Sanyo Plasma Model: DP42740 Has glow but nothing else.

[Tedybear]

Hello all.

Been having pretty good luck with LCD's and such, so I did manage to nip up a cheap plasma for repair. (I know, glutton for punishment)

It's a Sanyo DP42740 Chassis: P42740-05

Please let me know what, if any picture would be needed and I'll follow suit. However all the capacitors seem to be in extremely good condition. The set itself has a build date of 2012.

Woman I picked it up from described the initial issue: No picture, has sound. She then put it into a storage bin until she found my advert. The storage bin appears to have had a water leak, as there is very minor water 'crust' on the lower right of the inner frame. While it looks like it should be an issue? I do not feel that is the cause of the problems. (Trying to avoid the expected knee jerk reactions)

Here's what the set does:

Plug the set in--you hear 3 relay clicks. Two 'rapid' and one more at a slight delay. The two clicks are the power supply main relays. The 3rd click seems to be the upper relay clicking an additional time-likely shutting 'off'. There is a green LED on the buffer board--It reminds me of a fluorescent bulb starting up. A touch 'dim' for a second kinda flickers. Then snaps on at a normal brightness. Upon examine of the screen itself we have a very noticeable "Glow" with the entire screen. So that tells me that the plasma boards themselves are getting juice and the screen is waiting for a picture input. (That's also how I know that dry crust at the lower right side isn't having an effect on the screen--it's not blown/blowing any fuses and the voltages seem to be okay as far as I can tell)

It almost seems like the set is turning the plasma screen 'on' and then not turning on anything else. As we have no action otherwise. I can press the buttons on the control panel and it's also dead.


I did notice a repair kit that shows for chassis ending in 04. This one appears to have the same double-connected tuner/main board. The repair kit is made to solve the issue of it cycle clicking on/off and audio issues. We sorta have a clicking thing going on, but it's not clicking on/off every few seconds as the service info seems to state that cures.


Wondering if anyone has run into this problem before. I can of course supply photos as requested. In order to get a better set of numbers for voltages, does anyone have a pinout of the PSB? It looks like I have the correct voltages, but it's got a PITA "Darfon" with limited information for a power board.

S-

[tw2005]

Re: Sanyo Plasma Model: DP42740 Has glow but nothing else.

Since the sustains are on and panel glowing I'd hazard a guess at either the main board or the D board. If i had to pick one I'd probably go main since the control panel is dead.

[Tedybear]

Re: Sanyo Plasma Model: DP42740 Has glow but nothing else.

Since the sustains are on and panel glowing I'd hazard a guess at either the main board or the D board. If i had to pick one I'd probably go main since the control panel is dead.

I get the feeling you're on the mark.

I've been itching to brush up on my SMD work, and this set didn't cost more then a few bucks. I'll likely grab the repair 'kit' and give it a wack. Worse case I'll have to invest in a replacement board for a few bucks. LOL. Or I might just be that "Good". (What's that saying? Pride comith before the fall?)

Sense I haven't a clue really on plasma sets. Which one would be considered to be the "D" board. (like I said. I've had good luck with PS board repairs and cap ID and swap outs on LCD sets. Plasma I get kinda lost...)

S-

[tw2005]

Re: Sanyo Plasma Model: DP42740 Has glow but nothing else.

If you go to shopjimmy and search your model you'll see all the various boards plus revisions depending on model version.

you'll spot the D board.
Small board that interfaces the main to the rest of the TV, often samsung and LG have logic control boards. newer Pannys only have A boards, but this Sanyo is a panasonic display in a Sanyo case with a Sanyo main board

[Tedybear]

Re: Sanyo Plasma Model: DP42740 Has glow but nothing else.

If you go to shopjimmy and search your model you'll see all the various boards plus revisions depending on model version.

you'll spot the D board.
Small board that interfaces the main to the rest of the TV, often samsung and LG have logic control boards. newer Pannys only have A boards, but this Sanyo is a panasonic display in a Sanyo case with a Sanyo main board

Have to love it when companies merge and combine resources. Like the Philip set with Samsung parts in it. Nothing like Badge Swapping. Reminds me of a local firm that does two brands of light bulbs (westinghouse and GE.) Major company did a bulk order of bulbs from the supplier and was dead set against one of the name brands. So they returned several thousand of bulbs back to the factory--The factory buffed off the brand ID mark on the bulb and reprinted the other company ID mark where the old one was. Both brands where built by the same company to the same standards--just the logo was different. Brand loyality gone amuck.

I think I'll see if I can locate that repair kit--Should be fun to try--and it it fails the other board is still available at a somewhat reasonable cost.


S-

[Tedybear]

Re: Sanyo Plasma Model: DP42740 Has glow but nothing else.

Quick question. I removed the main board from the set. Just for the heck of it I plugged it in with this board not installed.

The set still fired up and did the exact same thing with the relays clicking and the glow from the plasma screen.

If the main board was removed from the system--and the only other board left 'controlling' the power supply (for a lack of a better word) Shouldn't the set remain totally dead? I'm starting to wonder if this board is good, and the issue might reside with the 'd' board?

