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Hitachi 50EX10B - RED Horiz Convergence out, then ALL out
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NoDFs



Joined: 31 May 2009
Posts: 6
Location: Missouri

PostPosted: Sun May 31, 2009 3:27 pm    Post subject: Hitachi 50EX10B - RED Horiz Convergence out, then ALL out Reply with quote

A friend recently donated the TV to me because he thought I might be able to fix it. The problem materialized in his possession... RED became bowed in from the left side of the screen throwing off the convergence of RED. He tried adjusting the convergence board but could not so he offered it to me.

Originally, no RED Horizontal convergence board adjustments were responding when I turned them. This is a complete row on the convergence board. When using the MENU I could move RED and BLUE cross-hair around using a remote. I then made things worse by unplugging then replugging each of the 2 connectors from the convergence board one at a time seeing the effects in an attempt to maybe reset something. The convergences changed then went back upon replugging them back in. I figured there was not much voltage and risk of permanent damage to anything.

I was wrong. Now none of the controls on the convergence board does anything, nor are the crosshairs of any color moveable using the convergence adjust in the MENU.

My question is...

Can the problem be only the convergence board, the Power(HV)/Deflection board, or is the problem shared by both boards?

I don't want to spend any money I don't have to and I am hoping it is an obvious problem for someone with experience to at least be able to narrow it down.

I am aware of convergence repair kits and am hoping that is all I need. Also, I haven't checked the fuses, like the mini covergence fuse either.

Thanks if you can help.

Aaron
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jts1957



Joined: 24 Nov 2008
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PostPosted: Sun May 31, 2009 7:29 pm    Post subject: Reply with quote

When the CUSTOMER convergence controls were NOT working, why would you then expect the SERVICE ones to respond? Question
Once you discovered the customer controls dead - that's the point you should have thrown parts at it. Idea
NOW instead of, most likely, replacing the IC's and checking for resistors that changed in value or opened and then touching up the customer convergence controls - you're, at least, going to have to do full service convergence. Surprised
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PostPosted: Sun May 31, 2009 8:12 pm    Post subject: Reply with quote

jts1957 wrote:
When the CUSTOMER convergence controls were NOT working, why would you then expect the SERVICE ones to respond? Question
Once you discovered the customer controls dead - that's the point you should have thrown parts at it. Idea
NOW instead of, most likely, replacing the IC's and checking for resistors that changed in value or opened and then touching up the customer convergence controls - you're, at least, going to have to do full service convergence. Surprised


It's my 3rd day researching this problem. I didn't think that I would find as much hope in fixing the TV as I did, only after I mades things worse.

jts1957, I was hoping you would respond, can you please be more constructive? What now?

Every one of the CUSTOMER (I am guessing convergence board) controls were messed with before I got the TV. A full service convergence was already inevitable.

The SERVICE (I am guessing MENU driven convergence) controls were working when I got the TV (ie. RED).

I would like to know if it still looks like a problem involving the STK4274's & relative resistors, just more resistors now?
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jts1957



Joined: 24 Nov 2008
Posts: 2476
Location: Far, Far Away

PostPosted: Sun May 31, 2009 9:43 pm    Post subject: Reply with quote

The Customer controls are the ones the user has access to without any set disassembly - The service controls either require partial disassemble to access OR a special service menu needs to be accessed.

Any way you look at it, you're going to have to check resistors and swap IC's, so may as well start there. Also check fuses / make sure convergence IC's get power.

It amazes me how may people think that if "the set was working fine one day, and all of a sudden the convergence (or vertical sweep) is WAY OFF," that the set MUST just need an "adjustment!?"
That "may" be true if the set got that way over weeks, if not months, but usually the REAL solution is still the same: Find the part(s) that failed - replace them - and NO Adjustment should be necessary! Rolling Eyes
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minnie



Joined: 18 Aug 2005
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PostPosted: Sun May 31, 2009 9:47 pm    Post subject: Reply with quote

What jts1957 means is now you have to replace the convergence ic's and check the bias resistors.
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jts1957



Joined: 24 Nov 2008
Posts: 2476
Location: Far, Far Away

PostPosted: Sun May 31, 2009 9:57 pm    Post subject: Reply with quote

jts1957 wrote:
... you're going to have to check resistors and swap IC's, so may as well start there. ...


I thought I just said that. Confused
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NoDFs



Joined: 31 May 2009
Posts: 6
Location: Missouri

PostPosted: Mon Jun 01, 2009 12:01 am    Post subject: Reply with quote

jts1957 wrote:
jts1957 wrote:
... you're going to have to check resistors and swap IC's, so may as well start there. ...


I thought I just said that. :?


I did get that out of the first half of your post jts1957.

I, like many here, am not a technician necessarily. I am just good enough to fix this problem if it is just the ICs & resistors. So, without gettting an experienced answer into this exact problem or TV I am just gonna go with what I have read into the answers & other posts elsewhere and keep my fingers crossed that the fix will only be around $100. Not a bad price to pay for a free TV eh?

Using the service manual (PDF) I will start with all of the fuses. Then check the voltages on the Convergence board. Then get STK4274's from bdent.com and resistors known to be bad from whoever.

Thanks and good luck to ME!!
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minnie



Joined: 18 Aug 2005
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PostPosted: Mon Jun 01, 2009 4:22 am    Post subject: Reply with quote

jts1957 can be a little short, I don't ever recall having to replace any resistors when replacing the STK4274's . These are transistors not STK's. Replace them and post back.
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NoDFs



Joined: 31 May 2009
Posts: 6
Location: Missouri

PostPosted: Sat Jul 04, 2009 5:50 pm    Post subject: Got grid or remote? Reply with quote

Ok, I finally got to it... I replaced the STKs and upon doing so noticed that there were 2 burnt resistors and an open micro fuse (cocnvergence). Replaced them and WHAMMO. The convergence is now working but obviously needs adjusting. I bought a replacement remote from Anderic but it is not fully compatible though it is sold as such. The "100" button doesn't change the convergence crosshair to grid mode.

I might have to record a grid pattern DVD and play it on the TV for adjustment.

Anybody have any ideas? or know of a replacement remote with the "100" button doing its job?

Thanks
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minnie



Joined: 18 Aug 2005
Posts: 2880
Location: Hell

PostPosted: Sat Jul 04, 2009 9:33 pm    Post subject: Reply with quote

I sent you the service manual. First thing first have you gone into the customer menu and adjusted the convergence? This set uses pots for adjustment it looks like.
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