LCD TV Repair Training Manual/Book Source

Given the overall decline in the service industry, and the way modules are returned for factory repair -- or products are simply thrown away -- it's unlikely there are any such books.

Google 'LCD TV repair manual' You will get numerous hits, including commercial sites, e-books, and hard copy books. A common failure point on these sets is the power supply.

PlainBill

To be honest, there's not an awful lot to repair on them. By far and away, the two commonest problems are the power supplies, and backlight inverters. The power supplies are just generally just multi-stage switchers (standby supply, PFC supply and main supply - that's effectively three mostly independant switchers on one board). Most failures are fairly obvious. Chips with the tops blown off, bulging or open circuit caps, bad lead-free joints etc. Most boards have 'repair kits' available for them, where you just replace everything that comes in the kit, and turn back on. 99% of cases, that is then an end to the problem. Most TV switchers are pretty well behaved, once they have been properly repaired. Also, there are not all that many different types. An awful lot of LCD TVs are just badged from a few different manufacturers, and you will quickly see similar if not identical modules popping up in sets that are completely different on the outside.

Worst case, if you really can't fix a particular power supply, the whole module is often available at an unrealistically cheap price from either the manufacturer, or their spares agent. If the name on the front is something obscure, you may well recognise the supply as being the same as one fitted to a major brand set. You can then just buy one of those instead.

The biggest problem is schematics. Even if you can get a schematic set for the whole TV, you will often find that the PSU is shown just as a 'block'. Spares can also be a problem, with 'obscure' surface mount devices often being used. This ceases to be a problem if you use a repair kit, but in some cases, these are 'shotgun', and may contain devices to fix several different common problems, and thus cost a fair bit more than you would pay trade for just the devices that are *actually* faulty. That said, unless you are very experienced with switchers, I would always recommend replacing ALL of the items that come in the kit, as sometimes, some little diode or whatever, that appears to have nothing at all to do with the components that you

*have* found faulty, is actually the original cause of the cascade failure that you thought that you had gotten to the bottom of ... :-(

Backlight inverter boards suffer from bad joints, bad transistors, bad transformers, and bad caps for the most part. Again parts can be a problem, and it is often better to source a replacement board, then keep the old one to cull parts from for the future.

Other than that, there's not too much else that you're going to be able to repair. For sure, you can get audio IC problems, and cap failures and so on in other areas of the sets, but in general, main board failures are going to be beyond the diagnostic abilities of a 'normally' equipped and trained engineer.

Hope that is of some practical help to you.

Arfa

Did the world suddenly change overnight?

In this particular case William, yes. I can only assume that the manufacturers heavily subsidise the cost of replacement PSU boards in order to preserve their (good) name in the market place. They don't seem to have caught on to the fact that engineers will often order one of these cheap boards to fix a set that is from a completely different manufacturer, but happens to use the same power supply, or even complete chassis. No chassis number or serial number or old power supply return, is required. From some sources, you don't even need to be trade.

If you look for instance at the Vestel 17PWxx series of power supplies, used in a lot of different manufacturers' sets, and many of which are actually interchangable if you know what you are doing, or have adaptor harnesses (although almost identical circuitry-wise and physically, later versions have slightly different connector pinning), you will find that the proper price is anywhere around the £100 ($160) mark. However, they are for sale, brand new from many sources, including manufacturers' direct spares agents, for as little as £32 ($50). I do a repair service on them for a little less than that.

These are a very complex and well built supply, and at least £80 is what you would truthfully *expect* to pay for one.

Arfa