Mitsubishi VS-60805 Pincushioned Convergence (edit)

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Zuben
Mitsubishi VS-60805 Pincushioned Convergence (edit)

I have a Mitsubishi VS-60805 (4:3 HDTV, Chassis V16).  TV was on for several hours (before Hurricane Ike hit our area), but display shut off while green power light stayed steady on.  Remote will power on/off TV.

I can hear caps charge up when plugged in and hear clicking when power is turned on.  Projection tubes glow, but no display is seen (not even blue "video mute" screen).  Have tried alternate video input with no success.

I was able to remove the chassis (thanks to service manuals from Larry for a similar model).  I  tested continuity for ALL pico fuses and they are fine.  Two pico fuses on the main power supply board are soldered to resistors in series and occupy one fuse slot.  One fuse/resistor pair shows darkening on the ends, but continuity is there.

However, a small cap (16V 47microfarad, C410 on the power board) appears to have leaked all fluid.  Don't have schematics, but wonder if this may be the problem.  All other caps looks fine (i.e., no swollen tops or leakage).  I got a replacement at Radio Shack and will swap out tonight.

Would still like feedback on this if you could provide some. 

Zuben
Follow up:  Removed old cap

Follow up:  Removed old cap (C410 on power board), cleaned up mineral oil and replaced with new cap. 

Powers up and now displays video signal (yeah!), but horrible convergence (pincushioned).

I'm guessing that both convergence ICs will need to be replaced, based on others with similar issues.

Larry Dillon:  If you're reading, I really could use some assistance in finding the replacement ICs and some instructions on replacing them in this unit.  Please send to glennlray at peoplepc  .   com

Alnp
Good work finding the bad cap

Good work finding the bad cap.

You can determine which chassis you have and which ic('s) you need from this post:
http://www.techlore.com/forum/thread/18547/Mitsubishi-convergence-IC-s-u...

And see some recommended substitutes here:
http://www.techlore.com/forum/thread/22659/STK392-XXX-Spec-s/?highlight=...

Zuben
Okay...took me long enough,

Okay...took me long enough, but I finally got around to replacing both convergence ICs (STK392-040).  Unfortunately, I still have very bad pincushioned convergence.

I noted the following in Larry Dillon's article, http://www.techlore.com/article/22530/DIY-Repair-Replacing-Convergence-IC-s-on-a-Mitsubshi-TV-Set

"If the set comes on, but the convergence is way out, you may have a bad feedback resistor or two. If you messed with the convergence before you replaced the IC, you may need a pro to assist you in making the final convergence adjustments."

Can anyone (Larry, are you out there? Cool) help me locate the feedback resistor(s) for this unit so I can try replacing them as well?

I'm nearly at the hair-pulling stage, and frankly don't have much left to work with! Laughing

Zuben
Bumping again...trying to get

Bumping again...trying to get on Larry's radar!

Zuben
Update: Well, the issue was

Update: Well, the issue was NOT a blown capacitor, but rather a glycol leak from one of the projection tubes which caused a short in the circuitry. Additionally, the E2PROM was reset, so now I need your help.

Does anyone here have a Mitsubishi VS-60805 or VS-50805 television that is in good working order? I would like to get your deflection jungle values from the service menu so I can get my set back and running. Analog convergence is good, but digital is keystoned (sideways a bit) and I really need to start with reasonable values.

Or - does anyone know if I can get these values from Mitsubishi? This goes beyond what is shown in the service manual; it only shows a range of values that each parameter might be set to, but not a specific, ideal value.

Thanks in advance for your help. This would take some time and I'd be glad to compensate anyone for their time. Reply to this thread first, and then we can exchange contact info.

 

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