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Sziasztok! Van nekem egy HP 1702 LCD-ém és egy fázis megszakítás után a monitor 400V 150 mikrós kondi szét nyílt mint a tavirózsa kicseréltem egy új kondira és akkor a monitor tökéletesem működött ,egy 2 másodpercig ,mert a monitor háttérvilágítása azt produkálja, hogy elmegy visszajön de a kép az nem változik az tökéletes ,csak a háttérvilágítás hullámzik, és nem tudom ,hogy mi okozhatja nála. Ha van valakinek valami ötlete, vagy találkozott már ilyen hibával akkor jelezzen már nekem. Előre is köszi a segítséget. Üdv!

Hello all, I'm hoping one of you all here could give me some advice on my dead LCD monitor. First off, let me say, great site! Without it, I wouldn't have been able to even begin diagnosing my monitor, I found the service manual for it here. Hope to be coming back many times in the future! Now the details: The LCD I have is an HP LP2475W 24" LCD computer monitor 1920x1200. I was using it a while back, and then it just turned off. No picture, no power light, even the built-in USB hub had shut off. It's as if someone pulled the plug out, no smoke, noise or anything. I've left it unplugged for a while, and plugged it back in, still nothing. It's almost as if a fuse is blown, though if I listen very carefully I can hear the power supply 'ticking' very very softly. I just bought the monitor factory refurbished by HP in 2009, only has about 6500 hours on it; I expected it to last much longer than this. :weep: Before I spend several days troubleshooting it, I'm hoping someone could give me some guidance as to what usually tends to be the defective component(s). :smiley: - I opened it up and checked it out, and the problem seems to be the power supply board is dead; no output to the main, or 'scaler' board, whether or not it's hooked up to the power supply board. Would this be typical of some faulty electrolytic capacitors, or is it likely to be a more serious problem? I don't see anything obvious, no bulging caps, no burnt parts, nothing. The circuit seems to be a standard switching supply, which sends the 120v power first through a charge pump, which raises the voltage to around 400v. It then goes into a switchmode transformer to create 5v, 12v and 24v to run the scaler board and inverter. Upon checking further, the main 300-400v bus seems to be at only 170v, indicating the charge pump is not functioning or starting. The 120v in and charge pump diode check ok. The problem seems to be in the charge pump control IC (FAN7529 PFC Controller) or circuitry. The FAN7529 chip seems to be getting only about 0.5v on it's power lead, could this be due to it's own supply, or more likely the chip itself? - On the other hand, it may be more economical to replace the power board, HP gives me the following part numbers: ADPC72411AA5 ----- POWER BOARD ADPC G2956-I-X-X-1-080520 (power board assembly number) 715T2956 1 ----------- POWER BOARD PCB (pcb number, sometimes used as assembly number) When I do a Google search, the only places I find that maybe have something like this is China or Poland. Would any of you know where can I could obtain another one of these power boards? - Here are the links to the Service Manual and Disassembly Guide here on ElektroTanya. Shows the Power Supply schematic and color pictures respectively: http://elektrotanya.com/hp_lp2475w_lcd_monitor_sm.pdf/download.html http://elektrotanya.com/hp_lp2475w_lcd_monitor_disassembly_guide.pdf/download.html Also a new version of the schematic that my Dad and I cleaned up, much easier to follow logically: http://elektrotanya.com/hp_lp2475w_lcd_power_supply_schematic.zip/download.html I've also included some detailed pictures of my Power Supply board, hope they help out. - Any thoughts you might have I'd appreciate very much :super: Cheers! :D Robert Ontario, Canada

Sziasztok! Van egy HP 1955 típusú monitorom. Tele volt púpos kondikkal, azok cserélve lettek. A monitor most már viszonylag jól működik. Viszont bekapcsoláskor teszt üzemmódban van, vga jelkor eltűnik és szépen megy. Viszont a táp részéből hangos zizegő hang jön. Mitől lehet ez? Köszönöm.

Sziasztok! A fent említett monitor Kb 2sec. után sötét lesz, akép megmarad rajta. A tápok / kondik/ jók az inverter áll le. Bármilyen ötlet, segítség jól jönne. Kösz.: Laci