Discharging a CRT TV

[sam67]

Just picked up an old Hitachi color tv that has been stood maybe for a couple of years ..The tv works but i have not plugged it in ..I want to gut all the components out of it i. e pcb and desolder some of the the parts for practicing with.

My question is even though it has been stood so long i was gonna discharge the crt with an insulated screwdriver with a wire with alligator clips attached and ground one end while touching screwdriver under anode cap just to make sure theres no voltage lurking ..Then i was gonna use multimeter on big caps before i desolder them ..Once this is done can i desolder all the parts from power supply side and everything else without any problems.

Seems a shame to dump the tv when i can use the parts for testing rather than going out buying parts while i am learning Reason for tv not been used is it is no good over here now everything has gone digital ,plus it was just in a spare room doing nothing.

Cheers

[mockingbird]

Re: Discharging a CRT TV

I don't know about dischargind the caps, but this is how to discharge the tube:

1) Take a flat-tipped screwdriver and a solid thick wire.
2) Coil the wire around the screwdriver tightly so that they make good contact
3) Attach an alligator clip to the end of the wire
4) Attach the alligator clip to the spring which goes along the left side of the tube next to the Aquadag.
5) Touch the flat tip to the metal clips underneath the suction tube. You should hear a pop.

With a TV that is old, you will have to discharge it many many times until you hear no more pops. Wait a half hour in between discharges. Some here have mentioned that it it impossible to fully discharge a really old TV.

Interestingly enough, I have so far discharged only two newer TVs with a recent manufacture date, and eventhough they have been used extensively, the tubes on them for some reason never kept any significant charges.

[sam67]

Re: Discharging a CRT TV

Thank you for the tip ..Will do it later on .

[stj]

Re: Discharging a CRT TV

if you dont want the tube then why bother discharging it?

the cap has two prongs under it, going right&left.

if you hold the back of the cap with thumb & finger and push it sideways one side will unhook.
then lift a little and move it the other way and it will be off.
the transformer doesnt hold any charge.

wear rubber gloves if your unsure - and *dont* hold anything with the other hand.

[sam67]

Re: Discharging a CRT TV

Cheers guys ,

Got the pcb out last nite with out any problems..This set is over 20 years old lol even the caps still look good ..dropped the pcb though and cracked it never mind i only want it for practicing purposes


Will try my new ESR meter out that i got off Mike the micro v4 see how the caps are after all this time. Must say that mike does not mess about when sending stuff and he is a pleasure to deal with..Highly recommended and great communication from him.

Thanks once again Mike.

[stj]

Re: Discharging a CRT TV

how much was the mk4 inc post to the u.k. ?

[sam67]

Re: Discharging a CRT TV

Hi stj ,sorry for late response only just seen post ..£47.85 inc p+p..

Quick question as it saves me posting another thread.. I have some caps that i have been measuring and then checking with data sheet .. say for example 1000uf 16v with a 20% tolerance is this tolerance already worked out on the data sheets or does it have to be added ..as i measured some caps that were 1000uf 16v that were 0.18 with esr meter and when checking manufacturer data sheet the caps should be 0.16 just wondered if data sheet leaves you to work the tolerance out ..I know it may sound like a dumb question but just wondered while i am learning using the data sheets correctly.

Thanks in advance.

[sam67]

Re: Discharging a CRT TV

Should have said that the price was $75 and the price in pounds at the time was £47.85 when i bought mine the exchange rate was not as good. Best to contact mike .

[sam67]

Re: Discharging a CRT TV

Forget the question regarding the tolerance as i had a dumb moment and was thinking that the tolerance was for the esr when it should have been for the uf lol.

[Radio Fox]

Re: Discharging a CRT TV

...Will try my new ESR meter out that i got off Mike the micro v4 see how the caps are after all this time. Must say that mike does not mess about when sending stuff and he is a pleasure to deal with..Highly recommended and great communication from him...

Did your ESR-micro V4.0 have the batteries already fitted?

My meter arrived this morning, but with no batteries. I'm not complaining, it's just that, if I knew in advance that batteries were not included, I would have bought some beforehand.

[stj]

Re: Discharging a CRT TV

probably safer not to ship stuff with battery's,
if it goes into a plane then the cargo will get decompressed - the pressure-drop may make the cell's leak!

[stj]

Re: Discharging a CRT TV

double-post!

[sam67]

Re: Discharging a CRT TV

Hi guys ,

No mine did not come with batteries ..Mike did tell me before i ordered as it can cause problems at customs and Mike wanted to deliver as quick as possible without any hold ups..You can get the batteries off ebay really cheap ,that's what i did.

One of the best tools i have bought and the meter seems to be really accurate so no complains from me and a big thumbs up to Mike..I am a beginner in this field as i have already stated but devices like these really do help whether you are newbie like me or professional..

I am also looking at his Fly back tester ..but i am still finding my way around and learning as much as i can let my brain take lol.

[stj]

Re: Discharging a CRT TV

i made my own flyback ringer using a schematic.
http://members.ozemail.com.au/~bobpar/fbt.htm

[Radio Fox]

Re: Discharging a CRT TV

Hi guys ,

No mine did not come with batteries ..Mike did tell me before i ordered as it can cause problems at customs and Mike wanted to deliver as quick as possible without any hold ups..You can get the batteries off ebay really cheap ,that's what i did...

Didn't have time to shop around. I wanted to play with my new toy straight away

Just come back from my local supermarket. Luckily they had some Energizer 2032 batteries (£1.80 each).

[sam67]

Re: Discharging a CRT TV

I got some maxwell 2 lots (4 Batts) for £2.18p inc p+p off ebay but like you say you did not want to wait.At least you can have a play about though now lol.

p.s just checked my ebay purchase .

[stj]

Re: Discharging a CRT TV

99p stores in the u.k. often have a card of them - for 99p