Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Flat Panels & Digital Format

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #1  
Old 07-03-2016, 06:59 PM
Boobtubeman's Avatar
Boobtubeman Boobtubeman is offline
<---WANTED: Motorola 17P6
 
Join Date: Jun 2007
Location: Woodland Ca.
Posts: 761
Flatscreen virgins grand opening

Decided to pop my cherry on a flatpannel tv given to me from work after it quit.

It was used to play safety DVDs once or twice a month, so I presume it has low mileage... Nothing invested in it at this point, but i figured ide give it a go- or give it a toss....

Basicly, i plug it in, push the power button, red LED lights an i hear a pop from the speakers as you normally would and.....THATS IT.... If i push the power button again, the LED will blink, ill hear a pop, and nothing else, It wont even load a DVD.. Same behavior if i use the remote on it....

Ive opened it and shot some pics... E-caps arent bulged and... thats as far as i know about these sets!! heheh

Please feel free to chime in if you have experience with this model and can get me started in the right direction

Thanks...
SR
Attached Images
File Type: jpg 20160703_135214.jpg (41.9 KB, 78 views)
File Type: jpg 20160703_134944.jpg (63.6 KB, 93 views)
File Type: jpg 20160703_135040.jpg (52.7 KB, 77 views)
Reply With Quote
  #2  
Old 07-03-2016, 07:44 PM
N2IXK's Avatar
N2IXK N2IXK is offline
Technohippie
 
Join Date: Apr 2011
Location: Sittin' on the "Group W" bench...
Posts: 739
Have you found any service info on ElectroTanya or the other manual/schematic sites?

I would start by looking for the power cabling between the power supply/backlight board and the Signal board and DVD player board. Often the proper voltage rails are marked on the connector. Typically you would have a 5VSB (standby-on all the time), +15, +5, and +3.3V, and perhaps a few others. See that they come up when power is applied. If not, look for shorted components on the affected rail, or an open/high ESR filter cap or a blown fuse.
Reply With Quote
  #3  
Old 07-03-2016, 11:32 PM
Boobtubeman's Avatar
Boobtubeman Boobtubeman is offline
<---WANTED: Motorola 17P6
 
Join Date: Jun 2007
Location: Woodland Ca.
Posts: 761
Any links to the manual i need? electrotanya wasnt completely in english, had trouble navigating it.. Not seeing any volt listings on the boards..

SR
Reply With Quote
  #4  
Old 07-04-2016, 06:29 AM
dr.ido's Avatar
dr.ido dr.ido is offline
VideoKarma Member
 
Join Date: Mar 2005
Location: SE Melbourne, Australia
Posts: 514
You may find a schematic for the power supply board by looking up the part number. Looks like a MEGMET power supply used in a lot of off brand sets, so it will be something like MLT666. Seen them in sets sold under many different names here. I've seen an almost identical sets, but the ProScan brand isn't used here.

From the sets behaviour it sounds like the power supply is shutting down when the TV comes out of standby. The first thing I'd be looking for is shorted diodes, though that isn't the only possible fault. On these they're on the top right corner of the board near the connectors. The voltages should me marked near the connectors, possibly on the bottom side of the board.
Reply With Quote
  #5  
Old 07-04-2016, 11:49 AM
dieseljeep dieseljeep is offline
VideoKarma Member
 
Join Date: Jul 2010
Posts: 5,748
Quote:
Originally Posted by dr.ido View Post
You may find a schematic for the power supply board by looking up the part number. Looks like a MEGMET power supply used in a lot of off brand sets, so it will be something like MLT666. Seen them in sets sold under many different names here. I've seen an almost identical sets, but the ProScan brand isn't used here.

From the sets behaviour it sounds like the power supply is shutting down when the TV comes out of standby. The first thing I'd be looking for is shorted diodes, though that isn't the only possible fault. On these they're on the top right corner of the board near the connectors. The voltages should me marked near the connectors, possibly on the bottom side of the board.
ProScan was supposed to be the premium RCA product.
I got a headache just looking at the pictures.
The thing consumes 130 watts. I thought those things were supposed to be energy efficient.
Reply With Quote
Audiokarma
  #6  
Old 07-04-2016, 09:19 PM
walterbeers walterbeers is offline
Old TVs are better!
 
Join Date: Jun 2011
Location: Omaha NE
Posts: 447
I'm far from an expert on flatscreens, but it appears that the power supply and video (Y sustain?) is combined into one board, the big one of the left of the middle photo. Check for shorted transistors and diodes. Find the part number on the board and you might be able to find a good used replacement on e - bay. I don't know if it's a plasma or LCD, but looking at the power consumption, that lead me to think it might be a plasma screen. Just googled the model number, It's not a plasma it's a LCD set.

Last edited by walterbeers; 07-04-2016 at 09:22 PM.
Reply With Quote
  #7  
Old 07-04-2016, 09:27 PM
Boobtubeman's Avatar
Boobtubeman Boobtubeman is offline
<---WANTED: Motorola 17P6
 
Join Date: Jun 2007
Location: Woodland Ca.
Posts: 761
Poked around online and found this pic of my supply (hope its okay to use)

Didnt see the voltage markings till now..

The pic my gal shot of this board was so blurry,(pain pill) i had to look around for a match and i do believe this is the one.... Definitely a match side by side..


