Almost the same thing happened to me.
I had been on the lookout for a second music synthesizer of the type I had (for back up as well as use in a second location). After scouring the usual internet sites for used synths, I came up empty at a price range I was willing to pay. So I just cast a broad net (no pun intended) to see if anyone out on the web had it. Sure enough, someone was offering to sell it at effectively $100 plus shipping, way below "used retail". The catch was that there was an audio problem they had not been able to resolve. Long story short...I bought it as I do have some experience in audio electronics and figured I could fix it.
Got the unit...opened it up, and NO bulging capacitors, no burn marks...etc....nothing obvious to indicate a problem in the audio circuitry except that it didn't work. There was a lot of SMD components so I didn't want to fool around with them until I had a better clue as to the issue.
Once more to the net to look for similar complaints and solutions. Again, long story short...other owners had found repeated problems with 2 under-rated SMD resistors in the output amplifiers stages which failed 'open'. I replaced those and we were off to the races again. Good as new. While under the hood, I also replaced the headphone jack which had been damaged by leaving the plug in place while moving the synth, effectively leveraging the plug so as to crack the jack completely.
Total cost to me for a synth worth about $2K was about $150, with $3+tax being for parts.
And also a cheer to Mike for keeping yet another 20 or so lbs of e-Waste from landfill, in defiance to what the TV place was recommending.
I think there's a particular stripe that runs through the boomer generation of engineers that I don't see anymore. We see something electronic broken and our minds immediately race with quick diagnosis and potential repair approach. This calling orginates from back before the birth of the PC, in budding young (future) electronic designers eagerly building Archer kits and projects featured in electronics hobby magazines of the time. I recall literally dozens of electronic hobby component shops around the city through the 70's. Nowadays, I count perhaps 2 or 3, serving a population that is about 4 times what it was back then. I visit one regularly when I'm visiting relatives (I live in a different city now), and can't help but notice that most of the other patrons are middle-aged men such as myself. 3 decades ago, this place would have been overrun by guys in their teens and early 20's (counting myself among them), eagerly searching the rows of shelves with parts lists in hand.
I'm sure Mike has similar memories and a background that allowed him to confidently crack open an "unrepairable" device, and succeed. Power to ya Mike! We are a fast disappearing breed!
Actually the confidence to crack open something, for me, came from my father.
An immigrant with not a lot of money and not even a high school education would fix cars, toasters, TV's (remember the tube testers?), basically anything that broke. This was out of necessity.
I do this now for friends. When they ask me how I have the confidence to open it up, I sum up my fathers philosophy as "Why not open it up? It's already broken and you might see something simple like a wire. Even if you don't fix it, you might learn something."
I'm with you there Rick! One of my favorite rants-um, I mean "topics" is the disappearence of the "real" engineers. I too started by building my own stuff when I was a "kid"; p-p wiring, etching my own boards (layed out with tape and donuts). Kits, "repurposed" stuff. My first "computer" was hand wired and programmed by flipping switches. When I started my "professional career" I was lucky enough to catch the tail end of working with guys that were REAL Engineers (they were always 10-15 years within retirement). These were the guys that regardless of their "discipline" would tackle anything; EE's that built hot-rods, ME's that were into shortwave radio and had 60 foot antenna's in their backyards. They were "thinkers and do'ers". You could ask them something and if they didn't know they could at least point you in the right direction. Guys that paid attention in Physics class and could recite equations off the top of their heads. If you could get them talking they had great stories of one problem or another and how they tackled and fixed them. Not now (now I'll sound "old"). Now we have "engineers" (small e) that can't solder (I myself am proud to say that years back I passed HP's soldering exam for mil-spec hand soldering- you "used" to put this on your resume!), can't spec, don't read data sheets, build stuff that ON PAPER won't work, build everything from "demo" and "eval" boards - I could go on and on. If you talk to them about component level trouble-shooting their eyes glass over... it really is a sad state of affairs.
Last year I tried to start an "electronics club" locally. After four months there were three, yes 3 people that showed interest...
And don't get me started on e-waste and the "no lead" thing... lookup "tin whiskers" if you want to get a good picture of where we're headed on e-waste...
I was working outdoors, in my backyard, near a friendly neighbor who had pulled the transmission out of his daughter's used car, to repair it. He was doing it himself to save $. I called over the fence and teased him sayting, "You don't know anything about rebuilding transmissions!" Without missing a beat he replied, "I'm at least as good as the hung-over high school drop-out, that assembled it in the first place."
The next day I saw him drive by in that car.
