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VCR Dead after Thunderstorm...

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Klabbis

New Member
Hi!

After a nasty Thunderstorm my VCR won't start again (not a single sign of life when im trying to turn it on.....).. :cry:
My question is if any of you know what components are most likley to have been busted by the Thunderstorm?

(It's an old VCR so Im thinking of fixing it myself.. but I have never "fixed" anything like this before)..

I have pretty solid knowledge about electronics in theory.. but not in practice....

/Markus
 

Klaus

New Member
You say that you are good in electronics theory, here's your chance to apply it in practice. Before you do, keep in mind that mains voltages are LETHAL, in other words, you can get killed by poking about carelessly inside your VCR's power supply.
Now, consider how the lightning strike's surge spike got into your VCR? Through the power cord most likely. So, first thing to check is if there is power at the wall socket. Next, does the power get into your VCR? - check at the switch. Is there a blown fuse inside the power supply? - check it.
If you have mains power going into the unit, check if low voltage DC power comes out of the power supply. If so, you might as well take the unit to a professional for repair (if its worth it) as you will be able do do nothing more without the circuit diagram and the knowledge to interpret it.
If your VCR's power supply has gone and it is an old style with a transformer you might be able to fix it. If its a new switch mode power supply you'll need the circuit diagram and special knowledge, they can be tricky to fix.

BUT, before you poke around with your meter probes, UNPLUG the unit, remove the covers and use your eyes and nose to investigate. Do you detect a faint smell of burned components? (this would not work for smokers - they lost that sense). Can you see charred components? sometimes you have to look very very close with a magnifying glass to see cracks or little craters on these. Do you see vaporised PC tracks? Only if all looks pristine and working like do start measuring things.

Good luck

Klaus
 

Gene

New Member
Since you trace the problem to an electrical storm, there is a good possibility the the problem started with a power serge coming in the power cord. Also, since you say there is no sign of life (I an assuming that means no lights/clock glowing), this points to the power supply as the first area to look. This can be a dangerous area because there are (or should be) high voltage here.

Carefully start at the area where the power cord enters the unit. Look for a fuse and test it. This could be the only problem. If you can't find one, you will have to go inside. There should be a fuse somewhere. If you have mains power (110 volts AC in the US) continue through the power area. Look for signs of a blown component (black and sooty) - especially resistors. The next area I would check is the rectifier - you should have AC going in and DC coming out. If your user manual came with a schematic, tracing voltage will be much easier. If not, you can use your "solid" knowledge of electronics to trace through until you find a point that should have power but does not.

3rd time - be VERY careful.
 

Klabbis

New Member
Thanks!!

I'll give it a try! And don't wory I'll be VERY VERY carefull...
(I have big respect for high voltage..)
 

stevez

Active Member
I lost a VCR to an electrical storm. I called the cable company to ask a few questions about how to prevent it from happening again. A technician stopped by and found that the point where the cable was supposed to be grounded wasn't grounded. We fixed that problem. He said that usually when someone looses a VCR during an electrical storm that is usually the problem. The info might help prevent another problem. If yours was connected to a cable it might also give clues as to where to start looking.
 

Klabbis

New Member
Thanks again. I'll be sure to investigate that to...
I'll let you know if i ever get it upp and running again

Just one more question... Let's say I have to do some measurements while connected to the outlet (220V ac here in Sweden). I have read somewhere that I should have thick rubber soled shoes and one hand in my pocket as an added security measur when dealing with high power.. although It's a bit hard to do any measurment with only one hand...

Is this true or nonsense? I guess the one hand thing is good... So the current doesn't go through the hearth.
 

kizzap

Member
Klabbis said:
Thanks again. I'll be sure to investigate that to...
I'll let you know if i ever get it upp and running again

Just one more question... Let's say I have to do some measurements while connected to the outlet (220V ac here in Sweden). I have read somewhere that I should have thick rubber soled shoes and one hand in my pocket as an added security measur when dealing with high power.. although It's a bit hard to do any measurment with only one hand...

Is this true or nonsense? I guess the one hand thing is good... So the current doesn't go through the hearth.

i would have to say that the best way to check a power outlet is to plug in something like a light or a fan into it. if they work then the socket is still working. I don't know but i think multimeters have to have a special catagory to be legal (and safe) to test mains output. but good luck and don't get killed
 

Phasor

Member
I have read somewhere that I should have thick rubber soled shoes and one hand in my pocket as an added security measur when dealing with high power.. although It's a bit hard to do any measurment with only one hand...

In the power distribution industry, we regularly work on live mains, with the aid of a pair of insulating gloves. It does, however, result in some loss of dexterity.

Actually, our company rules used to state that you "must wear a pair of insulating gloves". Some smartarse decided that he was going to wear BOTH gloves on ONE hand. So they had to change it to "you must wear an insulating glove on EACH hand" :lol:
 

Klabbis

New Member
Hi again!

The error seems to be in an regulator IC (u4614b) that needs to be replaced. But since my VCR is an old peace of junk I think I'll just buy me a new one.

Well... Atleast now I have some spare parts to desolder.
+I made my first "hands-on" experience.


Well... see you later...

(okej.. lets se some funny posts about "hands-on experience" :) )
 
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