View Full Version : hitachi le39h217 lcd tv- ps # ccp-3400st


ronl
03-21-2016, 11:56 AM
Hi Members-my 1st post about repairing newer stuff. i find it difficult to find schematics/service info for the newer flatsceens(i ussaly fixed the board instead of replaceing it in the past). in most cases,if i can get the data,i can troubleshoot and repair boards.
is there a site or 2 that has data for flatscreens like bama's vintage data?
i would like to find the schematic of the power board in this set(used in a few from what i have googled).board # ccp-3400st. even if i had the proper output voltages for the backlite,that would help.backlite outputs through connectors cp7002 and cp7003.

this set was dropping brightness on 1 side after warming up. i confermed it was the power supply by switching the 2 cables going to these connectors and the drop in brightness switched sides.
i went to grab my cold spray to trouble shoot the thermal problem but then the backlite quit.
backlite comes on for a sec when powering up,then goes dark-rest of the set works well.

i did change the 1 cap that was rated at higher voltage(47uf @250v)but no change.

any idea where to get this info or even just a pinout that includes expected voltages?
thanks for reading this.
RonL

Electronic M
03-21-2016, 03:02 PM
You might want to try reading and searching the chip numbers of the regulators etc. You'll learn a lot about voltage specs of a line by tracing it to a regulator and looking up it's datasheet.

miniman82
03-22-2016, 11:22 AM
Sounds like either you need a new backlight board or the lamp is past its prime.

ronl
03-23-2016, 09:50 AM
im hopping it is the power supply since switching the 2 cables resulted in the problem changing sides-points to supply problem and not load side. the set fired up today with orginal problem-works well for about 20 min,then 1 side dims.might try cold spary. im gonna measure each pin when it is working well and if i cant find schematic of power supply,then i might diy a seperate supply for backlites.just wondering if its ac or dc or mixed. should i measure with a dc scope incase there is a signal or just a plain voltmeter?also, im wondering what controls the brighness of these lcd flat panels?is it the brightness of the backlight? how about modern video projectors? is the brightness controlled by bulb brightness?from what i can figure out since a schematic seems rare to find is this is the case. am i correct?
thanks for reading this thread.
RonL

Captainclock
03-31-2016, 09:16 PM
im hopping it is the power supply since switching the 2 cables resulted in the problem changing sides-points to supply problem and not load side. the set fired up today with orginal problem-works well for about 20 min,then 1 side dims.might try cold spary. im gonna measure each pin when it is working well and if i cant find schematic of power supply,then i might diy a seperate supply for backlites.just wondering if its ac or dc or mixed. should i measure with a dc scope incase there is a signal or just a plain voltmeter?also, im wondering what controls the brighness of these lcd flat panels?is it the brightness of the backlight? how about modern video projectors? is the brightness controlled by bulb brightness?from what i can figure out since a schematic seems rare to find is this is the case. am i correct?
thanks for reading this thread.
RonL

Usually the backlights on these LCD TVs use what's called a Cold Cathode Florescent Light (CCFL) and those actually use an inverter to convert the DC Current from the electronics to the AC Current that the bulbs need and if those inverters go out then your CCFLs go out or don't work right because the CCFLs require AC Current to run which is acquired through the inverters, I would check the inverter circuitry first to make sure it hasn't failed.

Findm-Keepm
04-06-2016, 06:24 PM
Folks, first, this is an LED backlight model - no CCFL or inverters. Second, it's made by Orion America for Hitachi - Hitachi has left the TV manufacturing business and is relabeling Orion stuff.

Orion is famous for non-support. HitachiServiceUSA lists only owners manuals and suggests contacting Orion America for service or support.

If it is like most Orion products since 2002, no support is offered beyond replacement remotes. They design the sets to fail, and offer no support.

Your only hope is a donor set that you can swap cards, or troubleshoot blind, without documentation.

Hitachi last produced a set of their own in 2011.

Cheers,