electronics, repairs, service manuals and datasheets discussion community for the repairs professionals and technicians
FAQSearchMembersGroupsRegisterProfilePM'sLogin/Out
Hitachi Television Dead
Goto page Previous  1, 2, 3, 4
 
Post new topic   Reply to topic    Electronic equipment repair and service manual search discussion Forum Index -> Equipment Repairs
View previous topic :: View next topic  
Author Message
jts1957



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

PostPosted: Wed Jan 19, 2011 4:59 am    Post subject: Reply with quote

C605

How does the picture (crosshatch pattern) look? Any linearity or size (esp. vertically) problems?
_________________
You're over there, I'm over here.
Back to top
View user's profile Send private message
beertap



Joined: 04 Jan 2011
Posts: 22

PostPosted: Fri Jan 28, 2011 1:55 am    Post subject: Reply with quote

I have replaced C605 and I601 with no luck. Also, I soldered the convergence chips back in and removed the connection (pin 12) between the power supply board and signal board on PPS3 connector. Next, I turned on the TV and it came up but convergence is a little off and I am unable to get to the menu to set it. None of the channel numbers or volume bar at bottom of screen are displayed although I am able to change channels and control the volume.

At one point, I plugged everything back together and turned on the TV and of course the clicking started. Next with TV off, I unplugged one of the deflection yokes and turned on the unit. Only sound could be heard and while the sound was on I plugged the deflection yoke back in and the picture came on with sound. I still had the convergence issue as before so I tried to go to the menu to adjust it but as soon as I pressed menu on the remote the TV cut off and started clicking. Before the TV went off and screen went dark, I was able to see the menu shown on the screen. I can repeat this process.
Back to top
View user's profile Send private message
beertap



Joined: 04 Jan 2011
Posts: 22

PostPosted: Sat Jan 29, 2011 4:24 am    Post subject: Reply with quote

I have a TDA8174A as vertical amplifier. My conclusion is that this IC is being put in to shutdown/protection due to some underlying problem. I have replaced it and continue to have the same issues with TV. Any ideas on what to check next?
Back to top
View user's profile Send private message
jts1957



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

PostPosted: Sat Jan 29, 2011 5:25 am    Post subject: Reply with quote

Does vertical blanking signal make it from the vertical output IC to convergence and microprocessor?
_________________
You're over there, I'm over here.
Back to top
View user's profile Send private message
beertap



Joined: 04 Jan 2011
Posts: 22

PostPosted: Sun Jan 30, 2011 3:38 am    Post subject: Reply with quote

The vertical blanking signal does make it to convergence (tested at RK64) and microprocessor (tested at R310 and at PIN64 on processor). The signal patterns match perfectly with what is shown in schematics compared with what is shown on my scope. The voltages were approximate.
Back to top
View user's profile Send private message
beertap



Joined: 04 Jan 2011
Posts: 22

PostPosted: Tue Feb 01, 2011 1:32 am    Post subject: Reply with quote

What to do next? hmm...maybe shoot it! haha. No kidding a side, I think it is a weird problem. I can take away the signal going to the processor and the TV will come on but put it back and the TV is dead.
Back to top
View user's profile Send private message
jts1957



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

PostPosted: Tue Feb 01, 2011 2:49 am    Post subject: Reply with quote

Shoot it now or shoot it when you get home? "Rabbit Seasoning."

I demand that you to shoot it now!
_________________
You're over there, I'm over here.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Electronic equipment repair and service manual search discussion Forum Index -> Equipment Repairs All times are GMT
Goto page Previous  1, 2, 3, 4
Page 4 of 4

 
Jump to:  
You can post new topics in this forum
You can reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


eServiceInfo on FB - Service Manuals Free Download - Service Diagrams

Free TV Schematics Download - HARDW.net - Pinout Master - Jabse Search - Jabse.InK  - Pulsator

SnimkiOt.com - Poblizo.com : пътешествия