I'm confused about this post: This is an older sony projo, is it not? If memory serves, you may also want to check the convergence system. I suspect that you have a flakey conv amp and/or solder problem there. Believe it or not, bad conv will blank these sets! Most of the time the condition is perminent due to an amp shorting and blowing a pico fuse or two. Jim McVey McVey Alltronix 327 Broadway Newburgh Ny 12550 ph: 845 561 8383 fx: 845 561 9017 Consumer electronics & computer service. Factory authorized for over twenty brands. ----- Original Message ----- From: "James M. Osburn" <josbu@xxxxxxxxxxxxxxxx> To: "Techassist" <techassist@xxxxxxxxxxxxx> Sent: Tuesday, April 13, 2004 6:52 PM Subject: [TechAssist] Sony projection KP46XBR25 1k blanking > Hi Techs, > I am working on this set that has a wierd problem. Set comes on normally, > has a good pix then after about 15 minutes the pix blanks out. I suspected a > bad tube and checked all 3 with my Sencore CR-70. None showed to have shorts > or weak emission. > Next I replaced the jungle chip IC302 with original Sony part. Problem still > exists. Tried to isolate with freeze spray with no success.The CRT heaters > and HV are all ok. I have not done a lot of 1k blanking troubleshooting on > these sets so after researching it a bit I discovered that you can tell if > the jungle IC is putting out the 3 1k pulses by looking for a bright line at > the top of the screen for all 3 tubes when the set is acting up. My red and > blue lines are there but my green is missing when the set is blanked. Also > another wierd thing is when the set is blanked and I try to turn up the > green screen control the red and blue tubes get dimmer. The red and blue > screen controls act normal. I have the service manual on CD rom (old > version) and have the new Sony ESI for this year, unfortunately they > neglected to tell me that they were changing to DVD format which my computer > doesn't support. It's always something. Can anyone help shed any light on > this wierd problem? Any input is greatly appreciated. > Mark Osburn > J.M. Audio Video Repair > 3701 Carthage Street > Fort Smith, Arkansas > 72903 > josbu@xxxxxxxxxxxxxxxx > > > > -------------------------------------------------------------------------- --- > Lost Password: > http://www.tech-assist.org and select "Login Problems?". > Email Archives: > //www.freelists.org/archives/techassist/ > ----------------------------------------------------------------------------- Lost Password: http://www.tech-assist.org and select "Login Problems?". Email Archives: //www.freelists.org/archives/techassist/