Old school Fortune Magic Green 14" S/N 96097669 CRT

[jts1957]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

Does set fire up if 12V is connected momentarily to pin #20 of TDA9102?

[senz_90]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

this is the schema on pdf, not complete.. I am sorry.. I am too busy to draw all surrounding components, but I am checks B649A and C1815 transistor good.

and some picture, I have try to makes a good picture and hope you can see it..

D2 is zener diode = ZD001 on board mark
D1 = D002 on board mark
R1 = R005
R2 = R001

any ideas?

[senz_90]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

'OUT' as in LM358 Pin #1 (Out1) or Pin #7 (Out2)? What's on LM358 pin #8?

I means Out is OUT that marked on the board, not Out from this dual Op Amp.

I'll draw this LM358 schematic soon.. please help me and keep update if you don't mind.
I have to take a time to install my schematic drawing software, it has a long time since I was make a PCB so my brother uninstall it.

[jts1957]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

'OUT' as in LM358 Pin #1 (Out1) or Pin #7 (Out2)? What's on LM358 pin #8?

[senz_90]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

Unless or until you get approximately 12-18 volts on pin 20 of TDA9102 you won't be getting any high voltage period.

Are there any identifying numbers on main board that might indicate a model number or chassis? Model would likely contain a '14' in it.

The question in my head is nothing voltage to Vcc TDA9102 that connected from OUT mark on board LM358 circuit, but surrounding components were checked good, probably I miss something.
I can't see any number model for this monitor on his case.

but this main board has a code
PBS-31-1440
Li Lung C 04-0

maybe this could give you any ideas? I have checked this number on googling, unfortunately I get nothing..
thank you for reply

[jts1957]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

Unless or until you get approximately 12-18 volts on pin 20 of TDA9102 you won't be getting any high voltage period.

Are there any identifying numbers on main board that might indicate a model number or chassis? Model would likely contain a '14' in it.

[senz_90]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

that pen may do the trick.
i still have one i made from a plastic drink stirrer and neon glow lamp.
the fully insulated handle is so you dont get bit if your fly or lopt has bad insulation and you draw an arc with it.

yeah, i will test it. for now, i am just get the board out and try figuring what is the culprit, this is wasting time but there is another way I think except checks one by one. i got no clue why TDA 9102 chip didn't get Vcc where is connected to OUT marked from LM358 Op Amp circuit. The diodes and resistor surrounding this chip was checked fine, i'll try check transistor later.. Maybe this chip itself were defective.

I have question, NE555 chip right here is act as oscillator? anyone ever looks circuit use this chip before? it didn't have Vcc.

[kc8adu]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

that pen may do the trick.
i still have one i made from a plastic drink stirrer and neon glow lamp.
the fully insulated handle is so you dont get bit if your fly or lopt has bad insulation and you draw an arc with it.

[senz_90]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

NO actual physical connection. A quarter inch away should do (The closer to flyback the brighter it will light - IF AC high voltage is present. Many electrical supply stores sell these to test for AC at electrical outlet pins. Just separate the metal pins and insulate them with electrical tape

I have never see this bulb before..
On my town, when we want to test AC mains electrical socket HOT line use this tester pen.
this could be use to connects it to anode cup to make sure it has a high voltage AC? I don't know this anode cup has a DC or AC, sorry for my ignorance..
feel nothing when placing my back of hand on the faces of screen.

btw, I have test to measure the IC Vcc pin yesterday and just get the voltage on
TDA 1872 = 18V
LM358 = 12V
CA3080 = 0
NE555 = 0
TDA 9102 = 0
WT 8043 = 0

and I am notice that trace before LM358 has a symbol I don't know what it means exactly. it has symbol = V, H, IN, OUT
and i get the 12V voltage at IN trace directly from secondary PSU connected to Vcc LM358, but i measure the OUT trace and get no voltage.
I am also measure 7812 voltage regulator at secondary PSU and get a 12V exactly.
it looks like I will makes you confuse and my problem didn't as simple as i thought, huh? any idea or advice? thank you for your reply.

[jts1957]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

ok, because of language barrier, i didn't understand clear how to connect the bulb. would u give me a rough schematic? and what pins of flyback winding to connect with bulb?

NO actual physical connection. A quarter inch away should do (The closer to flyback the brighter it will light - IF AC high voltage is present. Many electrical supply stores sell these to test for AC at electrical outlet pins. Just separate the metal pins and insulate them with electrical tape

[senz_90]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

Hold by means of insulated leads a bare bulb NEON lamp near flyback winding and see if it glows. That will safely tell if set has (AC) High Voltage or not. Hairs standing up on back of your hand/arm placed near the face of CRT as set is first turned on will tell if the set has (DC) High voltage.

ok, because of language barrier, i didn't understand clear how to connect the bulb. would u give me a rough schematic? and what pins of flyback winding to connect with bulb?

about back hand placed, I will test it..

