I have a Hitachi 27GX01B bought it new in 2002, I now have all the telltale symptoms of a bad Pump up cap, I can provide schematics, if some body can point out the offending caps number {c????} I am fully aware of the 50Kv in there, and the danger involved, and know what im doing, just not too sure which cap it is. I have the PDF schematics, or they can be downloaded here, "Its in 3 parts" not sure why. http://www.eserviceinfo.com/download.php?fileid=11779
Please could i get a little help, im really getting sick of these lines at the top of my screen, theres a complete circiut diagram that you can download or give me your e-mail and i could send it to you all I need to know is which cap in the vertical output circuit is known as the pump up capacitor, if you could tell me the number i.e. c401 thats the first one in the V/O circuit. Please I would really like to get this tv working, I find my eyes drawn to the lines and rollover effect, and its very annoying. Thank You in advance, c'mon guys somebody must know the answer :PPlease could i get a little help, im really getting sick of these lines at the top of my screen, theres a complete circiut diagram that you can download or give me your e-mail and i could send it to you all I need to know is which cap in the vertical output circuit is known as the pump up capacitor, if you could tell me the number i.e. c401 thats the first one in the V/O circuit. Please I would really like to get this tv working, I find my eyes drawn to the lines and rollover effect, and its very annoying. Thank You in advance, c'mon guys somebody must know the answer :P
If your not gonna help please just say so, so I can move on to another forum to seek assistance."sigh"
If your not gonna help please just say so, so I can move on to another forum to seek assistance.
heres a pic.... maybe you dont belive me, orr.....whatever anyway here it is.heres a pic.... maybe you dont belive me, orr.....whatever anyway here it is.
http://www.fixya.com/support/t266710-hit... check here, I posted the problem 3 times, to be sure to get a quick response, if you check the link above you will see that I got some help, but i also had the service manual.
this may or may not help, it should be on the hot side of the board "be careful" and will be near a cluster of wires that go to the back of the picture tube, there is usually a small heatsink near the wires, there are a few small radial electrolytic caps in that area, I changed c454 which was right up against the heatsink, so was the most likely culprit, it had the values " 10mm 220uf 35v" so i went to "the source/radio shack" and picked up some cheap "12mm 220uf 50v" caps and used that to replace it, "you can use a higher voltage rated capacitor, in place of a lower V cap, BUT NOT THE OTHER WAY AROUND, been working flawlessly for a few months now, hope you find the problem, I will take a quick look see if i can find the service manual for your tv, if so i will post here.
L8r, Reeves Good Luck, and watch out for the flyback tranformer it can kill.http://www.fixya.com/support/t266710-hitachi_27gx01b check here, I posted the problem 3 times, to be sure to get a quick response, if you check the link above you will see that I got some help, but i also had the service manual.
this may or may not help, it should be on the hot side of the board "be careful" and will be near a cluster of wires that go to the back of the picture tube, there is usually a small heatsink near the wires, there are a few small radial electrolytic caps in that area, I changed c454 which was right up against the heatsink, so was the most likely culprit, it had the values " 10mm 220uf 35v" so i went to "the source/radio shack" and picked up some cheap "12mm 220uf 50v" caps and used that to replace it, "you can use a higher voltage rated capacitor, in place of a lower V cap, BUT NOT THE OTHER WAY AROUND, been working flawlessly for a few months now, hope you find the problem, I will take a quick look see if i can find the service manual for your tv, if so i will post here.
L8r, Reeves Good Luck, and watch out for the flyback tranformer it can kill.
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I have the same problem with a Phillips Model: 32PT5441/37
ISo far all I can find on this TV is the pump-up capacitor for the vertical output circuit may be bad but I can't find very much information on this model.
I do high end PC system builds and PC repair but have no expertise in TV repair so any help or a solution to my problem would be appreciated...
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Sir the problem of your unit is the vertical section of your tv, first try to tap the side of your tv if the tv reacts there is a cold solder in the vertical section specially in the IC if you remove the cover of your unit, but be sure to unplug it first try to observe the solder part of the pcb look for this cold solder or loosed solder.
look for this sign. To fix this you should resolder it using soldering iron, soldering lead, desoldering pump.
And also bulging capacitor is the cause of this fault try to look for this capacitor, this bad capacitor is producing a low and unfiltered dc output that causes your unit to malfunction, replace this bad capacitor with the same type and observe polarity.
This is the bulging capacitor, hope this help good day and best regards.
Hi:
You need to have the solder connections on the vertical output IC. Also there is pump up capacitor that goes bad or leaky that need to be checked. Rework the entire vertical section of the set to make sure all solder connections are ok.
You have a vertical output IC that needs repaired. You may need to only resolder the vertical output IC. If then you do resolder, you will need to check and replace any capacitor in the immediate area of the vertical IC. A weak or bad capacitor will heat up the IC, and create rings on the pins under the IC. Also check the solder grounds on any resistor and diode that are immediately near this IC. This will bring your TV back to full view. Thanks for asking and show a few hands of support!
hello, This is a vertical deflection problem - possibly a bad capacitor, bad connection, flyback/pumpup diode, or other component. None of these should be very expensive (in a relative sort of way).
If the symptoms change - particularly if they become less severe - as the set warms up, a dried up electrolytic capacitor is most likely. If they get worse, it could be a bad semiconductor. Freeze spray or a heat gun may be useful in identifying the defective component.
