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Chassis number?

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jts1957
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Jul 21, 2009, 2:18 AM

Post #51 of 98 (1444 views)
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Re: [bogart219] Chassis number? [In reply to]	Can't Post

CX3404 = Probably GOOD (they seldom fail).
QX3402 = Definitely BAD (Shorted). (schematic shows No ID - you'll have to tell us)
R3415 = Definitely BAD (open)(.15 ohm 3 - 5 watts).
R3412M = BAD (burnt/charred/smoked?)(100 ohm 1/4 watt or smaller will work)

Quote

(Resistors and diodes are ok to test like this right?)

Let's try looking at this another way: you have a 10 ohm and a 100,000 ohm resistor, you put each resistor (in turn) across the same "coil." What resistance would you measure? ZERO in both cases! You are measuring the resistance of the "coil," NOT the value of the resistor!
Having said that: if you measure a RESISTOR "in-circuit" and you obtain very nearly the same ("correct") reading with the meter leads hooked up either way, the resistor is most likely GOOD. Drastically different readings (neither within 5 - 10% of the correct value), I'd pull one side and test again. As a side benefit of testing caps and resistors "out of circuit" - you only have to test once, no need to reverse meter leads.
Diodes are easier. With only a couple of exceptions, when tested "out of circuit" (DVM=diode test) they will always give a reading with one polarity of the meter leads and NO reading with the meter leads reversed. The only one of the three diodes you list I can be sure is good is CR3407 (retest others, one side floating).
SMD (surface mount devices) are on bottom of board and schematic says 100 ohms each. Now that you know both are SAME you can easily see the "101" on the good one?
CR3402 is to left of QX3402. Probably under a 3 watt resistor (RX3402).
SMPS = Switched mode power supply.

Pin #10 of IC3401 (current mode controller) to pin #9 resistance? In circuit - no need to float - but test before installing new parts.

-------------------------
Location: Far, Far Away

(This post was edited by jts1957 on Jul 21, 2009, 2:27 AM)

Ron.M
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Jul 21, 2009, 2:22 AM

Post #52 of 98 (1442 views)
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Re: [bogart219] Chassis number? [In reply to]	Can't Post

bogart219:....
I'm assuming you mean the probes are on the top side of the board when you are checking the resistor or diode...
The underside of that board where the resister or diode are soldered has copper foil which acts as wiring...
If you do not unsolder one or more legs of the part you are testing,other parts are STILL connected to the part you are checking thru the copper foil....& can & often DO give erronious readings...
It's best to isolate certain parts for testing...

I do not know how you do this:==>

"""JTS, Here is the latest. <br>CX3404 I would say is borderline. <br> <br>Tested the following components out of circuit: <br>QX402 Continuity on all legs. BAD ? <br>QX401 <br>G to D - continuity (beep) one way, reverse leads nothing <br>D to S - .491 one way, reverse leads, nothing <br>G to S - nothing either way <br> <br>R3415 = (1000k, 1KV), nothing, open. BAD? <br> <br>The following components I checked in circuit. (Resistors and diodes are ok to test like this right?) <br>R3420 = .7ohms <br>CR3418 = .087 beep both ways <br>CR3417= 1.72 one way, .54 leads reversed. <br>CR3407= .481 one way nothing leads reversed <br> <br>""""

BUT that's hard to read...PLEASE avoid it in the future...THANK YOU.... Sly

Sly

..

Hope this helps..... Sly

Sly

....

jts1957:... I LOVE those two graphics you put up...Including the one you had before you did the edit...WHERE did you get those & how did you post them...REALLY COOL!!!!

Later...Ron.M.... Cool

Cool

....
Veteran & Retired TV technician

(This post was edited by Ron.M on Jul 21, 2009, 2:55 AM)

rrobor
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Jul 21, 2009, 7:45 AM

Post #53 of 98 (1418 views)
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Re: [jts1957] Chassis number? [In reply to]	Can't Post

You guys still going on with this banger. He blew up the FET, have we all done that once, sure we have. Now he needs a new FET, a new IC to drive it, probably a zener in its gate and a couple of resistors in its drain. You then have to question the chopper transformer, did that blast through. After all that is fixed, you return to the question of why it took half an hour to show a picture. My guess would be the the TV uses a Philips chipset and its an I squared C problem. The tube wont balance so the picture dont come on. Its as common as Mud, from Philips to Sony to whatever. So does the guy try to fix the supply, spend time and cash doing that or does he cut his losses now. Ill take bets on it that this thing is dead and any more is money wasted. All bets covered except from the poster who could cheat.

bogart219
User

Jul 21, 2009, 12:42 PM

Post #54 of 98 (1414 views)
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Re: [rrobor] Chassis number? [In reply to]	Can't Post

Reposting my previous post again. Don't know how all that garbled stuff got in there.