SR
Attached Images
File Type: jpg power-supply-.jpg (80.6 KB, 42 views)
File Type: jpg 20160703_135005.jpg (66.8 KB, 37 views)
Reply With Quote
  #8  
Old 07-04-2016, 10:26 PM
centralradio centralradio is offline
VideoKarma Member
 
Join Date: Feb 2014
Posts: 963
You can make a request on http://www.freeservicemanuals.net .The guys might have a manual there for free for you.You got to join for free to do so..
Reply With Quote
  #9  
Old 07-04-2016, 11:54 PM
mstaton's Avatar
mstaton mstaton is offline
"Book em Dano!"
 
Join Date: May 2011
Location: Caldwell, Id
Posts: 1,592
Power supply with the inverter for the ccfl lamps. Y sustains are in plasmas only. shine a bright light on the screen while pushing the menu button and see if there's anything there. check for shorted mosfets or fet's. check continuity on the inverter transformers or a blown micro fuse
__________________
"It's a mad mad mad mad world" !!
http://www.youtube.com/user/mwstaton64?feature=mhee
Reply With Quote
  #10  
Old 07-05-2016, 07:08 PM
Boobtubeman's Avatar
Boobtubeman Boobtubeman is offline
<---WANTED: Motorola 17P6
 
Join Date: Jun 2007
Location: Woodland Ca.
Posts: 761
Quote:
Originally Posted by dieseljeep View Post
ProScan was supposed to be the premium RCA product.
I got a headache just looking at the pictures.
The thing consumes 130 watts. I thought those things were supposed to be energy efficient.
Even sadder? This tv spent its life (7 yrs) being carried from an office--- plugged in---- Ran for 15 minutes showing a DVD --Unplugged---Returned to the office---ONCE A MONTH... Talk about LOW HOURS..

I wonder if the plug in/out--in/out didnt surge the Power supply? And if i do find a defective part on this board can those teeny-tiny parts be replaced?? I see some micro tools in my future..

SR
Reply With Quote
Audiokarma
  #11  
Old 07-06-2016, 03:41 AM
Boobtubeman's Avatar
Boobtubeman Boobtubeman is offline
<---WANTED: Motorola 17P6
 
Join Date: Jun 2007
Location: Woodland Ca.
Posts: 761
Took some voltage readings: 5v standby is present, hooked up to the 12v tap and tried a power up, voltage jumps up then drops, so its safe to assume the power supply is trying to come up but shuts back down. So dr.ido's guess is looking valid..

Ebay sells repair kits for this board, most seem to focus on the 2 caps near the connectors.. Are the mfd ratings that critical for these boards? I may have some good ones from some salvaged receivers exept the voltage ratings may be higher I dont have the ESR meter to check the current ones, may need to do some cap swapping since a no bulge cap can still be bad... Any ideas?

Your input is most appreciated..

SR
Reply With Quote
  #12  
Old 07-06-2016, 07:09 AM
dr.ido's Avatar
dr.ido dr.ido is offline
VideoKarma Member
 
Join Date: Mar 2005
Location: SE Melbourne, Australia
Posts: 514
The caps are not that critical in these (there are some exceptions, but not for this board). As long as the voltage rating is at least as high as the original and the capacitance is somewhere near (eg, replacing a 2200uf with 3300uf or vice-versa) it will work. Near the 2 caps near the connectors the zener diode and the to-220 package diode often short in these.

That said, if the 12V rail is coming up at all the short isn't on the 12V rail.

In your set there is a small DC-DC sub-board mounted between the power supply and the tcon board. These can and do fail shorted. If it has failed it could shut down the power supply board, disconnect it and see if anything changes.
Reply With Quote
  #13  
Old 07-06-2016, 03:38 PM
Boobtubeman's Avatar
Boobtubeman Boobtubeman is offline
<---WANTED: Motorola 17P6
 
Join Date: Jun 2007
Location: Woodland Ca.
Posts: 761
If you are referring to the small board with the round copper transformer, i unplugged it and it changed nothing except the speakers werent popping anymore. can the diodes be tested in circuit? if yes, i may have a shorted glass diode near the to-220 near the connectors.. (it read near zero both ways)..

SR
Reply With Quote
  #14  
Old 07-06-2016, 03:44 PM
N2IXK's Avatar
N2IXK N2IXK is offline
Technohippie
 
Join Date: Apr 2011
Location: Sittin' on the "Group W" bench...
Posts: 739
Diodes can USUALLY be tested in circuit, but not always. One that reads zero in both directions is definitely suspicious. Lift one end and recheck before replacing it though.
Reply With Quote
  #15  
Old 07-06-2016, 05:08 PM
Zenith26kc20's Avatar
Zenith26kc20 Zenith26kc20 is offline
VideoKarma Member
 
Join Date: Apr 2009
Location: New Orleans
Posts: 801
Biggest problem I have had with these is the backlight boards. Look for discoloration under the transformers on the backlight board. This is a sign the transformers were overheating/failing and that shorts the driver transistors. I would check all the driver transistors for shorts on the backlight board. If one is bad, I have never been lucky to replace the transformer and transistor. I would replace the board if any shorts are evident.
Reply With Quote
Audiokarma
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 10:28 AM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
ęCopyright 2012 VideoKarma.org, All rights reserved.