You need to be experienced with the EMS to be able to fully
identify the box as faulty. This is achieved by the backyard mechanic with a lot of reading and hands-on experience with the EMS, or by an experienced AEM EMS tuner that can look at what is being displayed while cranking (via internal logs at a minimum). The EMS will tell you everything you want or need to know and you must possess the ability to extract and interpret the data to effectively troubleshoot a "no-start" condition.
Fuel and spark are dependant on cam/crank synchronization, and I have not seen an instance where both are dead UNLESS there is no "stat sync". If you do not know what "stat sync" is then it is time to hit the books, or find a competent AEM tuner; Period. If you attack the EMS blindly you will be very very disappointed.
Usually coil drivers go bad by someone using a MSD/Grantelli (sp)/et al coil pack (other than stock) which puts too much of a load on the drivers and eventually fries them.
The easiest way to tell if the injectors are firing is to hook up a noid light to the injector pigtail and attempt to start the car. At a minimum you should see 1 brief pulse which is the initial crank pulse.
Here is a quote from AEM which describes it much better (source: http://aemelectronics.com/?q=forum/c...al-crank-pulse
"The EMS will never fire coils or injectors unless Stat Sync is ON. That's rule #1
. Crank Inject All simply fires all the injectors at the same time when the Initial Crank Pulse fuel is delivered. Initial Crank Pulse is the first "squirt" of fuel that gets delivered during starting which is then followed by Crank Injector Time. When Crank Inject All is OFF, the Initial Crank Pulse is delivered sequentially. "
I must warn you that no 2 cars are alike and getting the EMS to "fire" with a stock canned tune will not always work. For instance my car had a crap tune on it when I purchased it. I rescaled the "stock" tune to match my fuel pressure and injectors and it would never sync cam and crank (stat sync). I took the crap tune settings that dealt with the timing sequence, merged it into the stock/rescaled tune, and it fired right up.
From a distant internet armchair quarterback perspective I willing to bet that the person that you sold the EMS to had no clue what they were doing.