My best resurrection was to a magnetic wire recorder, that predated tape recorders in the late 40's and early 50's. It was a console model that could record from microphone or AM radio, and it could play 78rpm records. I was asked by my grandparents if I could get it working, because it had several precious memories on it, such as the time my grandfather's barbershop quartet sang on the first day of broadcasting, of a radio station in their hometown.
I was able to get it working (just bad tubes), but had to resort to using a variac transformer to feed greater than 110Vac to the drive the motor, to compensate for the friction in the worn-out transmission. (I tuned it by listening to the pitch of my dad's voice, on one of the recordings.) Of course I had to cobble it together with about 5 fans aimed at it, to keep the motor and drive train from overheating, due to the higher-than rated voltage.
Worked great, and held together long enough for me to dub all the wire recordings over to to cassette tape. Copies of those tapes were a great hit at the next family get-together.
Cool! I remember years ago as a kid, someone wrote a letter to Popular Electronics asking if there was a way to convert a wire recorder to a tape record. The editor's response was, "Short of being brutal about it, no." The cartoon above the letter showed someone hammering wire on an anvil to flatten it. That image has stuck with me all these years!
I find having the techical background that I do makes a good combination with being a chea... er, "economically cognizant" individual such as myself. I have a habit of occsionally "rescuing" vintage technology from front-yard "landfill departure lounges". My best neighborhood find was a Heathkit AA29 Hi-Fi amp, from the 70's when Hi-Fi meant business (and specified RMS power actually equalled the heat coming off a large resistor load!). It literally became a rescue, as the downpour that opened up just as I got home with it would have destroyed its lovely, nearly spotless walnut case. Several domed electrolytics revealed the key fault, and after an investment of less than $10, I had me a decent 120W power-amp which I presently use as a sub-woofer driver in my LCD TV setup. Using a self designed and constructed Triac based AC switch power-bar, controlled by the TV panel's USB port, I can leave the AC switch of the amp ON and have it controlled automatically with my TV.
Today's LCD monitors are freqently discarded for trivial reasons. Two 20 inch Dells at work needed (1) replacement SMD fuses and (2) $5 in replacement electrolytic capacitors. Both are serving my family well.
Then again, unavailable schematics don't help. Otherwise I would have replaced the $1 FET in my Toshiba laptop years ago when it died. But I finally got the schematic and now it works fine too.
EE-ing: more than just a job!
I continually meet "EE"s who are so specialized that they can not understand anything outside of their special field. An example was one who was a whiz at FPGAs but either could not (or would not) deal with anything that was not "1"s or "0"s.
By the way, I still have a Heath Kit stereo that I built during my senior year in college (1959-1960). The only major failure, other than tubes, has been an electrolytic cap in the plate supply. It still sounds great.
Oooh! Nice catch on the 36" LCD TV! And you're lucky to have a wife who would actually bring home a "electronic junk" for you to play with! :-) I've also repaired numerous CRT monitors, LCD monitors, vaccuum cleaners, and other products that were discarded by the owners because they didn't work. For me, I get the satisfaction of solving an interesting trouble-shooting puzzle, getting something for "free", and saving a product from the landfill, for a few more years.
It amazes me the mentality of consumers today. We've been programmed to believe that anything that is broken belongs in a landfill. Products only need to last the length of the warranty and then they are discarded. Luckily, I've convinced family and friends that this is not true. I routinely get items with the caveat, "I know it's broken but I figured you might want to look at it before I buy a new one".
Like Tombo, I have the attitude that you can't break it any more by opening up something that's already broken. I'm able to repair between 70% & 80% of all the items I receive. The remainder are usually damaged beyond economical repair.
Though I've never had buzzing from a bad cap, you can bet I'm filing that info for future use.
This thread got me thinking about all the things I've fixed over the years. One was a Sankyo tuner/amplifier in the late 80's. A friend worked at a restaurant. One day he showed up with the amplifier and said "it worked the night before; we turned it on this morning and nothing It's yours if you want to mess with it". I made sure they didn't want it (they had already bought a new one). It came on, all lights but no sound. I said to him "at the end of the night you just turned it off and this morning "just" turned it on"? "Yup". You can see where I'm headed; first thing I thought was "they had it up loud at the end of the night, turned it off and this morning just turned it back on without turning down the volume - has to be a fuse in the output section". Sure enough, got the cover off and both output fuses were blown. A trip to Radio Shack and 79 cents later I had a new receiver. I took the front panel and knobs off and gave them a good scrubbing in the sink (restaurant guck). I used that receiver until I bought a 5.1 system in the late 90's. I also learned the lesson to ALWAYS turn an amp down before turning it on. I play guitar and have seen many amps taken out because of this as well.
