Recently, I replaced my dLp chip (Samsung RPTV) because of the white dots that had begun to appear on screen. I continued to use the receiver as the dots increased. Finally, I decided to investigate repairing the receiver. I found an excellent Youtube video dealing with just the issue I had (on screen white dots) but for a different brand receiver.
After reviewing the video, it seemed that most all the rear projection receivers use a similar layout. The difference is the light engine. My Samsung uses three high power LEDs instead of a color wheel and short arc lamp light source.
A precision optical bench provides the video through a series of mirrors and lenses with the picture eventually projected onto a plastic screen from the rear, hence RPTV, (rear projection television).
As of May 2015, I am not aware of any RPTVs currently offered for retail. Pity. These receivers are and were high performers with excellent contrast ratios and color saturation. There are however projectors that still use the TI dLp chipset. The dLp technology is used in a wide array of applications from cell phones to IMAX projectors.
After replacing the dLp component on the DMD board, The receiver worked like new and the dots are gone. The failure of the original dLp component was likely due to excess heat from the dust and dirt that accumulated normally inside the cabinet of a TV receiver. Whenever you are inside the cabinet of a modern TV receiver, it is best to clean dust and dirt from boards and other components like fans and cooling ducts.
After replacing the dLp component for my Samsung RPTV receiver, I ordered the technical service manual from Samsung. It comes on a nice thumb drive available at samsungparts.com. The cost was $12.00. It is 146 pages (30.1MB, .PDF format) and contains everything you need to know to realign your TV receiver to factory specifications. My Samsung required only one alignment procedure after I installed the new dLp chip.
If you do repair your RPTV, I suggest you order this service manual. There is considerable information therein for the novice and professional service technician alike.