Just asking, did you plug in a signal source when testing? These monitors will not power on unless there is a signal input to them, and will stay off with power light on. The 820n capacitor needs to be exact value, as it sets a flyback value. The neon lamp trick will tell you if it is running with a signal input. Resolder the LOPT pins and the line output transistor, along with the connections along the base and the line driver side along with the low value resistors connected there. With the new chopper chip did you change the 100uF 25V capacitor that provides the supply to the chip, it will likely be close to dead now.

yes, I am plug this monitor vga cable to my CPU and nothing happened. It looks hard to find this caps on my town, but i'll try.
where pins of LOPT pins and where pins of H.O.T to connects bulb? Collector or Base? Emitter is common ground as i see.. where is line driver side? I have see a low value resistor 0,33 ohm 2W near the heatsink. 100uF caps on secondary?
sorry for this dumb question, it's hard to understand for me because im really new to this TV and have a bad english..

thank you for your help

[SeanB]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

Just asking, did you plug in a signal source when testing? These monitors will not power on unless there is a signal input to them, and will stay off with power light on. The 820n capacitor needs to be exact value, as it sets a flyback value. The neon lamp trick will tell you if it is running with a signal input. Resolder the LOPT pins and the line output transistor, along with the connections along the base and the line driver side along with the low value resistors connected there. With the new chopper chip did you change the 100uF 25V capacitor that provides the supply to the chip, it will likely be close to dead now.

[RJARRRPCGP]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

1996 is not that old for a CRT, although it would certainly benefit from recapping.

QFT. I have a 1997 Gold Star Studio Works CRT that was given to me not that long ago and it works nicely, just not perfect screen alignment, at least with the pincushion and triangular alignments. I dunno why. Tube still looks healthy.

While OTOH, I expect tons of LCD monitors to be trashed in 2022, because of bad caps or inverters on CCFL-lit LCDs.

[jts1957]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

Hold by means of insulated leads a bare bulb NEON lamp near flyback winding and see if it glows. That will safely tell if set has (AC) High Voltage or not. Hairs standing up on back of your hand/arm placed near the face of CRT as set is first turned on will tell if the set has (DC) High voltage.

[senz_90]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

But the issue is not just a badcaps

I don't know exactly old or not, but it has been a long time stay in my warehouse.

[Heihachi_73]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

1996 is not that old for a CRT, although it would certainly benefit from recapping.

[senz_90]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

For note. I have see the filament is glowing into orange colour. so this is mean my filament on CRT neck glasses is fine, right? about high voltage on anode cup, I don't have HV probe to make sure. And we know that B+ is ~100VDC so the PSU section is okay right now?
I don't know exactly where is horizontal deflection circuit to troubleshoot because many site mention about that, maybe this will give you a sign about the circuits, it has TO220 package:
FQP6N60A (Primary FET PSU)
IRF630 (Fet B+)? didn't sure enough
TIP 127 (doesn't know this is for where section)
C5149 (HOT)
B649A (doesn't know this is for where section)

for the IC
KA3842BN
NE555 Timer
Weltrend WT8043 N201
TDA 9102C/T
TDA 8172
LM358 Op Amp
CA 3080

I have already download all datasheet. I'll upload here soon.
Btw how to find ABL, G1, G2, etc pins on the flyback? for Collector, B+, GND i know.
if you have something wanna to test, just ask me

thank you for your time

[senz_90]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

Yes. With the monitor switched ON of course. Test voltage output of those diodes. There could be negative rails depending on the design. The voltages are usually marked somewhere on the silkscreen on most monitors, can't see the pictures clearly so i don't know about yours.

thank you for reply, well, i got this result friend as i upload the picture, I know this is dumb action, I am just measure all of pins and this is the result(maybe damage my meter, fortunately nothing was happened), some pins just connected to resistor so i think the no voltage pins have a trouble?:

pin 1 connected to C431, D409 and IRF630 = 100VDC
pin 2 Collector H.O.T= 100VDC
pin 3 connected to D605, tip127 = 100VDC
pin 4 B+, D604 = 100VDC
pin 5 (anode side) so it seems like no problem? = no voltage
pin 6 connected to VR Brightness (cathode side) = no voltage
pin 7 connected to R604 = no voltage
pin 8 = GND
pin 9 connected to R602, C601 = no voltage
pin 10 connected to R601, C453, R436 = no voltage

how do you think? I am just googling and that is many site mention about horizontal side when we have no picture symptom. any advice ?
I don't see any voltage marked on silkscreen. but i'll checks it again. sorry for blurry picture, but i don't have a good camera. just android camera or handphone camera.

[Th3_uN1Qu3]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

Ok. so I have to checks this diodes like to checks secondary PSU diodes on their cathode? is there any negative rails there?
I am really newbie on TV or LCD, so please don't feel bother with my dumb question.

Yes. With the monitor switched ON of course. Test voltage output of those diodes. There could be negative rails depending on the design. The voltages are usually marked somewhere on the silkscreen on most monitors, can't see the pictures clearly so i don't know about yours.

[senz_90]

Re: Old school Fortune Magic Green 14" S/N 96097669 CRT

thank you, this wouldn't happen without your help. YES. HOT were checked fine, because I am measure it off circuit to make sure and it has a little different because a damper diode insidely..

Ok. so I have to checks this diodes like to checks secondary PSU diodes on their cathode? is there any negative rails there?
I am really newbie on TV or LCD, so please don't feel bother with my dumb question.

so I am understand a bit about rebadged. i'll inform you with progress. thank you !!