15.32—Test procedures for CPU boards and computer power supplies.
Power supplies and CPU boards used with personal computers and for which separate authorizations are required to be obtained shall be tested as follows:
(1)
Testing for radiated emissions shall be performed with the CPU board installed in a typical enclosure but with the enclosure's cover removed so that the internal circuitry is exposed at the top and on at least two sides. Additional components, including a power supply, peripheral devices, and subassemblies, shall be added, as needed, to result in a complete personal computer system. If the oscillator and the microprocessor circuits are contained on separate circuit boards, both boards, typical of the combination that would normally be employed, must be used in the test. Testing shall be in accordance with the procedures specified in § 15.31.
(i)
Under these test conditions, the system under test shall not exceed the radiated emission limits specified in § 15.109 by more than 6 dB. Emissions greater than 6 dB that can be identified and documented to originate from a component(s) other than the CPU board being tested, may be dismissed.
(ii)
Unless the test in paragraph (a)(1)(i) of this section demonstrates compliance with the limits in § 15.109, a second test shall be performed using the same configuration described above but with the cover installed on the enclosure. Testing shall be in accordance with the procedures specified in § 15.31. Under these test conditions, the system under test shall not exceed the radiated emission limits specified in § 15.109.
(2)
In lieu of the procedure in (a)(1) of this section, CPU boards may be tested to demonstrate compliance with the limits in § 15.109 using a specified enclosure with the cover installed. Testing for radiated emissions shall be performed with the CPU board installed in a typical system configuration. Additional components, including a power supply, peripheral devices, and subassemblies, shall be added, as needed, to result in a complete personal computer system. If the oscillator and the microprocessor circuits are contained on separate circuit boards, both boards, typical of the combination that would normally be employed, must be used in the test. Testing shall be in accordance with the procedures specified in § 15.31. Under this procedure, CPU boards that comply with the limits in § 15.109 must be marketed together with the specific enclosure used for the test.
(3)
The test demonstrating compliance with the AC power line conducted limits specified in § 15.107 shall be performed in accordance with the procedures specified in § 15.31 using an enclosure, peripherals, power supply and subassemblies that are typical of the type with which the CPU board under test would normally be employed.
(b)
The power supply shall be tested installed in an enclosure that is typical of the type within which it would normally be installed. Additional components, including peripheral devices, a CPU board, and subassemblies, shall be added, as needed, to result in a complete personal computer system. Testing shall be in accordance with the procedures specified in § 15.31 and must demonstrate compliance with all of the standards contained in this part.
[61 FR 31048, June 19, 1996, as amended at 62 FR 41881, Aug. 4, 1997]