i had 4 good chips,, and now all i have to work with is chip 5 which i'm hesitant to use at the moment..i have the G2 adapter,,but i'm wondering if my solder job is the problem or if chips were bad to begin with.
was checking continuity between pins to make sure i had no solder bridges etc.
there are 3 pins that all seem to be shorted..i looked up the data sheet for the chip and it looks like pins 2, 26, 27 all seem to be shorted or reading 0 ohms when there installed..are my chips bad? I'm using W27C512-12 chips.
can anyone tell me if this is normal..
My SES light just keeps flashing really really fast..
tried disconnecting the Neg battery term..didnt help.

 

Checking the resistance of ICs with a DVM has the potential to burn stuff out. Avoid doing that in the future. Also keep in mind that there will be ground pins as well, which may appear to be "shorts". The datasheet should indicate teh ground pins.

Now, the fact that the SES is flashing means that the ECM is still somewhat functional. But, its not reading the chips. The flashing is from the checksum failing, and the ECM restarting. How are you programming them? Are you putting the bin in the right place? I dont recall what the offset should be, but I remember having to offset the bins when I was using a home-made chip adapter with my TBI ECM. The bin need to fall in the right place in the address map. Also, are you sure that you didnt pull up any traces? The RN stocket is hard to remove. Might want to also check that the traces are all still intact.

 

I use the SST27SF512 chips and I have a spare Winbond 256 chip and i use offset C000 to program them and have no issues. And yes using a DVOM on your EEPROMS can kill them because of the current from your meter.

 

I've never had a problem checking anything with a DMM,
i can check frequency ,resistance, voltage AC/DC, amperage, and continuity,,a few other features to but i dont have the attaching hardware to use them correctly .
if your using anything other than a DMM then yes you could fry your chip i guess,,but i don't think my DMM did any damage to the chips,,since i only tested the chips after the engine and ecm started messing up.....i'll figure this eventually..for some reason or another whenever knowone seems to have the quick answer i find the solution days afterwards..
thanks for the reply tho you made a good point in warning ppl about there static sensitive proms

 

The resistance mode in DVMs typically use AC to check resistance, and the voltage may be as high as teh supply voltage, which is 9V for many meters that I have. Many GM service manuals explicitly say not to use DVMs to check internal circuitry. Theres not much you can tell with a DVM with ICs, anyway.

Back to the ECM. How did you remove the RN socket? Did you remove it pin by pin? How did you desolder it? As I said before, if your not experienced with soldering and such, they can be hard to remove. Its real easy to pull up a trace as the plating is on both sides of the daughter board.

 

getting the socket off the pcb was easy, since i've done it before..used soldering iron to heat and remove the plastic from around the pins where possible so only the pins themselve were left to tangle with,,then used solder-wik to remove the solder from the pins where possible(refilling holes with new solder helps sometimes) then used vaccum pump(radio snack brand) to clean up the solder from the holes..followed that up by using radio /tv cement solvent to remove all rosin flux from the pcb..and then installing the new socket..took about 20 min to remove it once the plastic was out of the way.
I also use a ESR meter to measure any resistances below the readings of most DMM's ESR- Equivalent series resisance ..main function is testing caps while still in-circuit,but can also be used as low resisance meter for measuring down to .001..do a google search for Dick Smith ESR meter and the manual will explain it's features much better..also has the schematic/parts list in case you want to build your own too :-)

sorry for the long reply delay,,the reply email got sent to the junk folder for some strange reason lol