Memcal programming problem

[GeorgeM]

I'm having problems programming a VR memcal. The chip is a 014 67633 which I believe is a 27C512. I have erased it using UV and it shows up as empty but when I try to program using a Willem programmer it just keeps giving an error. I have selected the 27C512 as the device and reset all the dip switches and have hit a dead end. In the past I have programmed around 25 of the VN style memcals with the 27C128 chip without problems using the same gear.
Any ideas would be helpfull or even someone around Brisbane that could take it on as a job.

 

[Immortality]

I had similar issues with a Willem programmer using VS ecotec memcals. In the end I found the memcals needed longer under the UV eraser even though they did read as blank. I now use some eucalyptus cleaner to ensure the little window is nice and clean and I changed to a more modern programmer. I also use EEProms when ever possible as it reduces the hassles and problems.

 

[GeorgeM]

I'll give it a double go under the UV and clean the window. I do have an 27SF512 on order but was hoping to get it going over the weekend and it will take a while to get here. Can you recommend a better programmer.

 

[delcowizzid]

Erase for 5-6 minutes and don't blank check I found my William would error if I blank checked before writing.gqx-4 is a good programmer or there' s smaller minipro tl866cs programmer work mint for cheap on ebay

 

[GeorgeM]

I'll give it one more try but I think if I erase to many times I may kill it.
I ordered one of the TL866cs programmers yesterday, should get it next week and hoping the Willem hasn't killed the 27C512 in the mean time.

 

[delcowizzid]

I've erased and programmed some over 100 times should be fine just don' erase to long they hate that.long time since I used the willem you might need to adjust the programming Us speed a bit higher for the 27c512 I used to on some chips

 

[GeorgeM]

Willem settings are
twp 140 us
twc 20 us.
What would you suggest for faster settings?
Also I read somewhere you need the supply voltage to be 6.25 to program. I tried moving the supply jumper for 6.2 volts but the program gives me an error message.

 

[delcowizzid]

Try 280 and 30 see if it verifys after

 

[GeorgeM]

Tried those setting but didn't seem to help. I tried to read the chip after the failed write and it shows up as all FF's in the buffer, almost like nothing is getting in.
May have to wait till new TL866 turns up or I'll end up bald.

 

[delcowizzid]

Sounds like a bad connection to the chip.but what software version is it 97.ja