Mtc9000 ? I think ..

[Retroman839]

I will try rhat again
Last time.. It was out of stock

Also does that require a bench meter ?
Some have a built in meter

Order submited ..

 

[Retroman839]

polarity don't matter on those caps
the reason I dummy load at the HOT collector first is to see if there are any shorts in deflection circuit, all you did was prove b+ is ok
i would not be too confident in that flyback either as i know where its from
Do you have an eht probe so you can see if you get initial HT and what level it is?

So C36 low or open circuit ..
Guess I’m gonna need a new one of these .

 

[M K L]

When that cap fails, it causes the HV to spike and the x-ray protection quickly shuts off the H drive pulse from the TDA2595. But we have seen this early version doesn't have the protection circuit so I'm wondering what is shutting it down...

 

[tb2000]

I could be wron but I think you'll find the capacitance of those poly caps is too low for the Peak to pick up anyway.

 

[big10p]

I could be wron but I think you'll find the capacitance of those poly caps is too low for the Peak to pick up anyway.

Think you're right. Manual for mine says 0.3uf min.

 

[Retroman839]

When that cap fails, it causes the HV to spike and the x-ray protection quickly shuts off the H drive pulse from the TDA2595. But we have seen this early version doesn't have the protection circuit so I'm wondering what is shutting it down...

 

[tb2000]

Think you're right. Manual for mine says 0.3uf min.

Yeah I check poly caps using my multimeter. Had to get a new one a while ago as my old one went wrong, it's a Multicomp Pro MP730026, seems fairly accurate far as I can tell.

 

[sukhbir]

View attachment 68113
So C36 low or open circuit ..
Guess I’m gonna need a new one of these .

Is that the tuning capacitor Which goes to collector of the bu508?

 

[Retroman839]

Is that the tuning capacitor Which goes to collector of the bu508?

Yes

3n9

So nanaofarad is a billionth
Micro is a millionth …

My meter don’t go that low .


I should just change the cap then.
As it’s integral .

 

[sukhbir]

Yes
View attachment 68135
3n9

So 3.9 nanaofarad is 0.39 ohms?

I think you have found the culprit.

 

[Retroman839]

polarity don't matter on those caps
the reason I dummy load at the HOT collector first is to see if there are any shorts in deflection circuit, all you did was prove b+ is ok
i would not be too confident in that flyback either as i know where its from
Do you have an eht probe so you can see if you get initial HT and what level it is?

I

I think you have found the culprit.

if i can find a replacement I can test with a known good 4n7 1500

 

[tb2000]

3.9 nanofarads or 0.0039uf. Or 3900 picofarads.

 

[Retroman839]

Good work , 👍

Can a replacement cap be recommended pls , don’t want to get the wrong value part .. I’m having fun looking all the same ..
but just realized I was seeing 300v as 3000v !

 

[tb2000]

A 4n7 1.5kv or 2kv will be fine (or 3n9) as you mentioned above. I was just pointing out what the values were.

 

[Retroman839]

D

A 4n7 1.5kv or 2kv will be fine (or 3n9) as you mentioned above. I was just pointing out what the values were.

Thanks 👍I will try to get my head around
The math on that .. impressive .
how it is that you can write .. from one millionth to one billionth in so few zeros ! 🤣..Thanks 👍..
is that ten to the power of minus three ?


And for that replaemt cap 4n7 1500. High pulse polypropylene ? Mkp or fkp

 

[Retroman839]

I found these

https://ebay.io/m/jEDJ4K

Or these

https://ebay.io/m/xk9MY8

Or this type

 

[Retroman839]

I don’t know why apart from
in experience in knowing what to look for.. but it jumped out at me right from the start .. but I just assumed it was factory .. but now I think I’m just looking at a failed flyback.

With a swelling that’s accumulated into a pop releasing it’s electrolytic fluids .. leaving like a mini volcano

 

[Retroman839]

 

[tb2000]

Just looks like a drop of glue to me. See if you can pick it off gently, if there's a hole underneath then you've got a problem. Any of those caps will do the job, as long as the pins are the right pitch for the holes in the chassis (otherwise you'll need to modify them a bit to fit).

 

[Retroman839]

Can I check primary /secondary
To Gnd for short across pins on the flyback now it’s out