Rom can not do good enough error correction in order to read it, while the recorder can.

So basically it sounds like a combined problem of bad quality media which was badly written / stored and of a drive (CD Rom) with low error correcting capability.

But My condition is not like what you said.
When I read the first Type of CD-Rs using the old CD-ROM ,It did not report the “CRC Error” like the most condition,But it could not recognize the CD-R,just like you did not insert the CD-R into CD-ROM
Also I can read this CD-R in newly buyed Burner accurately No Mistake! NO ERROR.
So What do you think the problem is??
Anyway Thanks for helping me.

Are you checking the CD for C1 & C2 errors using a program like Nero CD speed ?

Because when you say " no error " it sounds like your saying the computer doesn’t give you an error message.

If you begin to experience problems with a disc that used to work fine, it may be beginning to fail. It would be advisable to make a backup copy of the disc if you wish to keep whatever is on it.

I should say again

The problem is not there are some errors when reading the disk,but The CD-ROM can not RECOGNIZE there is disk in the CD-ROM,just like you do not put the disk in.

Although I do not test the CD in nero CD Speed,but I can read the disk in the CD-Burner and the file can run correctly. But In CD-ROM ,It can not be RECOGNIZED ,so It can’t be tested either.

So I think some people say the problem lies in the LASER RATE of the old CD-ROM(I do not know clearly if I Should say LASER RATE)
Maybe they are right,because the problem is very strange.