Will not turn on. Solid green led when plugged in otherwise no power. DM board repair not applicable, no DM board in this model. No capacitors look bad visually but have not had chance to check with cap checker. Does have 5 volt standby and the 10 volt standby line shows as 20 volts. I do have the schematic but thought somebody here might have a quick solution. Thanks
Look for swollen capacitors in the sweep power supply as well as in the main power supply. Make sure the main regulator is regulating at the proper voltage. A lot of times in these TV sets, the slight over voltage can cause the set to go into an x-ray protect mode, therefore confusing the real problem. Capacitors are very very common in the set to go bad. Good Luck
Did you get the service manual for this TV set yet? If you did, send me a copy please to [email protected]
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This model is equipped with a keyboard lock feature; this can be mistaken as a no power condition. To unlock the keyboard press and hold the "menu" button on the front panel for 10 seconds. 2. (Power LED may be on after plug in) check for no less than 4.4 volts DC at pin 3 of PC9A21 on the Power PCB, if low or missing replace PC9A21 part # 268P058020. Hope this helps if not let me know and I will go further
Sounds like you are on your way to fixing this set! Ok now you can check:Shutdown at power with self diagnosis error 2-2. Check for open fuses F9A04 and F9A05 part # 283P144080 on the +24 and -24 volt lines. If the fuses are open the convergence output circuit would be suspect. 2. Shutdown at power with self diagnosis error 2-1. At power on check for 12-volts DC at connector KH pin 8, if missing check IC9C51 part # 270P990010 and L9C52 part # 441D009020 on the Signal PCB.
You are correct! part # 283P144080 Yes and the convergence amps are probably the culprits. Remember also resistors in same area(replace)
Replace both to be safe, make sure you get good parts also I would go back with same maker. Also remember return resistors also in same area.
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I didn't have any voltage on pin 3 so I replaced the part. Didn't fix. Pin 1 has 20.7v, pin2 has 19.8v, pin 3 .9v, and pin 4 has 5v.
I traced back from pin 2 of pc9a21 and found q9a55 and d9a28 shorted. Replaced both and checked d9a29 zenier diode but did not replace.
4.7 volts restored to pin 3 of pc9a21.
Now power supply starts up and then shuts down after about 2 seconds. Error code flashes 22 for short circuit. What should I look for now.
Also wanted to say how much I appreciate your help.
I checked both fuses and f9a05 5amp is open.
Looking at the schematics the -24v line goes to the STK394-250 chips. Are those the convergence chips?
How can I tell which amp to replace? Or should I just replace both.
I checked all the resistors and none look smoked and using my meter they all check ok. Should I go ahead and replace them anyway? Thats a ton of 2 and 3 watt resistors.
Also should I replace D9A61 and C9A74? They set in parallel behind the fuse that blew. I was thinking that although they test ok they might have been stressed by the current before the fuse blew. Does the convergence amps going out ever take the two coils out that feed the -24v.
Thanks
I had another question. When I shine a flashlight down into the picture tubes I notice that there appears to be debris laying on the bottom of the lens. Should there be anything floating inside the coolant liquid. Can the liquid be easily replaced? If it can will the seal have to be replaced or reused? I can order the fluid from mcm electronics. If I can do this how much realignment to the tubes will be required.
Thanks
Hey troylove11,
I accidentally hit accept button on this page but tv is still broken. So I have to try and get in touch with you this way.
I replaced the convergence chips and the resistors and then found a bad cap in the -27v line right behind the rectifier diode. Replaced diode and now -27v back but it now shuts down with a 21 error. I know this is an x-ray error but what are your thoughts on what to look at next.
Thanks
I replaced the regulator and that didn't fix it. I also basically replaced all the caps in the power supply. Except the big filter caps.
What should I look at next?
I now get an xray protection error. I replaced all the power supply caps just in case and I replaced the voltage regulator. Still the xray error. Any thoughts on what to look for next.
If the HV doesn't come up will that give a false xray protection error?
I was trying to figure out why the HV regulator ic (mspad401) was not putting any voltage to the HOT. I traced back from pin 3(HD IN) and found that pulses were indeed coming from the deflection circuit. But they were stopping before a resistor tied to the collector side of a transistor that acts like a switch when the tv is first turned on. I checked the voltages around this transistor and checked the transistor and found no problems. I then removed the mspad401 ic and re-checked voltages and signal and the pulses have returned. So does this mean the hv driver ic is bad? Or have I missed something.
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