https://archivedforum.beoworld.org:443/forums/42.aspxAdvanced Technical Forum for discussion of Bang & Olufsen products at component level.enCommunityServer 2008 SP2 (Build: 31104.93)https://archivedforum.beoworld.org:443/forums/thread/219680.aspxTue, 04 Aug 2009 13:07:14 GMT41a2a90c-3a1e-4bd3-b144-3883695a7f38:219680Die_Bogener0https://archivedforum.beoworld.org:443/forums/thread/219680.aspxhttps://archivedforum.beoworld.org:443/forums/commentrss.aspx?SectionID=42&PostID=219680<p>This is either a timing issue of the communication of the cpu board to the display board or it is a defect MM5450 display driver.</p> <p>The MM5450 display driver chip has some problems with age and overvoltage. Sometimes a defect led causes a shortcut and kills also this chip.</p> <p>The problem is, that this chip is also used for for other controls, not only the display, also to switch on power and some other control functions.</p> <p>The chip can be replaced on the display board, but... it&#39;s very much work to do this 40pin chip on a double layer board.</p> <p>As long as the function itself is ok, there is no need to repair it.</p> <p>I would check wether all display functions are ok and all leds have the same brightness. Some texts use 2 leds in serial, some just 1 led. If there is a difference in brightness or even one text missing, there could be a shortcut by the led. And shortcuts cause an overload of this chip.</p> <p>The display boards of BM5500-6500-7000 are identical and exchancheable. </p> <p>Martin</p><div style="clear:both;"></div>https://archivedforum.beoworld.org:443/forums/thread/219677.aspxTue, 04 Aug 2009 12:08:56 GMT41a2a90c-3a1e-4bd3-b144-3883695a7f38:219677Mdyarnell0https://archivedforum.beoworld.org:443/forums/thread/219677.aspxhttps://archivedforum.beoworld.org:443/forums/commentrss.aspx?SectionID=42&PostID=219677<p>Hi all, I must admit that I am a newby to B&amp;O but as I have read from some of your other posts, it is rather addictive and I find myself in that position now...everything about my new B&amp;O Beomaster 6500 makes me giddy with excitement...my wife says I remind her of a schoolgirl with a crust...I admit that I love it!&nbsp; </p> <p>For all its greatness though, I am having a bit of an issue.&nbsp; For some reason, certain things will trigger the illumination of both the CD and Tape 2 light (at the same time) in addition to the &quot;Timer Off&quot; display.&nbsp; Funcationality doesn&#39;t seem to be affected at all, but something doesn&#39;t seem quite right about it...perhaps it is completely normal under some programming circumstance I am unaware of.&nbsp; After playing with it for a bit here is what I know.&nbsp; I can unplug the unit for 15 minutes or so and then plug it back in and all I get on the front panel of the Beomaster is a small red light (beside where the volume level indicator would be should you adjust the volume), I assume this is the &quot;stand-by&quot; light.&nbsp; If I press the left switch on the Beomaster (step programming) which switches on the radio to a radio preset and then press the mute button on the right side the display illuminates the CD, Tape 2 and Timer Off indicator.&nbsp; Again, no functionality seems to be affected, just the lights come on.&nbsp; Now, if I use the master controll panel to switch the unit off, these three indicators stay on.&nbsp; Only when I uplug the unit for another 20 minutes will these indicators reset back to the simple red &quot;stand-by&quot; dot.</p> <p>I am not sure if this is the only trigger for this result, but figured that one of you might have some insight for me on this issue.&nbsp; I am pretty electronic savvy so could replace a component if I absolutely had to, but the B&amp;O novice in my wonders if this is normal or even an issue I should concern myself too much with if the unit is otherwise working normally.</p> <p>Thoughts, comments, tips or education is very much appreciated!!!</p><div style="clear:both;"></div>