JTS, Here is the latest. ;CX3404 I would say is borderline.;
Tested the following components out of circuit:;
QX402 Continuity on all legs. BAD ?
QX401 G to D - continuity (beep) one way, reverse leads nothing
D to S - .491 one way, reverse leads, nothing
G to S - nothing either way
R3415 = (1000k, 1KV), nothing, open. BAD?
The following components I checked in circuit. (Resistors and diodes are ok to test like this right?) R3420 = .7ohms CR3418 = .087 beep both ways CR3417= 1.72 one way, .54 leads reversed. CR3407= .481 one way nothing leads reversed Surface mounts on bottom side of board right? Numbers not on board. SMD that has one side going to G on QX3401 (R3418M)? is 98.7ohms. SMD closest to QX3402 (R3412M ?). Not sure on this one. It is solid brown color. There were four other ones throughout the board and they all check the same .1 ohm. The other smd's has resistor bands.
Can't find CR3402. Can you tell me some components its near?
What exactly does SMPS stand for? Thanks! JTS, If I have to test those components again that I did in circuit let me know. I'll lift one leg. Even SMD's?

jts1957
Veteran

Jul 21, 2009, 12:49 PM

Post #55 of 98 (1411 views)
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Re: [jts1957] Chassis number? [In reply to]	Can't Post

And my reply before we became sidetracked (I had read and was responding when his post got messed up):

In Reply To

CX3404 = Probably GOOD (they seldom fail).
QX3402 = Definitely BAD (Shorted). (schematic shows No ID - you'll have to tell us)
R3415 = Definitely BAD (open)(.15 ohm 3 - 5 watts).
R3412M = BAD (burnt/charred/smoked?)(100 ohm 1/4 watt or smaller will work)

Quote

(Resistors and diodes are ok to test like this right?)

Let's try looking at this another way: you have a 10 ohm and a 100,000 ohm resistor, you put each resistor (in turn) across the same "coil." What resistance would you measure? ZERO in both cases! You are measuring the resistance of the "coil," NOT the value of the resistor!
Having said that: if you measure a RESISTOR "in-circuit" and you obtain very nearly the same ("correct") reading with the meter leads hooked up either way, the resistor is most likely GOOD. Drastically different readings (neither within 5 - 10% of the correct value), I'd pull one side and test again. As a side benefit of testing caps and resistors "out of circuit" - you only have to test once, no need to reverse meter leads.
Diodes are easier. With only a couple of exceptions, when tested "out of circuit" (DVM=diode test) they will always give a reading with one polarity of the meter leads and NO reading with the meter leads reversed. The only one of the three diodes you list I can be sure is good is CR3407 (retest others, one side floating).
SMD (surface mount devices) are on bottom of board and schematic says 100 ohms each. Now that you know both are SAME you can easily see the "101" on the good one?
CR3402 is to left of QX3402. Probably under a 3 watt resistor (RX3402).
SMPS = Switched mode power supply.

Pin #10 of IC3401 (current mode controller) to pin #9 resistance? In circuit - no need to float - but test before installing new parts.

-------------------------
Location: Far, Far Away

(This post was edited by jts1957 on Jul 21, 2009, 12:56 PM)

bogart219
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Jul 21, 2009, 12:53 PM

Post #56 of 98 (1409 views)
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Re: [bogart219] Chassis number? [In reply to]	Can't Post

QX402 - writing on chip
M
1190
R403

QX401
M
1189-01
R405

R3415 round disk type resistor
1000k
N2200
1KV

Will get back to you on others

jts1957
Veteran

Jul 21, 2009, 1:11 PM

Post #57 of 98 (1405 views)
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Re: [bogart219] Chassis number? [In reply to]	Can't Post

In Reply To

QX402 - writing on chip
M
121-1190
R403

QX401
M
121-1189-01
R405

R3415 round disk type resistor
1000k
N2200
1KV

Sounds like a capacitor - are you sure? Let's hope we are not mixing up parts!
Will get back to you on others

-------------------------
Location: Far, Far Away

(This post was edited by jts1957 on Jul 21, 2009, 1:17 PM)

bogart219
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Jul 21, 2009, 1:32 PM

Post #58 of 98 (1400 views)
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Re: [jts1957] Chassis number? [In reply to]	Can't Post

Yeah your right, I'll double check that to! Smile

Smile

Ron.M
Veteran

Jul 21, 2009, 11:01 PM

Post #59 of 98 (1396 views)
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Re: [bogart219] Chassis number? [In reply to]	Can't Post

bogart219:...

