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Old 2nd Sep 2020, 11:08 pm   #61
IKC2E51R8
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

Better look at the circuit diagram including the horizontal section
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Old 2nd Sep 2020, 11:22 pm   #62
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

If you had either no line drive (faulty line drive transformer etc,) then you would have neither EHT nor any line scan at all with a set of this age and vintage therefore no white line at all in any direction.

You are likely reading across the line driver transformer itself through various paths.

I need a better, bigger diagram to see though, can you post the full PDF ?
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Old 2nd Sep 2020, 11:34 pm   #63
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

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Originally Posted by Red to black View Post
If you had either no line drive (faulty line drive transformer etc,) then you would have neither EHT nor any line scan at all with a set of this age and vintage therefore no white line at all in any direction.

You are likely reading across the line driver transformer itself through various paths.

I need a better, bigger diagram to see though, can you post the full PDF ?
What about the lack of continuity on the primary on the transformer, is that a problem?

where else should I be looking at for this issue, there's still 0v coming off that feed resistor for the vertical and the resistor is good

I have a manual for this chassis but its not the same model of set, mine is a Dansai 9313A and ive a manual for a Roadstar CTV1424 using the GT9313 Chassis. I'll add the PDF here

Thanks for all your help so far, I really appreciate it
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Old 2nd Sep 2020, 11:42 pm   #64
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

Since the transformer works, the lack of continuity must be a faulty measurement. Since you get a horizontal line, the fault would be in the vertical deflection.
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Old 2nd Sep 2020, 11:46 pm   #65
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

I can't immediately see where the path you are reading across the C-E of the line driver transistor is coming from but probably via the 110V supply.
Try your multimeter on a higher resistance range to measure the primary side of the line driver transformer, the range for continuity maybe too low to measure this, not that the reading matters as such, as already said if this stage wasn't working you wouldn't have any EHT or scan at all on this set.

It is getting late for me (up at 5am) so I will have a closer look for you tomorrow.
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Old 3rd Sep 2020, 12:00 am   #66
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

Thanks, i was thinking the horizontal definatly has to be working, just wanted to be sure though cause those readings i got confused me. there something else going on with the vertical, going to buy a few new 0.68ohms resistors just in case that replacment resistor actually has gone open as a result of whatever other component is at fault.
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Old 3rd Sep 2020, 2:42 am   #67
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

So I found D407 was fried so changed it and i found another resistor for the feed and changed that, started the set up and heard deflection for all of a second before a crackle, burning smell and the tinyiest amount of smoke from the feed resistor then just the horizontal line.

did some checks and the frame IC is toast with a little scortch mark just above pin 4 which is a ground pin, the whole IC has continuity now along with every component in the vertical circuit and R408 has gone open. Cant remove the IC as my desolder pump decided to randomly disintegrate while i was removing the resistor the last time (never buy a €6 desolder pump on eBay )

Now i need a new Frame IC and possibly some other parts, in fact i might just order everything in the vertical circuit (that I dont already have new) and replace the lot and be done with it.
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Old 3rd Sep 2020, 10:14 am   #68
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

It was actually Pin 6 of the IC that blew and has the scortch mark, may or may not help pinpoint where this fault is coming from
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Old 20th Sep 2020, 1:39 am   #69
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

Hi Everyone

I've changed everything in the vertical circuit. still nothing, just horizontal line (G2 up), here's the voltages from the IC if its any help to decipher whats going wrong

Pin 9 = 25.9v (Supply)
Pin 8 = 0v (Flyback Generator)
Pin 7 = 6.0v (Guard Circuit)
Pin 6 = 25.5v (Output Supply)
Pin 5 = 24.2v (Output)
Pins 4,3,2 &1 all 0v (Ground 2 & 4. Drive 1&3)



There's 6v on Pin 7 (guard Circuit) reading the datasheet for the TDA3653B it says when the voltage on pin 8 drops below 1.8v a dc voltage will be produced on Pin 7 blanking the screen. this seems to be happening but I don't know why.

can anyone help me
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Old 20th Sep 2020, 5:30 pm   #70
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

