Horizontal Sync Problems with Sony and Mitsubishi sets

Check and replace all the electrolytic capacitors at the power secondary side [DC] side. If you wish to get some details; check the site linked here. Viewing it in "Mosaic" or "Magazine" will make surf easy. Pull up older posts. Surf the site with patience. Do a search by type in the brand name of your device at its search box and press "Enter".
http://electronicshelponline.blogspot.com/

This is a older model and likely the first generation of HD set made by Mitsubishi---where the HD input is on rear (DTV?) ARE THERE TWO JACKS MARKED H sync and V sync?

If they are there set needed an external box made only by Mitsubishi for for later HD use.

This problems is the tv Projection Light Engine design flaw with it IC chip.These problems happen to many models of it DLP tvs Big Screen 60 and up.Mitsubishi,Samsung,Sony,Toshiba all used the same IC chip on their 60 and up on their DLP tvs Big Screen.Tries make deal with Mitsubishi help u split the cost of repair the tv Projection Light Engine by replacing the IC chip or replaced the entire Projection Light Engine system.This problems is not new,been going on for a few years.Many people when on Youtube **** about this problems with white dots showing up on their tvs screens and multiplying rapidly.

I left the set completely turned off (unplugged) all day. When I turned the set on in the evening,
both channels had sound. So other than resetting the circuits the problem seems to have been eliminated for now. If it recurs, I'll contact you folks. This is sort of flaky, just last month I had a similar problem with Channel 26 digital in Chicago but that seems to have been resolved. Since I have 2 other Sony TVs in my house and they are NOT experiencing the same problems.
I'm not so sure my next set will be a Sony. Although I do not tune into WYCC digital in Chicago
all that much, I like to know that my set is working properly and that I'm able to look at any channel
20.1 & 20.2 included, without loosing the audio.

If I understand you correctly:
The horizontal output transistor in your TV blew.

You replaced it with a BU2520DF.

I'm not sure what you mean by "change to dynamic mode".

Dynamic what?

Usually, horizontal problems in TVs are caused by bad capacitors in either the sync circuit, the driver circuit, the geometry circuit or the output circuit.

When I repsir problems like this I use an oscilliscope to find which stage is not working properly, then start substituting the capacitors in that stage until the problem is solved.

Look for large orange or blue ceramic or polyprop capacitors with bulges or cracks in them.

Look for electrolytic capacitors with bulging tops or shrunk cases.

Check and make sure no resistors are brown, they may be blown.

Use an ohm meter to test low value resistors in circuit.

If you don't have an oscilliscopw, that's about all you can do.

horizontal lines = horizontal sync off . mitsbishi always seemed to have this problem .. on the older sets I would take the back off and inside deep on the board i would adjust a pot and sync it right .... and never had a recall, maybe your newer model has this too .. this little control,

but its a horizontal sync problem.

if no change the horizontal processing ic.

The sync is automatic and controled by the uPC. It is strongly not recomended to mess with the factory service set-up. There are no so-called user adjustable controls for the horizontal and vertical frequency on this model.

The fault is usualy failed components in the sync seperator and sync amp sections.

An experienced TV tech can troubleshoot this and replace the necessary parts for you.


Jerry G.

check data cabel pin13 H-sync

That is not a vertical roll from side to side, this is a horizontal rolling. if the vertical had a roll it would be going from top to bottom. This is most likely a coupling between the horizontal sync circuit and the sync separator circuit. Good Luck