Table Of Contents - HP VF15 Service Manual

1) Circuit
1. Power board operation therory ---------------------------------------------------------------------------------------------- 3
2. Inverter -------------------------------------------------------------------------------------------------------------------------- 4
3. Power supply ------------------------------------------------------------------------------------------------------------------- 5
4. On-screen circuit--------------------------------------------------------------------------------------------------------------- 5
5. Video input circuit ------------------------------------------------------------------------------------------------------------- 5
6. Definition converter LSI peripheral circuit --------------------------------------------------------------------------------- 5
7. System reset, LED control circuit -------------------------------------------------------------------------------------------- 5
2
8. E PROM for PNP --------------------------------------------------------------------------------------------------------------- 6
2
9. E PROM ------------------------------------------------------------------------------------------------------------------------- 6
10. CPU circuit ---------------------------------------------------------------------------------------------------------------------- 6
10.1 Dection of POWER switch status ------------------------------------------------------------------------------------- 6
10.2 Display mode identification -------------------------------------------------------------------------------------------- 6
10.3 User control --------------------------------------------------------------------------------------------------------------- 7
10.4 Control of identification converter LSI (IC306) ---------------------------------------------------------------------- 8
10.5 Power ON sequence ----------------------------------------------------------------------------------------------------- 9
10.6 Power OFF sequence -------------------------------------------------------------------------------------------------- 10
11. Audio Circuit ----------------------------------------------------------------------------------------------------------------- 11
2) Trouble shooting
1. No display of screen (Screen is black, color of LED is amber) -------------------------------------------------------- 12
2. Nothing displays on screen (Screen is black, color of LED is green) ------------------------------------------------ 13
3. Checking the back light unit ----------------------------------------------------------------------------------------------- 16
4. Abnormal screen------------------------------------------------------------------------------------------------------------- 17
5. No OSD display -------------------------------------------------------------------------------------------------------------- 18
6. Abnormal plug and play operation --------------------------------------------------------------------------------------- 19
7. Checking the interface circuit of sync signal ---------------------------------------------------------------------------- 20
7.1 Checking the control circuit of horizontal sync pulse ------------------------------------------------------------- 20
7.2 Checking the control circuit of vertical sync pulse ---------------------------------------------------------------- 20
vf15 / FP15 / f1523 / FP5315
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