Sony CPD-E220 service manual Safety Related Adjustment, HV Hold

SECTION 3	CPD-E220/E215E/E220E
SAFETY RELATED ADJUSTMENT

When replacing parts shown in the table below, the following operational checks must be performed as a safety precaution against X-ray emissions from the unit.

		Part Replaced ( ] )
HV Regulator	D board	IC502, T501 (FBT)
Circuit
HV HOLD	D board	D538, R521, T501 (FBT)
DOWN Circuit
Beam Current	D board	IC901, R949, T501 (FBT)
Protector Circuit

Allow the unit to warm up for one minute prior to checking the following conditions:

a)HV Regulator Check

1)Input white cross hatch signal. (fH = 69 kHz)

2)CONT maximum and BRT center

3)Cut off Screen VR (G2).

4)Input voltage: 120 ± 2 VAC

5)Confirm that the voltage is within the voltage range

shown below.

Standard voltage: 26.9 KV ± 0.4 KV

6)When replacing components identified by ], make sure to recheck the High Voltage.

7)Verify the High Voltage as shown above (26.9 KV ± 0.4 KV) is within specification. If not, set H. SIZE data at minimum (-127) and then adjust VR501 on "D" Board.

VR501

8)After adjusting the High Voltage within specification, put the VR cover on VR501 as shown below and apply sufficient amount of RTV around VR501.

b)HV Protector Circuit Check

1)Confirm that the voltage between cathode of D517 an GND is more than 27.5 VDC.

2)Using an external DC Power supply, apply the voltage shown below between cathode of D517 on "D" and GND, and confirm that the HV Hold-Down circuit works. (Raster disappears) Apply DC Voltage: Less than 35.8 VDC.

Check Condition
• Input voltage	: 120 ±	2 VAC
• Input signal	: (fH = 69 kHz), White Cross Hatch
• Controls	: CONT (max) & BRT (center)
• B+ Voltage	: 179 ±	3.0 VDC

c)Beam Protector Check (Software logic)

1)Using an external current source, apply < 1.55mA between pin qa of FBT (T501) and GND, and confirm that the raster fades out.

Check Condition
• Input voltage	: 120 ± 2 VAC
• Input signal	: (fH = 69 kHz), White Cross Hatch
• Controls	: CONT (max) & BRT (center)

d)B+ Voltage Check

1)Input white cross hatch (fH = 69 kHz) signal.

2)CONT (max) & BRT (center)

3)Input voltage: 120 ± 2 VAC

Note: Use NF power supply or make sure that distortion factor is 3% or less.

4)Confirm that the voltage is within the voltage range

shown below.

Standard voltage: 179 ± 3.0 VDC

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