Sharp LC-42DH77E

[OldLes]

Yesterday, a visit to the local amenity site yielded this very tidy looking set. It even had a helpful note suggesting "faulty inverter board, ideal for spares".
At switch on, brief green LED, 9 orange LED flashes (booting up period?) and a green LED. Screen "Wakes up", and an OSD message suggests CVCS-1 input (I think), followed by shutdown.
When I looked inside, I saw evidence of some overheating at the two connection points of the inverter board to the top two of 18 lamps.
I have yet to see if I can find any component faults, but if none, can I simply leave the top two lamps disconnected for testing purposes.
I am inclined to remove the two plastic clip connection holders, and wire these two lamps directly.
I don't see any superficial evidence of damage to the ends of the lamps compared with the ones lower down.
Any comments on this procedure? (If successful, I will be keeping this set for me).
OldLes.

[marky mark]

Do you mean the white clips that go into the screen? If so, just replace them.

[OldLes]

Mark, the little white clips had overheated, but a repair attempt had been made previously, with an extra thin sliver of copper soldered onto the inverter board's contact point. However, in its original overheat, the temper was obviously lost by the clip, and it was obviously unsuccessful.
I checked all the fuses, compared resistance readings of all the bigger semicons, but found nothing amiss.
So I dismembered the two plastic clips, bent the back part and crimped a short length of wire to each one. I then removed all the overheated connector area of the pcb, and soldered the wires directly.
Connected back up, but still the same.
There was one page from a service note in the back of the set, which says that if there is a fault on the inverter, after five start up attempts, it will be blocked. Maybe this has happened.
I will search for a service manual (or does anybody here have one?) and see what to try next.
I don't have a remote, so not sure if I should buy one. I don't want to throw good money after no money, but it may be necessary.
Les.

[downunder]

Most likely a faulty lamp. To check,remove the front plastic cabinet section, remove the LCD panel and diffusion sheets under it, to expose the lamp cavity. Best disconnect the Flexis from the T-Con to the panel. Dont need them for this test and you dont want to tear them. At this stage the set is operational but has no LCD panel.Lay the set on it's back, switch it on and wait for the lamps to switch on briefly. After repeat switch-ons you should be able to identify any lamps that do not ignite or light with a pinkish glow. Even 1 lamp below par will trigger the protection on these. Nor can you run them with 2 lamps disconnected.

[Kilroys]

You had to do a lamp error reset,
The best way is to change all the 18
lampsocket, becourse sooner or later some of the others
will do a bad connection with the inverterboard.

[clark97]

I have plenty of lamps and some connectors for this set if needed, they do suffer from lamp failure probably due to the white clips failing resulting in intermitent connections, I have the manual and all the service updates for modified connectors I'll put it in the downloads section.

[clark97]

It won't let me upload it, if you need it I can email it to you.

[OldLes]

Clark97, I now have the manual (earlier messager loaded it) but any updates will be useful. I will PM you with my email address.
I am satisfied that my "bodge" has given me 18 good connections, so I need to see next if any of my tubes are faulty. If so, I would be happy to receive some.
I have some tubes from a 26" which came my way last week, a "Vistron" with cracked screen, so probaly all good. Can I temporarily hang some of these externally to test things out?
Do you have the remote I could buy or borrow?
OldLes.

[OldLes]

Clark97, I have only just opened the document which Kilroys uploaded, and realised it is only pages 1-5 of chapter 3.
So, "yes please, may I have the complete manual".
I have just sent you a PM with my email address.
OldLes.

[OldLes]

Well, after about 2 hours in Terminal (Ubuntu 10.04) I finally managed to "Un-Rar" the manual. I then went further and reorganised it into one complete pdf. Now I just need to study it a while before I get back to the set itself. If I can fix it, it will take pride of place in the living room, and the existing one will be up on the bedroom wall to keep SWMBO happy.
Thanks Clark97.

OldLes.

[OldLes]

Right, some progress. I have a Sharp remote which will switch it on and off, so it may do everything when I get it running properly.
So, darkened room, and switch on. After normal boot up, the screen illumination showed that three of the CCFLs were not firing up.
So, that is my next step.
Clark97, I will be sending you a PM.
Les.

[OldLes]

At the time of the last message, I had established that three of the CCFLs did not seem to be lighting up during the 2 to 3 second (test?) period before the set shut down.
I came across a Samsung 41" set with cracked screen, but its backlighting was OK, so I managed to rescue some tubes. I dismantled the screen assembly, and removed the three previously concluded as faulty tubes. The Samsung tubes were a little shorter, but I soldered on a short extension and made some (sort of tie wrap) connections. Reassembled everything and tried again. This time, it appeared that there were FOUR faulty tubes, none of which were the replacement ones!!!!
I have today tested the originally condemned three tubes, and they all work OK on the new tester.
What next? Hmm, maybe ------
Les

[downunder]

Your final statement may not be so strange, Les. I've removed non-operating ccfls from Sharps, then at a later date, installed them in another Sharp to discover that they work. Go figure. I prefer to operate them with the ccfl cavity exposed (no panel) so I can see exactly what's going on. Good luck with it.

[Turnip]

Hi folks,
Had one in today with a couple of those edge connectors burned out.

Noticed ChasHyde do them for 3.80 plus but (as there are 18) thought to try hard wire the duff ones first.

Problem was - that on re-fitting the inverter panel, several of the other connectors didn't make contact.

Had that sinking feeling so think to hard wire the lot - Only problem is - those springy clips won't solder, neither will the tube wire ends.

Think to wrap wire under the clips, and do a 18 tube hard wire job.

Recall edge connectors with single sided print always crap - Speccy - Pye tellies of the 70's - Chris.

[OldLes]

Turnip, my set is still awaiting further attempts to fix. In fact today we decided that that was on the list for next Monday afternoon, when my pal arrives and we play at "digital stuff" with a low success rate!
We thought we had this fixed, after hard wiring the two burned out ones, but whilst it would attempt a start up, we found DIFFERENT lamps were now not lighting. I don't think we tested them with the new tester, and this is our next move. Good luck, and if you win, PLEASE report back!!
Les.