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Author Topic: vcr power lag  (Read 2955 times)

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ketske

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vcr power lag
« on: March 26, 2013, 18:43:54 PM »
Hello guys!

Im back again after a few pulse control projects with 555's.

I got an recorder from a friend and .
He hasn't used this about three years, now he doesn't start up from the first time.
When i stick it up to the current a couple of times , then it would start up finally.
I noticed that when i stick it up to the contact something is buzzing like a  baloon , really high pitch sound but really soft  and short.
I noticed that this would came from the spool/transfo or the transfer resistor.
And everything is fine when he starts the way it must be .
So actually i think its the transistor. That the contact between base and emitting/collecting is not functioning properly.

Well, its maybe a shame that didn't already checked the current there, because its not connected with lines like a print, but with sorta tin wires.
I checked the capacitors , all good.
But its really in the spot of the power supply, the fuse is fine , some black on a resistor and a ceramic cap, but its fine !


Annyone some expirience with these sympthoms?

Thanks!

kam

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Re: vcr power lag
« Reply #1 on: March 27, 2013, 12:51:31 PM »
I had once this problem with a cassette player. It was not used for long long long time.  When i plugged it in, i had this weird oscillation at the output. Only after i replaced all electrolytic capacitors did it worked. As a matter of fact, replacing the aluminum capacitors is a good practice for old electronics. These are the parts that wear out first.

cheerio

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Re: vcr power lag
« Reply #2 on: April 02, 2013, 19:31:12 PM »
i can back kam here. replace the eletrolytic caps. they dry out over time and really old hardware is way over the planned life time.

ketske

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Re: vcr power lag
« Reply #3 on: June 23, 2013, 15:29:18 PM »
i can back kam here. replace the eletrolytic caps. they dry out over time and really old hardware is way over the planned life time.

Sorry for the late post .
But thanks guys!

Actually  weird but right , after some couple times i swapped it into the contact it works fully again !  :o

So i think its was actually the ... wearing of the vcr.
actually in principal just like u guys said , time for some new components .
But however if it gives his soul i think its time for a combi !  :)

this can be closed!

Sir N

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Re: vcr power lag
« Reply #4 on: June 25, 2013, 05:49:01 AM »
Hi,

Actually  weird but right , after some couple times i swapped it into the contact it works fully again !  :o
You "massaged" the electrolytic caps a bit, so now they somewhat work, but this is usually not a lasting cure unfortunately - for a quick(ish) check, remove the mains for 2..3 days and reconnect to see if it returns.

Fastest solution would be to check all electrolytes with an ESR meter, but it's not a gizmo found in every electronicus' tool set.

Hope for the best, but don't be too surpriced if the problem reappears.