It is often easiest to substitute a good capacitor for each electrolytic in the vertical output circuit. Look for bad connections (particularly to the deflection ports), then consider replacing the vertical output IC or transistor(s).
A missing power supply voltage, defective vertical output IC, or a component associated with it is likely bad. A bad connection or blown fusable resistor may be the cause of a missing power supply voltage.
The following are NOT possible: CRT, flyback (except possibly where it's the source for a missing voltage but this is more likely just a bad solder connection at a flyback pin), tuner where the controller is at fault - see the sections on these specific brands. I am just trying to think of really expensive parts that cannot possibly be at fault. Hope this will help..
Hello,
This require you opening the television and having an ohmmeter to work with.
This is a vertical deflection problem - possibly a bad capacitor, bad connection, flyback/pumpup diode, or other component.
If the symptoms change - particularly if they become less severe - as the set warms up, a dried up electrolytic capacitor is most likely. If they get worse, it could be a bad semiconductor. Freeze spray or a heat gun may be useful in identifying the defective component.
It is often easiest to substitute a good capacitor for each electrolytic in the vertical output circuit. Look for bad connections (particularly to the deflection yoke), then consider replacing the vertical output IC or transistor(s).
A defective deflection yoke is also possible or in rare cases, a bad yoke damping resistor (e.g., 500 ohms, may be mounted on the yoke assembly itself).
Where there is a wide running vertically on the screen the likely causes could be a missing power supply voltage, defective vertical output IC, or a component associated with it is likely bad. A bad connection or blown fusable resistor may be the cause of a missing power supply voltage.
The following are NOT possible: CRT, flyback (except possibly where it's the source for a missing voltage but this is more likely just a bad solder connection at a flyback pin), tuner (except for the famous RCA/GE/Proscan or Sony models where the controller is at fault - see the sections on these specific brands). I am just trying to think of really expensive parts that cannot possibly be at fault :-).
Note that some movies or laser karaoke discs are recorded in 'letterbox' format which at first glance looks like a squashed vertical problem. However, the picture aspect ratio will be correct and turning up the brightness will reveal a perfectly normal raster above and below the picture.
Have you vertical deflection circuit checked for bad Vertical IC, and or Bad vertical Capacitors in the vert output section for the deflection board. Also have Vertical output Pump up Capacitor replaced, also have B+ voltage check coming from flyback transformer, for any open fusible resistors
The faint white lines at the top of the screen is the warning that the pump-up capacitor in the vertical output circuit is going bad and the output itself is about to short out. When the TV stops working, the vertical output IC has finally shorted out. Replacing the vertical output IC, the pump-up capacitor and possibly a small value resistor next to the flyback (B+ for the v-out) should bring the set back to life.
Check c458; (100/16) c454; (220/35) c453; (470/35); c451 (2.2/50) all are electrolytic capacitors located near IC 451 (la7845) If you have an ESR meter it would help out greatly to identify the weak cap or caps.
When you see white lines at the top of the screen, it means that the pump-up capacitor next to the vertical output IC is bad and the IC is about to quit. When the output finally quits, you get a black screen with possible dim spots. The vertical output IC and its pump-up cap will have to be replaced, and the little fuse resistors next to the flyback in the + and - supplies to the vertical output IC must be checked too. If you have experience working on TV's then you can do it yourself, but if not then have the set serviced by a tech experienced in Sony sets.
If you have a picture but the top is folded over, your vertical IC is probably good and you need to replace the pump-up capacitor next to the IC. When the pump-up cap (typically a 47 or 100uF 35V cap) is open then the picture will have white lines and foldover at the top. The typical vertical output IC is the LA7838, but I am not familiar with exactly which output IC your set uses.
Please could i get a little help, im really getting sick of these lines at the top of my screen, theres a complete circiut diagram that you can download or give me your e-mail and i could send it to you all I need to know is which cap in the vertical output circuit is known as the pump up capacitor, if you could tell me the number i.e. c401 thats the first one in the V/O circuit. Please I would really like to get this tv working, I find my eyes drawn to the lines and rollover effect, and its very annoying. Thank You in advance, c'mon guys somebody must know the answer :P
"sigh"
If your not gonna help please just say so, so I can move on to another forum to seek assistance.
heres a pic.... maybe you dont belive me, orr.....whatever anyway here it is.
reeves, did you find the solution?
Phillips Model: 32PT5441/37 32" TV
http://www.fixya.com/support/t266710-hit... check here, I posted the problem 3 times, to be sure to get a quick response, if you check the link above you will see that I got some help, but i also had the service manual.
this may or may not help, it should be on the hot side of the board "be careful" and will be near a cluster of wires that go to the back of the picture tube, there is usually a small heatsink near the wires, there are a few small radial electrolytic caps in that area, I changed c454 which was right up against the heatsink, so was the most likely culprit, it had the values " 10mm 220uf 35v" so i went to "the source/radio shack" and picked up some cheap "12mm 220uf 50v" caps and used that to replace it, "you can use a higher voltage rated capacitor, in place of a lower V cap, BUT NOT THE OTHER WAY AROUND, been working flawlessly for a few months now, hope you find the problem, I will take a quick look see if i can find the service manual for your tv, if so i will post here.
L8r, Reeves Good Luck, and watch out for the flyback tranformer it can kill.
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