PLEASE IGNORE POST #53...

He forgets that the ORIGINAL problem was a FAULTY connection on the CRT module & NOT the CRT!!!...
He "MAY" be right about the other stuff,BUT that's NOT been determined yet...
He also fails to understand your personal situation & therefore condems your TV without ANY compassion...

jts1957;...

This is for you;....

Thank You VERY much...
(Need to figure out how to get the white background out.)

Later...Ron.M... Cool

Cool

...

Veteran & Retired TV technician

(This post was edited by Ron.M on Jul 21, 2009, 11:04 PM)

bogart219
User

Jul 22, 2009, 12:42 AM

Post #60 of 98 (1391 views)
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Re: [Ron.M] Chassis number? [In reply to]	Can't Post

Thanks Ron, Sure glad you and jts1957 have some compassion Smile

Smile

jts1957
Veteran

Jul 22, 2009, 3:00 AM

Post #61 of 98 (1387 views)
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Re: [bogart219] Chassis number? [In reply to]	Can't Post

So where were we?

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Location: Far, Far Away

bogart219
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Jul 22, 2009, 10:41 AM

Post #62 of 98 (1381 views)
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Re: [jts1957] Chassis number? [In reply to]	Can't Post

I posted last night about 10:00 but now I don't see it on here. Strange. I'll post it again.

R3415 =3ohms
CR3417, CR3418 and CR3402 all = .5 one way, nothing the other way. (With one leg lifted)

IC3401 = resistance between pins 9 and 10 = 81.5 ohms.

Still working on those smd's
Do smd's resistors use a different color band chart than regular resistor?

bogart219
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Jul 22, 2009, 11:38 AM

Post #63 of 98 (1379 views)
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Re: [bogart219] Chassis number? [In reply to]	Can't Post

http://i526.photobucket.com/albums/cc344/bogey219/IMG_0007.jpg

Bottom 3 hole is qx3402

jts1957
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Jul 22, 2009, 7:50 PM

Post #64 of 98 (1375 views)
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Re: [bogart219] Chassis number? [In reply to]	Can't Post

Same resistor code.
Not home right now. Try same two IC pins with one pin floating. If stays under 100, add the IC to your list of bad parts. Angelic

Angelic

-------------------------
Location: Far, Far Away

bogart219
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Jul 22, 2009, 9:17 PM

Post #65 of 98 (1372 views)
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Re: [jts1957] Chassis number? [In reply to]	Can't Post

In Reply To

Same resistor code.
Not home right now. Try same two IC pins with one pin floating. If stays under 100, add the IC to your list of bad parts. Angelic

Angelic

Isolated pin 10 on IC3401 then measured resistance between pins 9 & 10. Still 81.5 ohms. Will add to list!

jts1957
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Jul 22, 2009, 9:20 PM

Post #66 of 98 (1371 views)
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Re: [bogart219] Chassis number? [In reply to]	Can't Post

Just out of curiosity: Pin 7 to Pin 9? Also 16 to 9?
R3415 = BAD.

Ron.M...

Quote

(Need to figure out how to get the white background out.)

Visine! (No, wait, that gets the red out!)

-------------------------
Location: Far, Far Away

(This post was edited by jts1957 on Jul 22, 2009, 9:37 PM)

bogart219
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Jul 23, 2009, 7:43 PM

Post #67 of 98 (1359 views)
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Re: [jts1957] Chassis number? [In reply to]	Can't Post

JTS, Took IC3401 off of board

9 to 10 = 81.4 ohms
7 to 9 = 3.1 mohms
16 to 9 = 86.9 Kohms

Later Smile

Smile

bogart219
User

Jul 23, 2009, 11:31 PM

Post #68 of 98 (1355 views)
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Re: [bogart219] Chassis number? [In reply to]	Can't Post

JTS, not sure on these smd's .No number markings. Does this photo help any?

http://i526.photobucket.com/albums/cc344/bogey219/IMG_0007-1.jpg

I measured these in circuit, was leary of unsoldering them. I will if I have to though!

jts1957
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Jul 24, 2009, 4:17 AM

Post #69 of 98 (1351 views)
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Re: [bogart219] Chassis number? [In reply to]	Can't Post

All is fine exept: QX (NOT IC) ".1" are "zero ohm jumpers"
You're sure BOTH 100 ohms (Brown-Black-Brown) are 98.? Earlier you said one was open - R3413M (the one that goes to QX3402).

