lwinter
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Dec 27, 2007, 8:08 PM
Post #2 of 5
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Re: [willwatsonfl] Pioneer SD-P5181-K Picture loss after warm up
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Hey there:
I just joined the forum today and happened across your posting. I have a SD-P6081-K, which is simply a bit larger version of your unit, otherwise they're almost identical. I had a similar issue with my unit about a year ago. What was causing my problem and what could be the source of your issue is a cold solder connection somewhere on the under side of the board. Although that line of Pioneers was of really high quality in general, they did have a recurring issue with soldered connections on the boards being poorly made. That resulted in connections developing microscopic breaks over time that often caused intermittent symptoms to appear; one minute the unit seemed fine, the next it was behaving oddly. The symptoms sometimes appear when the set is turned on and then go away after things have warmed up; other times the set will function properly only until the components have warmed up, and then it goes haywire. Thermal expansion of the boards/components/connections appears to be the most agreed upon cause for this.
I fixed the problem on mine by removing the board the flyback is mounted on so that I had access to the underside of the board. After thoroughly cleaning the board with PCB cleaner, I carefully resoldered every connection with a low wattage iron, checking each under a bright lamp and magnifier before moving on to the next. In looking at each of the connections before and after reflowing the solder, I noticed several that looked "iffy" before I hit them.
Once I went through all the connections I went back and rechecked my work, and then put the board back in, reassembled everything and tested the set. It worked perfectly! No more flaking out after an hour or so of use. That was back in Jan '07 and the set hasn't missed a beat since.
The reason I went through the pain of resoldering the connections is that I found the same problem on the convergence board when the STK4277-SL IC went bad. I replaced the chip, which corrected some of the problems, but I still had intermittent issues that would just go away after the set had been on for about 2 hours. I remembered reading about the cold solder problem with Pioneers, so I pulled the board again and reflowed every single connection. When I put it all back together; no more problems.
I'm not a TV repairman by trade, but I am an electrical engineer, so I guess I have some qualification in recommending this (potential) fix, aside from the obvious real-world experience I have with this set. The next time I have a problem with it, especially if it's intermittent or comes on suddenly, the first thing I'll suspect is a solder connection somewhere else I haven't touched yet (which isn't very many left!). Hopefully my set will hang on another year or so; once the conversion to digital signals is completed and the rush to buy new flat panels is over, prices on them should drop even more, not to mention that the picture quality will do nothing but improve as the technology matures and advances. :) Bet my next set is not only far superior to this one, but it'll probably cost less too!
I hope this helps!
Len
PS: Where did you run across the PDF of the SM? I haven't seen that anywhere online and have been looking for one.
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