RCA L42WD22 No Picture

[retiredcaps]

Re: RCA L42WD22 No Picture

They had a number of problems due to poor control techniques, so a former Chief Petty Officer (Bob) was placed in charge. It took him 6 months to get the place squared away.

Not to mention shopjimmy.com's inventory has pictures of boards with bad caps on it (presumably for sale?). See (enlarge it and look at top right hand corner)

http://www.shopjimmy.com/westinghous...rter-board.htm

Must remember to ask CEOs of small fast growing companies if they have a Bob equivalent before I invest $$$ into the company.

[Fodder4Thought]

Re: RCA L42WD22 No Picture

Attached are some photos that I hope are more helpful. If not, let me know and I'll try again with a different camera.

[Fodder4Thought]

Re: RCA L42WD22 No Picture

It may be. Or it may not be.

In a nutshell, here is the problem. Two Gorges Electronics in China designs a 42" LCD TV. They produce a few prototypes and offer them to several importers. 'Worst Buy' says they will buy 1000 with an Unsignia label. Two Gorges orders the parts to build 2000 and continues to pitch the product. Technicolor SA comes along and orders 2000 with an RCA label. Two Gorges orders the parts to build another 2000. One of their suppliers says 'So sorry, that inverter not available, we have new part. Works better, just have to remove diode on main board.' To speed delivery of Technicolor's order, Two Gorges starts to build the TVs using the old inverter. When the new inverter comes in, they switch to the new ones, and make sure the main boards are correct. POSSIBLY the label indicates a different revision level, but don't count on it.

The result in is you have 2000 TVs, but some of the parts from the early production are not compatible with those from late production. And NOBODY pays attention to revision levels, even though supposedly identical boards show little resemblance to one another.

That doesn't even begin to consider the problems possible in ShopJimmy's operation. One horrendous example of what can go wrong occurred at the company I worked for about 30 years ago. (This might be boring, quit now.)

The circuit board stockroom had about 50,000 circuit boards on hand. They had a number of problems due to poor control techniques, so a former Chief Petty Officer (Bob) was placed in charge. It took him 6 months to get the place squared away. Obsolete boards were either updated or scrapped. An accurate count of all product was made. They started using a triple entry system to keep track of inventory and location. Two were on hard copy, the part numbers and quantity information was kept on a computer. Any stock pulled or added was initialed by the person doing the work. As a result, anyone could look up a board number, go to the corridor, bay, and shelf indicated and expect to find that number of boards there. In addition, anyone could go to a particular shelf and find a card which indicated the number of boards on the shelf, and who had placed them there, and who had removed boards.

Bob made it known that he would be checking shelves, and there would be fireworks if the numbers on the computer, the history log, the shelf card, and the the boards on the shelf did not match. After the workers figured out Bob was serious, and especially when they learned the new system was easier (no hunting for boards which SHOULD be in a certain bay) things ran very smoothly and calmly.

Things went to heck when management decided Bob's talents were required elsewhere, and the stockroom was placed under the control of accounting. Accountants know how to count, and manage inventory, right? The first thing they changed was to get rid of the triple entry system. 'We'll do it right the first time'. The number of boards was kept on the computer. The location of the boards was kept in the history file. When a new batch of boards was received, they were stored on the first available shelf, and the location entered in the history file. As a result, one shelf could have multiple kinds of boards, and when pulling boards it might be necessary to go to several shelves to find enough. The folly of that approach was becoming obvious when I left the company, but I heard that it got REALLY bad within 2 months. Quantities in the computer did not match the history log, locations were wrong, you name it, it went wrong.

PlainBill

Ah. That sheds some light on things. I hope I don't have to replace the Master board, too, but that's a more desirable outcome than having to give up on the TV entirely.

[PlainBill]

Re: RCA L42WD22 No Picture

Ah. That sheds some light on things. I hope I don't have to replace the Master board, too, but that's a more desirable outcome than having to give up on the TV entirely.

Here is some information that ties in with my earlier post.

The board you received from Shopjimmy was a 6632L-0372A. According to Electronica USA that is for a L42WD22 (among others).

The original board was a 6632L-0449A. Again, according to Electronica USA that is for a L42WD22YX6 (among others). Note the difference in model numbers.

According to an eBay auction, the boards must be used in matched pairs. And another eBay auction has the repair kit for $18.

I would NOT recommend buying a new master to go with your slave; get the correct slave, or repair the one you have.

PlainBill

[Fodder4Thought]

Re: RCA L42WD22 No Picture

Here is some information that ties in with my earlier post.

The board you received from Shopjimmy was a 6632L-0372A. According to Electronica USA that is for a L42WD22 (among others).

The original board was a 6632L-0449A. Again, according to Electronica USA that is for a L42WD22YX6 (among others). Note the difference in model numbers.

According to an eBay auction, the boards must be used in matched pairs. And another eBay auction has the repair kit for $18.

I would NOT recommend buying a new master to go with your slave; get the correct slave, or repair the one you have.

PlainBill

Repair kit, you say? What's in it?

I'm on a budget, so I'm hoping I can return the new board and fix this.

[PlainBill]

Re: RCA L42WD22 No Picture

Repair kit, you say? What's in it?

One IC and 4 transistors according to the blurb.