Hi I don't know if this will help but looking at the datasheet for TDA3653B, the vertical drive comes from the horizontal (jungle) chip in the form of a ramp, which if missing will result in the loss of vertical scan. If you have a scope look on pin1 and 3 for a 50Hz ramp. If missing you will need to fault-find the preceding stage. It might be a TDA2578A as these two chips 'go together', but I don't have circuit information on your set so it is something of a guess.
Sorry if I've led you astray.
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Old 20th Sep 2020, 6:56 pm   #71
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

Hi

The Jungle IC is a TDA8361, I dont have a scope unfortuantly but all signs seem to be pointing to the Jungle IC being at fault, I've replaced every component in the vertical output stage, the voltages going to the Vertical Output IC are correct, It seems that all thats missing is drive which comes off Pin 43 on the TDA8361, wish I had scope just to confirm.

I Have a TDA8361 spare that I could use, I've been putting it off hoping it wasnt that (I hate soldering larger IC's, tiny pads and a crap soldering iron make it a long process) Im going to change it anyway and fingers crossed that's the final piece to this puzzel.

It surely couldnt be anything else could it?
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Old 20th Sep 2020, 7:01 pm   #72
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

Part of where you need to be careful here is the classic "chicken and egg" scenario, in that if the jungle/driver chip doesn't get the correct feedback signal it is expecting then it shuts down its drive, this can be very difficult to sort out.
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Old 20th Sep 2020, 8:04 pm   #73
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

Quote:
Originally Posted by Red to black View Post
Part of where you need to be careful here is the classic "chicken and egg" scenario, in that if the jungle/driver chip doesn't get the correct feedback signal it is expecting then it shuts down its drive, this can be very difficult to sort out.
The Feedback should be correct though shouldn't it seeing as I've replaced all the components on the feedback line?
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Old 20th Sep 2020, 8:51 pm   #74
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

Changed the TDA8361, same result.
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Old 23rd Sep 2020, 5:16 pm   #75
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

In post 45 you said
Quote:
new problem, my meter slipped when checking the voltage on D405, dont know what it hit, probably the horizontal line pin, there was a sqeak and the set shut down, it comes back on but no pic, standby led dimmer than usual, Ive got a horizontal line if i turn up the g2, no 26v coming off Pin 5 of the flyback for the vertical. 110v going into the flyback at Pin 3.
Is the standby LED still dimmer than before your probe slipped? If so, is the 5 volt line that feeds the Standby LED OK? I am assuming the circuit in post 63 is correct for the electronics in your set.
Keep at it.
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Old 23rd Sep 2020, 5:26 pm   #76
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Default Re: Help With Vertical Circuit. Capacitor getting extremely hot

Quote:
Originally Posted by G8vsjDave View Post
In post 45 you said
Quote:
new problem, my meter slipped when checking the voltage on D405, dont know what it hit, probably the horizontal line pin, there was a sqeak and the set shut down, it comes back on but no pic, standby led dimmer than usual, Ive got a horizontal line if i turn up the g2, no 26v coming off Pin 5 of the flyback for the vertical. 110v going into the flyback at Pin 3.
Is the standby LED still dimmer than before your probe slipped? If so, is the 5 volt line that feeds the Standby LED OK? I am assuming the circuit in post 63 is correct for the electronics in your set.
Keep at it.
Dave
Hi

No the Standby LED is normal now, the manual that i posted is as close as i could find to mine, theres 5 different manuals for this chassis (seems theres different variations of it all with the same name GT9313) some of them list different value components to what was originally in the circuit (for example: C434 in the manual is 220uf 40v but in the set was a 470uf 35v) I think i may have two of the resistors in the feedback wrong value, R417 in the manual is a 100K but turns out when i went back over the parts i removed its actually a 120K that was fitted and R420 was a 2.2ohm not a 1.5ohm.

Im going to order those correct resistors and see if that helps as was suggested if the feedback the jungle recieves is wrong the drive will shut down, i think thats whats happening.

I'll keep at it until I get it
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