Text preview for : Fujitsu P42HHA10AS Repair tip.pdf part of Fujitsu P42Hxxxxxx Repair tip - Fujitsu P42 inch Random shutdown, Front Panel continous flashing red led
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Fujitsu P42HHA10AS
Repair 21/08/2009 For information:I have recently fixed my P42HHA10AS 42" plasma which had a similar problem. Would run ok for periods, (sometimes 30 mins, sometimes 2+ hours), picture perfect. Then it would randomly fail - with loss of picture, then shutdown. Front panel led indicator goes from green (normal) to flashing red continuous. After switch off, removal and re-application of power it would often re-start and run normally for a while. Sometimes it needed to be allowed overnight to cool before it would run again. I also noticed that the failures generally coincided with any change to the screen display mode or input mode settings. Fujitsu service supplied service manual and Service Bulletins regarding this problem : Service Manual P42HHA10 is available at http://www.eserviceinfo.com/download.php?fileid=41950 Service Bulletin PDP 0040-01 Main Digital pcb see http://www.eserviceinfo.com/download.php?fileid=43455 Service Bulletin PDP 0068-01 Main Digital pcb see http://www.eserviceinfo.com/download.php?fileid=43450 Service Bulletin PDP 0035-06 Main Power pcb see http://www.eserviceinfo.com/download.php?fileid=43471 Worked through the service manual checks (service manual very basic- overview / DC voltages only assumes availability of replacement modules). The troubleshooting flow charts lead you nowhere helpful. Could find no fault with the power board, except that the 6.5V(nominal) was actually 7.4V at CN351 Pin12. Added 2x Schottky diodes (1Watt) in series with the transformer 6.5V output winding - this lowered the output voltage to 6.6V. - However, this made no difference to the continuing fault condition. This units problem was fixed on implementation of Service Bulletin PDP 0068-01 Main Digital pcb. No other faulty components were found. The mounting solder on the main processor socket was cracked on one corner at the pcb mount point. (See last picture in PDP 0068-01, page 2) Re-soldered same, and the set has worked faultlessly since. I became convinced over time that the fault was to do with the main processor board, as the failures were so random, and the set would otherwise run perfectly. This fault is caused by a combination of solder fatigue, vibration and the thermal cycling of the pcb over time. I expect it is a cause of many of the reported problems experienced on these Fujitsu panels. I suggest that the above work should only be attempted by suitably skilled person/s, as very fine soldering and knowledge of electronic pcb repair techniques are required.