I'm on a budget, so I'm hoping I can return the new board and fix this.

Dang!!! And I was hoping you would offer to fly me to Hawaii!!!

PlainBill

[Fodder4Thought]

Re: RCA L42WD22 No Picture

One IC and 4 transistors according to the blurb.



Dang!!! And I was hoping you would offer to fly me to Hawaii!!!

PlainBill

Do you by chance have a link to this repair kit, or the search terms you used?

As for Hawaii - I'm right there with you, buddy.

[PlainBill]

Re: RCA L42WD22 No Picture

Do you by chance have a link to this repair kit, or the search terms you used?

6632L-0449A

As for Hawaii - I'm right there with you, buddy.

I don't want you to TAKE me to Hawaii, I want you to SEND me to Hawaii.

PlainBill

[Fodder4Thought]

Re: RCA L42WD22 No Picture

Update:

I spoke with ShopJimmy, and they told me that (surprise, surprise) I'd mistakenly ordered by model number, rather than part number. So, I ordered the right part (and will return the other soon), and installed it when it came in the mail.

It lives!

While I kind of wish I'd gotten the repair kit and fixed the old board, I'm more than satisfied that the replacement board fixed the TV.

Thanks for all your help!

[PlainBill]

Re: RCA L42WD22 No Picture

Update:

I spoke with ShopJimmy, and they told me that (surprise, surprise) I'd mistakenly ordered by model number, rather than part number. So, I ordered the right part (and will return the other soon), and installed it when it came in the mail.

It lives!

While I kind of wish I'd gotten the repair kit and fixed the old board, I'm more than satisfied that the replacement board fixed the TV.

Thanks for all your help!

This is one of the problems facing anyone trying to repair a flat screen TV. Most manufacturers buy the LCD panel as a unit with the tcon, inverter and CCFLs already installed. As far as they are concerned, the inverter is not a replaceable part. And there are good reasons for doing it this way. The chief one is the TV manufacturer can purchase the LCD panels strictly by size and resolution. The world of manufacturing hates to be tied to a single source; a minor glitch in a vendors production facility can shut down an entire assembly line.

However, we are smart - we know the inverter (and tcon) are replaceable parts. Except that their may be several different ones used in a particular model.

PlainBill

[mconnelly]

Re: RCA L42WD22 No Picture

so did everyone just replace the whole slave board? i'm having the same issue

[PlainBill]

Re: RCA L42WD22 No Picture

so did everyone just replace the whole slave board? i'm having the same issue

It depends on your skill level and the equipment you have available. The slave IS repairable, but the mosfets have to be replaced. These are large package (TO-252) SMT devices, so a temperature controlled hot air workstation is the preferred way to remove the old parts.

A parts kit is $16, the workstation to install the parts will run $100 minimum.

PlainBill

[mconnelly]

Re: RCA L42WD22 No Picture

damn. so its the small pieces. Is there a wayto test them without removing from the board?
Where can i find the kit (/whats in it) ?
I live in SW Ontario

Thx for your time.

[mconnelly]

Re: RCA L42WD22 No Picture

scratch the whats in it portion found that, just need to find it now lol

[PlainBill]

Re: RCA L42WD22 No Picture

damn. so its the small pieces. Is there a wayto test them without removing from the board?
Where can i find the kit (/whats in it) ?
I live in SW Ontario

Thx for your time.

The kit is available on eBay. Search for 6632L-0449A.

The transistors can be tested on the board - just measure the resistance G-D, G-S, D-S with the meter set on the 200 ohms scale. Each reading should show open. (Look up the FDD8447L datasheet for pin identification).

PlainBill

[mconnelly]

Re: RCA L42WD22 No Picture

should the numbers on the parts line up, the ebay item i found differs from what is currently on the board

[PlainBill]

Re: RCA L42WD22 No Picture

should the numbers on the parts line up, the ebay item i found differs from what is currently on the board

What parts are currently on the board? The may be supplying upgraded parts.

PlainBill

[mconnelly]

Re: RCA L42WD22 No Picture

Sorry for not getting back I had to leave on a business trip.
I decided that I've been too busy as of late to just buy the replacement board from shopjimmy. It seemed to work however I have a feeling I may have put something together wrong or not tight enough. (yes the model # on the new board matched with the older busted one)

Do these symptoms sound like my mistake in reassembling or possibly a part.

After using the TV turning it off works fine, turning it back on the green power light comes on and nothing happens - attempting to turn it off with the remote just flashes the green light as if its receiving the signal but nothing else happens, light stays on.

Upon unplugging and plugging it in the green light comes on (i think its supposed to temporarily) then does not go out.

I unplugged it over night and plugged it in in the morning, the green light came on temporarily then went out, then turning the TV on works.

The other variable I'm not sure of is the power cord. I have several computers power cords laying around and I honestly couldn't tell which was from the tv after returning from my trip, could using the wrong one be the/an issue?

Thx,
Mark

[cadiman]

Re: RCA L42WD22 No Picture

Those look like inverters from an AU-optronics panel.

My 42 had a bad mosfet on slave inverter and bad ccfls (3).

[cadiman]

Re: RCA L42WD22 No Picture

Sometning went wrong with my last post.

Those are inverters from an au-optronics panel.

Mine had a bad mosfet on the slave inverter and 3 bad ccfls.