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Need advice with this mystery

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Full Member level 3
Feb 17, 2004
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I have a XYZ control PCB which controls 5 servo motors and a RF generator (via a rs232 port on the PCB) using a z80180 (Zilog) microcontroller along with a 29F010 flash and a PAL16V8 chip. Servo motors are controlling ok but commands not going to RF generator to turn it on. I checked RF generator using HyperTerminal and com2 and it is OK. The problem is PCB not sending commands to RF generator.

I ordered a new PCB and replaced 29F010 flash and PAL16v8 and surprisingly problem is still there. There was no problem with reading flash and 16v8 content using all-11 programmer and rewriting a new flash and new 16v8 chips and replacing them in the PCB but still problem is there. No commands is going from PCB to RF generator waht so ever. This simple problem is turning to a mystery for me.

I have decided to use dz80 assembler and try to analyse if something might have gone wrong with the flash and 16v8 content. Some people say if you were able to read their content they should be ok and problem is somewhere else. But with a new PCB and working RF generator the only thing left suspicious is this two chips content.

Any advice or comment is welcom. If anyone is interested I can email schematic of the PCB to him to analyse and see if he can help in solving this mystery.



Hi Steve,

Have you received new FLASH and PAL with the new board?
Reading out the contents from PAL migh give you wrong resulting file, PAL's can be "locked" you know :)
Also if you have a corrupted FLASH, there is no sense for it to work on new board, you'll still have same problem.

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