Hitachi 19LD2550B no picture or sound

[teaboy]

Hi I have an Hitachi 19LD2550B which has no backlight.The TV will turn on and the backlight comes on for a second before going off again. The PSU is a Vestel 17IPS02-2 which I changed all of the 12pf 3KV caps for the backlight which didn't fix it. I've seen a posting on here suggesting connecting pin one of the FAN7311 controller with a 1k resistor which I plan to try next but is this tied to GND or VSS ?

Although there is no sound you can hear the speakers pop on power up and off, would expect to hear the usual tuning hiss white noise but nothing.

Thanks for any help suggestions.

[teaboy]

Hi all - Update on this one.

I've since checked the PSU rails which both look ok, 5v standby and 12v kicks in when TV turned on so both look good. The backlight does come on for approx 1 second after power on but then goes off. Does this mean the backlight inverter is OK ? or is it starting but then shutting off due to a problem with the tubes ? I believe there are 2 back light tubes so I've not had the back off completely to see if both are working. Could one of them have failed this is causing this problem ? When the TV comes on you get the analogue picture of an untuned station (white noise snow etc)

The main TV board is another vestel effort 17MB24H-2 which I'm wondering if this could be at fault as there is no sound, however the backlight signal from this looks correct. All fuses look ok and no bulging caps. Does anyone know if I should get the usual white noise sound when the tv is untuned or does the tv mute this until it gets a station ?

Any ideas guys? likewise any service manuals for the above would be a great help.

Cheers

Andrew



 

[Turnip]

Hi T/B,

Feel there is a tendancy with IPS Power/Inverters to crap their CCFLs - Pin 1 - 1k to deck - gives a few more weeks 'till repair guarantee expires - might be wrong, but - Chris