ACCRUED LIABILITIES (Details) - USD ($)	12 Months Ended
	Apr. 30, 2018	Apr. 30, 2017
Employee related expenses:
Accrued payroll	$ 167,000	$ 68,000
Accrued payroll taxes	13,000	5,000
Accrued employee benefits	129,000	136,000
Total employee related expenses	309,000	209,000
Other, including interest:
Warranty reserve	300,000	24,000
Property taxes	18,000	20,000
Deferred rent	129,000	7,000
Other	61,000	59,000
Total other	508,000	110,000
Total accrued liabilities	817,000	319,000
Changes in warranty reserve
Balance, May 1	24,000	67,000
Credit memos issued	(52,000)	(161,000)
Provision for warranty accrual	328,000	118,000
Balance, April 30	$ 300,000	$ 24,000