Checking For Component Damage; Y Ipm(Ic18) Or Z Ipm(Ic2) Damage; Fet Ass'y(Y B/D : Hs2) Damage - HP PL4260N Service Manual

3. Checking for Component Damage

3-1. Y IPM(IC18) or Z IPM(IC2) Damage

(1) When the internal Sustain FET or ER FET of Y B/D
IPM(IC18) or Z B/D IPM(IC2) is damaged, screen doesn't
be shown or Mis - discharge of partial screen is generated.
Test Point : Enlarge after measuring
GND ~ Waveform(Y DRV B/D),
GND ~ B28(Z B/D).
Wave format : Y DRV B/D in Waveform or B28(Z B/D)
has no output wave.
<Fig. 1 IPM Normal Output Wave>

3-2. FET Ass'y(Y B/D : HS2) Damage

(1) When Set_Up FET(2nd FFT of HS2 ) is damaged, screen
doesn't be shown.
Test Point : Enlarge after measuring
O
GND ~ Waveform(Y DRV B/D)
Wave format : As shown fig. 2
O
Set up waveform
does not come out
<Fig. 2 When the Set_Up FET is damaged>
(2) When Set_Down FET/Pass_Top FET(1st, 3rd, 4th, 5th
FFT of HS2 ) is damaged, Mis - discharge of entire screen
is generated.
Test Point : Enlarge after measuring
O
GND ~ Waveform(Y DRV B/D)
Wave format : As shown fig. 3
O
Set up waveform
does not come out
<Fig. 3 When the Set_Down FET is damaged>