Riddled TV Repair Forum

whaven · Joined: 12 May 2008 Posts: 4 Location: SLC

Hi..

here's my problem....I have a 51" HDTV rear projection that was recemtly moved. When I turned it on I got a picture that was hourglassed shaped ( slightly bended at the top and bottom and bowed in at the sides).
The picture is otherwise ok, some slight convergence, but the colors aren't that badly seperated.

At first I tried to used the manual multi-point convergence adjustment. That made a nicer picture but did not solved the problem. I tried adjusting the focus on the flyby and lens...no luck.

I removed the convergence board and re-soldered the convergence ICs and check the resistors..again no luck

Finally I replaced the two convergence IC STK 392-120....the problem still exist....but the picture is fairly good....

Can anyone help me on this one?

Google

kuhurdler · Joined: 28 Dec 2006 Posts: 2582 Location: Overland Park, KS

check the resistors and the caps around the convergence ICs.

whaven · Joined: 12 May 2008 Posts: 4 Location: SLC

I check the resistors and caps around the ICs no luck...does anyone know where I might find the service manual for this model?

kuhurdler · Joined: 28 Dec 2006 Posts: 2582 Location: Overland Park, KS

I think you'll have to purchase a service manual. if you want one. Philips no longer provides them to servicers for free.

Since I don't know your level of experience yet, Can you tell me how you checked the caps?

whaven · Joined: 12 May 2008 Posts: 4 Location: SLC

Sure and thanks for the help....I don't have a cap checker on my multimeter so I placed my meter in ohm mode and check the leads on the caps and watch the impedence rise to open and then reversed the meter leads and watch it rise again.

Google

Pionex · Joined: 19 Apr 2008 Posts: 1 Location: Workshop

I am repairing the identical set, the customer complained that the picture size was shrinking, by the time I got to the set it was not coming on at all when I opened the set I saw about 5 or 6 components that look like carbon resistors burnt beyond recognition in area of the FBT and the location numbers are unreadable because of the burn, some of the numbers are 3902, 3907 and 3909 can any one help me identify these components and possible replacement as I do not have a schematic.
Thanks in advance

whaven · Joined: 12 May 2008 Posts: 4 Location: SLC

I will attempt to ID these components for you

Jesse Mack · Joined: 22 May 2008 Posts: 600 Location: The Last Frontier

This problem can be caused by a power interrupt and back when philips was philips they were fully aware of the problem. They simply said the fix was to simply realign the set. What has happened is you have corrupt/lost data in the DCU (digital convergence unit).
Here is the rub. I do this for a living and I can tell you it is not advisable for you to try to correct this yourself. It WILL require a template. If you do not have one it can be made of clear mylar sheet if you have a service manual that gives the spacing.
The reason I do not advise that you do this yourself is that it is highly probable that your results will be much much worse if it is done wrong. The first one I did took me four hours and I know what and how to do it. I can now do it in about two hours. You have to realign all three colors, not just the red and blue and a template is mandatory. This is an alignment procedure that many current, servicing technicians to not relish.
If you insist on doing this yourself BE FOREWARNED. it is not easy.

Jesse