Help with Sony 34XBR800 7 blinks Whats most likely cause

I have a friend who loves this set and it's been not working for a while. He asked me to look at it and I'll get it next week so I thought I''d do some research . The diagnostics light blinks 7 times indicating the problem is in the horizontal deflection circuit. The Schematics I have are very hard to read and I assume Q8001 and Q8013 are the output transistors and the most likely cause They are IRF 1B7N 50 A which I can't find a source for is there a sub or do I need go to sony Is there something else I should be looking at ?

Thanks in advance Bob

Reply to
Boboranntrottier
Loading thread data ...

Assuming the two white Micron fusible resistors are OK, your problem is IC8002, a MCZ3001D. Replace it with the DB suffix version. We do lots of these.

Mark Z.

Reply to
Mark Zacharias

MArk Thanks I ordered one and hopefully that solves it Also what are the reference designators for the resistors you mention I couldn't locate them on teh schematic Bob

Reply to
Boboranntrottier

Don't know the reference numbers for the resistors offhand, they are pretty obvious along the outer edge of the board, halfway between the flyback and the board edge which is nearer the front of the set. They are very low value, .1 ohm if memory serves, and sit near a couple fairly large capacitors. If one of these resistors is bad the flyback probably went bad and hammered the switcher transistors and horizontal output. This is much less common, however.

Would have been a good idea to check those resistors BEFORE ordering the part, though...

Mark Z.

Reply to
Mark Zacharias

Thansk again I had him confirm that it blinked 7 times so today when he drops it off outside my house its zero degrees and it sits there for 3-4 hours I get it inside and opened up and it runs fine I get five blinks on the diags which I assume is just the white balance Any thoughts?? I'll probabaly change the chip anyway Thanks again

Reply to
Boboranntrottier

These things are often intermittent. I'd change the chip anyway. 5 blinks may be a video driver IC on the CRT board, but that would usually not be intermittent. Maybe just a screen adjustment on the FBT.

Mark Z.

Reply to
Mark Zacharias

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.