The physics department at my college had a problem. Their PA amp had failed a few hours before a prestigious physics guy was to talk. At least 3 graduate students had "worked on" the amp, the fuse, I was told, was replaced three times! I said, "you're out of fuses now, right?". Yes, they were. You are probably guessing what was going on. They had 5 amp fuses, (or at least had had them) but no one knew what "SB" on the fuse rating meant. But I did... Indeed, you can't replace a slow blow fuse with a fast-acting one and expect everything to just be ok, right?
That sounds veeeery familiar to me... "Has to be quite easy to repair, because it worked fine. Just today it devided not to work, but used to work fine... so it has to be easy to repair..." :-)
The only difference between your friends and mine is that my friends want the gadgets back once repaired... bad luck for me!
And talking about capacitors... just for your info, Windows is not always guilty for the system hanging. Replace the capacitors and you'll restore many motherboards...
I love hearing about other old guys like me who like to fix things instead of replacing them. I'm a yard sale junky; I've picked up numerous pieces of high end audio and video gear (not to mention tools and test equipment)for next to nothing. Usually there is nothing wrong that a little contact cleaner and/or WD40 won't fix. I got started in this industry repairing radios and TVs in the early '70s (when lots of stuff still had tubes in it) I learned how to spot and smell an over heated resistor or a bad capacitor. Too bad no one can make a living doing repair work anymore.
It's true, the younger generation has no clue; we had a kid work here who was a computer whiz, but had no clue that there were switches inside a computer mouse. I don't think he even understood the concept of a switch.
Everybody is certainly correct about the "replace it" mentality that has become embedded in so many people. The sad reality is that some time back many companies decided to stop making products worth repairing. The other problem, of course, which is much worse, is that so many individuals represent that they are capable, but they don't know anything except how to write "not repairable" on a tag, then sell a new appliance, or whatever. I have repaired about 20 dead VCRs by simply opening them and taking them apart far enough to clean the mechanism with a "Q" tip and alcohol, then putting them back together. That makes them work. Many folks find my repair technique amazing, but who can argue with a very high success rate. Of course, poor solder connections and hidden fuses also can be the source of many "unrepairable" evaluations.
==== The sad reality is that some time back many companies decided to stop making products worth repairing. ====
I'm not sure if companies actually "decided" that. I think what actually happened is that the cost of buying a replacement part has dropped dramatically, due to efficiencies in product design, improved manufacturing methods, and of course, off-shoring. Just think about the complex consumer products that you can buy nowadays, in terms of your hourly salary, compared to similar products 20 or 30 years ago. The cost of many consumer products has dropped relative to inflation, while the cost of repairing anything (parts + labour) has increased with inflation.
The yardstick I use is the colour TV. When we bought our first one, in the late 1960's, the price was in the $700 range, and minimum wage was less than $1. These days, you can buy a 32" flast-screen LCD TV for $200-$250, and minimum wage is around $9 here in Canada. If TV prices had risen with inflation and minimum wage, the LCD TV would cost $6300, and for sure it would be worth repairing.
LG flat panel TV goes into standby after running for 3-4 minutes. Repair man $70+ just to look at it dianosed as SMPS fault, beyond economic repair. Cure..remove back panel, clean fluff out of fans so they now actually rotate...and reassemble!
Ah yes! The "early shutdown" problem! How many times over the last 20 years have you heard "my computer runs for about (fill in time) and then shuts down". Open the case and you'll see what looks like a brown wad of cotton where the processor fan should be... I have a stack of what were at one point very expensive machine servo amplifiers. I grabbed them from the trash figuring I could use the cases, transformers etc. in "something". I opened one and thought "this is an odd thing; they lined the case with felt". Once I started digging away at it I realized it was compacted dust! The heat-sink and fan, entire inside of the case was loaded with dust. If the guys doing PM had thought to clean the amps from time to time they would most likely still be in service today. A few years ago a neighbor said his garage door opener needed to be replaced; it was intermittent and the door company said the whole thing would have to go. Given the "it can't hurt to open it up" thinking I opened it up and pulled the main board. A CEM-1 PCB and all through hole parts. A quick look around and guess what? The main connector with the antenna wire dangling and connection for the button had cracks across it. The traces were barely hanging on. A bit of solder across the traces with some jumper wires and everything worked perfectly. Saved him $800.00 on that one (though I'm sure the garage door company didn't appreciate it).
