Riddled TV Repair Forum
Service Menu and Manual Schematics
 
   
 FAQFAQ   SearchSearch   RegisterRegister 
   Log inLog in 
Hitachi 57F59A - Power LED - Relay Click - No picture   Goto page 1, 2  Next  
Post new topic   Reply to topic    Riddled TV Repair Forum Index -> TV Repair
 
Author Message
Frankie



Joined: 26 Feb 2011
Posts: 11
Location: Tampa, FL

PostPosted: Sat Feb 26, 2011 11:28 pm    Post subject: Hitachi 57F59A - Power LED - Relay Click - No picture Reply with quote

Hitachi 57" CRT RPTV
Model 57F59A
Chassis DP65G

Hey guys and girls, I'm sure you hear it constantly, but first time poster here with a broken TV that needs some help. I'm familiar with working on electronics as I'm a tube amplifier hobbyist, but I really don't even know where to start trying to diagnose this TV. I also don't want to start poking around until I understand the capacitor discharge method for this thing. I've been whacked by a tube amp before, that's no fun!

Okay, so onto the problem, I have a Hitachi 57F59A CRT RPTV here that won't display anything. The set powers on, I can hear the relay click, I can hear the audio amplifier working (it just hisses, I don't hear any actual signal), the LED on the front illuminates, but I can't get anything on the screen. None of the buttons on the remote or on the front of the TV bring up the menu or channels or anything.

I pulled the back panel and checked the 3 fuses on the board on the right hand side; they all tested for continuity on my meter. What I did notice is that there's a diagnostic panel inside the TV showing the location of an LED on that board. No matter what the LED isn't lit, I don't know if that's relevant.

So yeah, that's where I'm at now. I got the set open, I got my meter, I got my toolbox, I even got my soldering iron nearby... I just don't know where to start. Help! And thanks in advance.

Also, here are some pictures I took of inside the set. They're high res, but still crappy cell phone pics, so I'm just posting links to them in case you're on a slow connection.

http://www.cowboymafia.net/frankie/tv/1.jpg
http://www.cowboymafia.net/frankie/tv/2.jpg
http://www.cowboymafia.net/frankie/tv/3.jpg
http://www.cowboymafia.net/frankie/tv/4.jpg

Also, I got me a service manual and I've stepped down through the diagnostic.



I've got 5V at D949, I can hear the relay click, I have 115V at D945, so I visually inspected the components in order. Everything looks okay, but Q777 (on the right) looks a little misshapen/cracked. Here's a picture:



Is that part supposed to look like that or did it blow out? None of the other components on the heat shield have the bulge in the back like that. Or is Q777 that big brown deal and I'm looking at the wrong part? That bulge might not even be a bulge, it could be a reflection. It's pretty hard to see in that thing! Heeeelp! Very Happy


Last edited by Frankie on Sat Feb 26, 2011 11:46 pm; edited 1 time in total
Google

PostPost subject: Advertisement

Frankie



Joined: 26 Feb 2011
Posts: 11
Location: Tampa, FL

PostPosted: Sat Feb 26, 2011 11:34 pm    Post subject: Reply with quote

I should also add that prior to it just taking its football and going home, sometimes the TV would lose one color. I'd have to turn it off, wait 10-30 seconds, and turn it back on and it'd be fine. This normally happened when the kids were on a video game bender, so the TV would be on for a while before this happened. Bad IC? Blown capacitor? I eyeballed and re-eyeballed all the caps on the board, I don't see anything visually cooked and I don't want to haphazardly start probing things, I might cause even more damage. Again, thanks in advance for any help!
Frankie



Joined: 26 Feb 2011
Posts: 11
Location: Tampa, FL

PostPosted: Sat Feb 26, 2011 11:50 pm    Post subject: Reply with quote

One more thing to add, the heat sink nearest the AC plug gets warm, but all of the other ones are ice cold when the set is powered on in its current state. Not sure if that matters, but hey, the sticky said to be as detailed as possible so I'm trying to be. Very Happy
murfy888



Joined: 02 Mar 2011
Posts: 6
Location: philippines

PostPosted: Fri Mar 04, 2011 1:16 am    Post subject: Reply with quote

Check CRT socket. Does heater filament light up? Can you read any G2 voltage? Check or replace CRT socket... I think this is the problem..
Frankie



Joined: 26 Feb 2011
Posts: 11
Location: Tampa, FL

PostPosted: Sun Mar 06, 2011 6:37 pm    Post subject: Reply with quote

Murfy, I think you called it! This set has 3 CRT's, and I should be seeing red filaments in them much like a vacuum tube in a guitar amplifier, right? None of them are lit, not even a faint glow in the dark, so I assume you may have found the problem. Do you know what to check off hand? I'm going to dive into the schematic right now and see if I can make heads or tails out of the heater runs.
Google

PostPost subject: Advertisement

Frankie



Joined: 26 Feb 2011
Posts: 11
Location: Tampa, FL

PostPosted: Tue Mar 08, 2011 6:54 pm    Post subject: Reply with quote



T902 appears to feed the heaters for the CRT's, and it's not really giving me any of the expected voltages. I'm seeing -300vdc or so at those E test points, not +24, +28, etc... Should I assume T902 needs to be replaced? I also tested I908 as per the service manual it directly feeds the heaters, and it's giving me large negative voltages too of ~90vdc, not the expected +6-+24vdc as indicated in the manual.
JTS1957



Joined: 21 Jan 2009
Posts: 2305
Location: Far, Far Away

PostPosted: Wed Mar 09, 2011 2:52 am    Post subject: Reply with quote

REFERENCING what? Hot ground, Cold ground?
doyed



Joined: 05 Apr 2011
Posts: 1
Location: Mexico

PostPosted: Tue Apr 05, 2011 2:29 pm    Post subject: same trouble Reply with quote

I'm in the same trouble with the same tv model.I can see the heaters on,the fly back is working,audio ampliefer is workink two,but no any raster on screen. I traced R,G,B signal out from jugla IC(TA1360AFG)and singnal is OK, vertical IC and pincushion IC's (STK's)normal voltage.the led diagnosis doesen't work to me
¿anyone has another idea?
Tony M



Joined: 01 May 2011
Posts: 1
Location: seattle wa

PostPosted: Sun May 01, 2011 12:02 pm    Post subject: Same issue Reply with quote

Frankie, if you get this please reply with your findings on the rptv no picture issue. I am curious and share the same concern on my TV.
Rockstar



Joined: 26 Oct 2008
Posts: 43

PostPosted: Thu May 26, 2011 12:47 am    Post subject: Reply with quote

Check the vertical Ic for crack solder joints I had 2 Hitachi hd rear projection tvs that had the no picture or sound and flyback transformer didnt have the static sound of starting up.
Display posts from previous:   
Post new topic   Reply to topic    Riddled TV Repair Forum Index -> TV Repair All times are GMT - 6 Hours
Goto page 1, 2  Next
Page 1 of 2

 


Disclaimer: All information provided by RiddledTV is strictly for information purposes only. Please observe all warnings displayed on your electronic
devices. This information should only be used to help diagnose work, and all service should be performed by a qualified technician.
Contact Us       Privacy Policy       Copyright © 2015 RiddledTV.com       Advertise on RiddedTV.com