Or is this actually how it works--and I'm just overthinking things.

S-

[Tedybear]

Re: Sanyo Plasma Model: DP42740 Has glow but nothing else.

Quick question. I removed the main board from the set. Just for the heck of it I plugged it in with this board not installed.

The set still fired up and did the exact same thing with the relays clicking and the glow from the plasma screen.

If the main board was removed from the system--and the only other board left 'controlling' the power supply (for a lack of a better word) Shouldn't the set remain totally dead? I'm starting to wonder if this board is good, and the issue might reside with the 'd' board?

Or is this actually how it works--and I'm just overthinking things.

S-

D board is all over eBay as "New Other" or "Used working pull" and it's under 15 bucks in almost all cases.

I'll hold off until I get a response about the question:

If I remove completely the "Main Board" with the cables to the speakers and the ribbon type cable to the "D" logic board. So that board is removed....

I plug the set in and get the same response. Two clicks and then 1 relay click. The plasma still fires up the power board in regards to the backglow of the screen. If that board is fully removed--Should---or shouldn't the TV attempt to do this??

Or would I be better off ordering in the repair 'kit' and the "D" board and just have it over with?

Just trying to understand things. If that main board tells, via the "D" board to kick things 'on'-- Because things seem to be kicking 'on' to some extent. If that main board is removed from the circuit-- Should the set still react the same way? Or should it now become dead and not responsive at all.

Does that make any sense? It seems like the D board is still flagging the set to turn 'on' even though the main board is removed.

S-

[tw2005]

Re: Sanyo Plasma Model: DP42740 Has glow but nothing else.

D board is all over eBay as "New Other" or "Used working pull" and it's under 15 bucks in almost all cases.

I'll hold off until I get a response about the question:

If I remove completely the "Main Board" with the cables to the speakers and the ribbon type cable to the "D" logic board. So that board is removed....

I plug the set in and get the same response. Two clicks and then 1 relay click. The plasma still fires up the power board in regards to the backglow of the screen. If that board is fully removed--Should---or shouldn't the TV attempt to do this??

Or would I be better off ordering in the repair 'kit' and the "D" board and just have it over with?

Just trying to understand things. If that main board tells, via the "D" board to kick things 'on'-- Because things seem to be kicking 'on' to some extent. If that main board is removed from the circuit-- Should the set still react the same way? Or should it now become dead and not responsive at all.

Does that make any sense? It seems like the D board is still flagging the set to turn 'on' even though the main board is removed.

S-

that may point to mainboard then. In some other panasonic models isolating the mainboard from the D board will turn the TV on with no image, usually full white with no LVDS cable connected. The 2010 3D VT20/25 series comes to mind. the internals of that Sanyo is really 2010 gen panny panel, equivalent would be a 42C2,X2 etc.
best i can do for a hybrid TV, I don't get to see anything like that here, just the 100% panasonic models

[Tedybear]

Re: Sanyo Plasma Model: DP42740 Has glow but nothing else.

that may point to mainboard then. In some other panasonic models isolating the mainboard from the D board will turn the TV on with no image, usually full white with no LVDS cable connected. The 2010 3D VT20/25 series comes to mind. the internals of that Sanyo is really 2010 gen panny panel, equivalent would be a 42C2,X2 etc.
best i can do for a hybrid TV, I don't get to see anything like that here, just the 100% panasonic models

The "D" board oddly enough is Panasonic on the chips. Kinda looks like this one happened to be built when Sanyo was taken over by Panasonic. As it has a mix-match between the both.

I do not remember if we had a "white screen" or not. I'll nip up one of the repair kits and move forward that way.

Thanks for the reply!!

S-

[tw2005]

Re: Sanyo Plasma Model: DP42740 Has glow but nothing else.

The "D" board oddly enough is Panasonic on the chips. Kinda looks like this one happened to be built when Sanyo was taken over by Panasonic. As it has a mix-match between the both.

I do not remember if we had a "white screen" or not. I'll nip up one of the repair kits and move forward that way.

Thanks for the reply!!

S-

D board is a panny term , so yes. The panel would be supplied complete with all boards to drive the panel with the D board added to suit the main, then often it'll be a customer supplied main and power board buit in shopjimmy i think there's a number of power boards including the one panasonic would use.

[Tedybear]

Re: Sanyo Plasma Model: DP42740 Has glow but nothing else.

D board is a panny term , so yes. The panel would be supplied complete with all boards to drive the panel with the D board added to suit the main, then often it'll be a customer supplied main and power board buit in shopjimmy i think there's a number of power boards including the one panasonic would use.

That makes sense. One company does the plasma displays and ships them to the end user/company that then adds their own hardware/software/etc...to 'personalize' it as being what ever brand/features they want to sell.

I'll pick up that repair 'kit' and give it a wack. Just an eprom and the audio chip. Should be interesting. Shame it doesn't quite fit what this set did when it first took a dump. (First sign of problems was just no picture and good sound?. Then sits in a storage bin for a while and I get it and all I have is clicks and plasma glow.) I can let it sit there for 15 minutes....just smiles with a green light plasma glow..and nothing else.

S-