Or did you...

Quote

Surface mounts on bottom side of board right? Numbers not on board. SMD that has one side going to G on QX3401 (R3418M)? is 98.7ohms. SMD closest to QX3402 (R3412M 1K?). Not sure on this one. It is solid brown color. There were four other ones throughout the board and they all check the same .1 ohm. The other smd's has resistor bands.

-------------------------
Location: Far, Far Away

(This post was edited by jts1957 on Jul 24, 2009, 4:21 AM)

bogart219
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Jul 24, 2009, 1:22 PM

Post #70 of 98 (1345 views)
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Re: [jts1957] Chassis number? [In reply to]	Can't Post

JTS, Yes both brown black brown smd resistors as shown in the picture are 98.6 ohms.

" QX (NOT IC) ".1" are "zero ohm jumpers" Not sure what you mean here. Are you saying those solid brown band smd's are zero ohm jumpers?

Are the two 98.6 ohm resistors in the picture R3412M and
R3418M that you referred to earlier? later

jts1957
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Jul 24, 2009, 7:40 PM

Post #71 of 98 (1341 views)
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Re: [bogart219] Chassis number? [In reply to]	Can't Post

Picture show IC401/IC402 - Should be QX3401/QX3402.
Yes .1 solid brown = zero ohm jumpers (wire).
And Yes on two resistors which now makes me wonder about IC. But IC gate drive resistance differs greatly one to the other, so I'd still say it's bad.

-------------------------
Location: Far, Far Away

bogart219
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Jul 24, 2009, 8:42 PM

Post #72 of 98 (1338 views)
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Re: [jts1957] Chassis number? [In reply to]	Can't Post

JTS, Whats the next step? Order some parts? Want me to check anything else? Smile

Smile

jts1957
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Jul 24, 2009, 11:56 PM

Post #73 of 98 (1337 views)
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Re: [bogart219] Chassis number? [In reply to]	Can't Post

Not at home at moment (where schematic is), so working off what we've already said:
AC Fuse obviously.
QX3402 = Definitely BAD (Shorted). (121-1189-01)
R3415 = Definitely BAD (open).(.15 ohm 3 - 5 watts)
IC3401 = up to you. Only 100 ohms away from QX3402. Check into. If cheap and available, probably best to change.
If you follow the path of destruction: ground through R3415, then through QX3402, through a primary winding of transformer, bridge rectifier and to the blown fuse. Bridge you say checked O.K., transformer winding WILL check O.K., other diodes and resistors in same vicinity checked O.K.
Think that's all. I'll double check later. Wink

Wink

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Location: Far, Far Away

bogart219
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Jul 25, 2009, 12:18 AM

Post #74 of 98 (1334 views)
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Re: [jts1957] Chassis number? [In reply to]	Can't Post

Hi JTS, Not exactly sure what you mean about that IC being only 1oo ohms from QX402. Could you explain please?

Doing a preliminary search on that transistor and IC, it seems I can get them for about $8 a piece. I'll put together a parts list and numbers and see if you concur!
Once more,thank you for your time!

jts1957
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Jul 25, 2009, 5:16 AM

Post #75 of 98 (1327 views)
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Re: [bogart219] Chassis number? [In reply to]	Can't Post

Pin #7 of IC3401 (221-749) goes to one side of R3418M (100 ohm). The other side of R3418M goes to the gate of QX3401 (121-1189-01). Pin #7 is 100 ohms away from the gate of QX3401. "JTS, Took IC3401 off of board 9 to 10 = 81.4 ohms | 7 to 9 = 3.1 mohms | 16 to 9 = 86.9 Kohms"
When IC3401 is mounted to the board, Pin #8 is tied to Pin #9 via a foil which is HOT ground. Remeasure Pin #7 to Pin #8 and see if still ~3.1mohms.

Pin #10 of IC3401 (221-749) goes to one side of R3413M (100 ohm). The other side of R3413M goes to the gate of QX3402 (121-1190). Pin #10 is 100 ohms away from the gate of QX3402. You claim "IC3401 = resistance between pins 9 and 10 = 81.5 ohms." Stayed same in or out of circuit - you were measuring the same two pins.

Now I know the two FETs are NOT the same "exact" part number. We know IC3401 is a "current mode controller" IC. Pin #7 drives the gate of one FET and Pin #10 drives the gate of the other. Presuming the drives are supposed to be similar, those resistance readings being so drastically different is suspicious.

Don't forget R3415.

-------------------------
Location: Far, Far Away

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