Friday, Jul 11, 2014 at 10:55
olcoolone,
You were lucky with your fly back experience, I have seen EHT jump across a high voltage probe a throw a tech across a room when a XRAY protection circuit failed to kick in on a large CRT set, amazingly the tech involved only suffered a few bruises from his fall, mind you he refused to work on that particular model if it came in to the
shop again.
I see where your coming from, however the article was in technical magazine for techo's and not a sales blurb, it was written by a tech that works for a company supplying various makes of equipment to the RV and off-
grid power market, he working in their repair center acting as both a local service agent and doing warranty work for manufactures and suppliers of this type of equipment, and also liaising back with the manufactures as to common and unusual service issue that should arise with respect to their equipment. This is common practice in any large volume repair center.
Repairing second hand radios for friends is not the same as running a electronics repair company where you have 20 or 30 units a day crossing your
test bench, and relying on it as your source of income,
you pretty quickly get to see which items have high failure rates.
I have run my own business for over 40 years, including doing authorised warranty work for many companies operating in different fields. The problems experienced by the author above are common place, I have seen TV horizontal output transistors fitted with heat sinks that are half the size of the main board and weigh so much that they have cracked the board!
The use of 105C is common place in most products to save a few cents, ask any electronics tech, first thing you do with power supply faults, is an ESR
test on the electrolytics and swap out the dried out ones with high temp types.
Simply fact is like any other device electronics are built to a price, I remember one highly respected manufacture back in the last days of VCR's that put out a model we had a lot of problems with, by that time all VCR's had moved away from separate power supplies to switched mode types on the main board. This particular model had semi reverted in that it had a separate power supply in a can that was mounted via plugs directly to the main PCB. I found that the power supplies in this model would become unstable (just out of warranty usually) and either overheat or go over voltage and destroy the VCR. Tried everything I could think of to correct the problem but nothing worked. Had several discussions with the companies tech support and they couldn't supply a fix either apart from a cost prohibitive new power supply (interesting too that it had been designed a a plug in unit) this continued till there was a couple of house fires attributed to the VCR in question. The companies solution was to issue a service bulletin to their authorised service centers to replace the power supply free of charge if the VCR was presented faulty. They did not perform a general recall.
Another company had a TV that would regularly blow up the vertical output chip, over the life of the model they put out around 6 service bulletins describing various changes to correct the problem, they didn't, IC's still kept failing, they then put out a revised IC's still didn't cure the issue. Was glad when they finally replaced the model with a new one until we discovered it still had basically the same vertical output stage in the new model and the same failure rate. I don't know how much the company made out of selling the vertical output IC concerned but gudging by just how many we went through at around $40 a pop it must have been considerable! This also triggered a market in third supply of the chip concerned, yet the company still sold "lots" of the set concerned.
As for manufactures designing high failure rates, I don't believe any engineer would purposely design a unit to have a high failure rate just happens sometimes and then is not cost effective for the comapny concerned to re-engineer it, it happens. Generally the public aren't aware, the service industry loves them as they become bread and butter jobs, one look and you know the problem, and time is money, these are the jobs you make a profit on, it's the reliable equipment that's a pain in the bum, you rarely see them, they usually present as different faults when they do come in and generally take hours to diagnose, and then you never see that fault again which means you loose money on them:(
By the way their has been a couple of companies that have had to change their names due to the high failure rate of their equipment and bad image in the industry.
Problem with consumer electronics these days is its not cost effective to repair most things unless your doing warranty work that is, this is why many business that haven't diversified into other areas of electronics are shutting up
shop.
Some like myself started taking on automotive electronics work many years ago from auto elects etc to keep the cash coming in, the problem now is most manufactures have gone to black box design ie they get the electronics modules designed by other companies, these companies don't supply service info, they use propriety components etc, some units you can reverse engineer and repair providing the components are available, once supply of the modules and or components run out then that will be that. You'll probably be able to get after market engine management systems to keep your vintage car going but you certainly going to have problems sourcing a body ECU for example.
At least in the consumer electronics area (brown goods) service information is generally available, auto electronics is a whole different kettle of fish, generally service info is not available, companies like VDO in the early days went to considerable lengths to try and prevent third party repairs, they too as described above would grind off part numbers and won't supply schematics etc. This has carried over in to other areas of auto electronics ie battery chargers, if you try and obtain detailed specs or service information, again as described above then the companies will come back with it is propriety information and commercially sensitive, it a battery charger for gods sake!
If someone really wanted to steel their secrets they would just get a Chinese company to reverse engineer a unit, the Chinese are much better at reverse engineering than they are at designing equipment themselves, the American chip manufactures these days get the Chinese to reverse engineer their chips when they have a production line issue they can't resolve to locate what the problem is! They have got it down so pat that they can copy the chip so accurately that the firmware is copied across too!
What these companies are really saying is we don't want third party repair business to cheap repairs to their equipment, instead you have to return it to our service center and we will quote the repair at a price that you'll just buy a new one.
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