Precision Analog-to-Digital Converter (ADC) with 8051 Microcontroller and Flash Memory MSC1210Y5... I can't not download the .HEX file!

I use the "TI Downloader" to download the .HEX file to microcontroller MSC1210Y5 more than 5 years and never had problems before. Now, after pressing the "Program Load" and "Reset" as needed and as I always do, start the "TI Downloader" with the hex file I need to download and the following error appears: "No Response to initial CR". The signal on pin 45 (ALE) and pin 44 (PSEN) as it should. Pin 3 (RxD0) receives the initial <CR> "Ti Downloader." Everything seems right, however the download does not start. I think it's a whole lot of that problem in part because I bought last tested four components of this lot and the problem is the same for everyone. The curious thing is that if I replace the last component of a lot by a lot older the problem does not occur, under the hex file and the card works normally. I tried to enable "Erase Hardware Config" in "TI Downloader" and nothing happens. Actually tried everything and I can not solve this problem. I hope someone can help me and I am available to help those in need since it is within my reach. I thank everyone. Thanks!

Julio,

What version number of the TI-Downloader are you using?  What is your crystal frequency?

It sounds like a timing issue to me.  Have you tried any of the other downloader programs?  They can be found in this directory:

ftp://ftp.ti.com/pub/data_acquisition/MSC_CD-ROM/

You mention problems related to a particular lot.  Can you explain more what you mean, and what lot codes work and which one doesn't?

Best regards,
Bob B