Those of us who can fix things (I'm a 64 year old ME with EE grad work) are lucky but one point not made above is the incredibly high cost of commercial repair shops. In most cases "paying" for the repair of a consumer product will exceed the cost of a newer (and possibly better)replacement. Plus most shops charge a fairly steep fee to provide an estimate: It might cost $95 to get them to tell you it will cost $300 to repair a TV that you can buy a newer (and better) version of for $299. So, you really can't fault the non-technical consumer for making the best decision for him. If I can't fix it I'm not going to pay someone else $95 to tell me it's not worth fixing.
By the way - for the TV that started this discussion - a good solution for someone who did not have the expertise to actually repair it would have been the addition of a sound bar. Most offer s/pdif input and most new TV's have s/pdif output (usually Toslink). Many are in the $100 to $150 range so less than a commercial repair would cost and the sound is an amazing improvement over most internal TV speakers. My company manufactures a s/pdif audio delay for lip-sync correction in home theater systems. The DD740 normally intercepts s/pdif audio between sources like DVD players, DVD's, etc. on the way to the receiver/amplifier but for customers who don't use a surround sound receiver we often recommend a low cost digital sound bar so we can intercept the TV tuner's audio. Otherwise it stays internal going directly to the TV's amplifier and speakers (where the capacitor failure caused the amplified noise).
What brand and model flat panel TV?
I hope this is the exception not the rule for flat panels or we will all be using your example to fix our own flat panel TV's.
This is what happens when bean counters move engineering off shore without experence continuity.
Any real designer knows that you MUST derate SMPS capacitors by ~50%. (all caps need to be derated in any application, especailly electrolotics, and tantalums.)
I seem to always find the courage to open electronics that have failed on me prematurely, my problem is to determine when is time to call it quits, after you spend several hours in tear downs, replace and retest efforts.
It is hard to walk away from an investment of time and effort.
Does any one have a piece of wisdom that your willing to share, when is time to stop and recycle?
That IS the hard one to call, Rene. Basically when you don't think you'll get any further. Which will be a lot futher down the line for you in your garage than for a repair shop. The problems these days are (1) it's almost impossible to get service sheets and (2) unless you're kitted out for it, SMD components are very difficult to change.
But I reckon 90% of LCD / Plasma TV failures would be through-hole electrolytics which are easy to fix. I suspect a repair shop could do good business with these on the following basis:
- No quotes,
- If we fix it easily it's (say) $75.
- If we can't fix it easily, no charge
- If we reckon we can fix it with a bit more effort / parts etc, we'll quote, you can call it quits if you want.
I reckon you'd make enough on the ones with blown caps to cover your time on the others.....
I am trying to remember what are the main failures of the LCDs we have repaired over the years... And I can tell you that usually its the inverter. Either some transformer is shorted or some other circuitry has failed.
I can't give you numbers because our management software doesn't allow us to categorize the repair work we do, but I think its less than 50%.
Yes, there are some LCD models that seem to have to some design flaw because most of them have bulged capacitors.
About the repair shop costs:
I agree with you about the way a repair shop should run its business.
As does my father that for more than 30 years as been doing exactly that.
There just one small difference: we can't give a quote, in most cases, without actually repairing the appliance.
However, we don't have employees therefore we don't have fixed costs.
And that makes all the difference; that's why most repair shops charge money to give a quote.
They can not afford to have on technician working all day on appliances that won't be repaired because the customer says it too expensive...
Just re-read this article after it was linked to today. Since my post above I had a similar case - a 42 inch plasma that was in a skip. I opened it and found the usual bulging caps. But that's when my problems started. They were as I recall 680uF at 400 volts. Not an easy cap to find. And to add insult to injury, some of them were under a part of the frame and could not be more than about an inch and a half high. Armed with these specifications I started to search...
I could get the right ratings - only in an 85C cap - but they were too high. I could get the right size, right capacitance, but only 250 Volts. I could get the right size, 400 V and 105 C, but only 250 uf.....and so on. Eventually my boss (this was at work) told me to get it out of the workshop or put it back in the skip. With a heavy heart I did the latter. I consoled myself with the thought that plasmas are kind of old technology now and it would have only added to my power bill, and it only had an analogue tuner so I'd have had to get a set-top box for it.
And my boss had the thrill of seeing me throw something in the skip. Which does not happen very often :-)
A Book For All Reasons Bernard Cole1 Comment Robert Oshana's recent book "Software Engineering for Embedded Systems (Newnes/Elsevier)," written and edited with Mark Kraeling, is a 'book for all reasons.' At almost 1,200 pages, it ...