Sharp LC-32E67U: Whites are yellowish after PWB replacement

[stragulus]

Hi,

I found this TV in the hallway of our building. It turned on but the backlight never came on. I replaced the power supply/inverter board with a brand new one pulled from a tv with a broken screen that I got from ebay. After resetting the error code in the service menu it operates fine.

However, no matter which settings I change, whites appear yellowish. I suspect this may be due to wear of the backlight lamps, but since I have zero previous experience fixing LCD TV's I thought I'd better ask.

I can't find a setting in the service menu that shows how many hours the tv has been turned on. I can however see image burn-in in the bottom left and right corner, which displays date/time and the word 'live' on the right. So I guess this thing has been wall-mounted (there's no stand) in some office with a news/financial channel on all the time.

Would that explain the yellow tint? Changing color temperature, reducing yellow, disabling OCP / dynamic contrast etc etc only have a very minor effect, even on the brightest settings whites are still yellowish.

See the attached pictures; the picture with '8:23' time remaining in it is most representative of what it looks like in real life, the other two are just to show the service menu info and overall color/brightness accuracy.

[selldoor]

Re: Sharp LC-32E67U: Whites are yellowish after PWB replacement

Maybe the tubes are just a bit tired or maybe it has been used in a smoky atmosphere. Whilst it wont fix it, if you disconnect the cables to the tcon the panel will probably light up all white /or yellowish. and will place the problem as being with the back lights
Was the inverter from the same model tv

[stragulus]

Re: Sharp LC-32E67U: Whites are yellowish after PWB replacement

Thanks for your response. If I disconnect the 2 flat ribbon cables from the lcd controller board I get an all black picture with just the backlight on. Disconnecting any of the 2 cables going into the lcd controller will just generate a blinking led error.

The only thing I replaced is the power supply / inverter board with the exact same model ( runtka548wjqz ), everything else is original.

[selldoor]

Re: Sharp LC-32E67U: Whites are yellowish after PWB replacement

Sorry that didnt work - some come up all white perhaps someone will have more ideas.

[stragulus]

Re: Sharp LC-32E67U: Whites are yellowish after PWB replacement

Even with monochrome enabled whites are not white. Maybe yellow is not the right description.. the thing that has the most effect is color temperature. The higher that setting is, the whiter it becomes. But it looks like it would at least 3 more higher settings to actually look white. E.g. maybe it's just too warm (red)? Would that be a sign of wear?