Re: LG 42PA4500 Suspected bad main board (double check my logic)
Just confirming here. I don't do many PDP sets at all.
hardwareguy
Badcaps Veteran
Last Activity: 10-26-2016, 01:08 PM
Joined: 06-15-2006
Location: Dallas Texas
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Re: Should I power this thing up?(I HAVE NO VARIAC)
While I will say prices have gone INSANE with these, the particular unit you have seems to need a tuner alignment very badly. The tuners in these are quite sensitive if they're operating properly.
I'd also recap that voltage regulator board and adjust its output. The tuner won't work for crap if it's out of whack....Leave a comment:
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Re: Fosgate Prime R500-1 car amp
Most car amps detect DC offset via the PSU rails.
The theory being that if a rail gets dumped into a speaker, one rail will go low while the other will remain high. If this differential occurs, the PWM controller shuts down.
I still prefer cutting the speaker outputs and I would test for offset every time you fix any direct coupled amp. Much over 15mV with the gain at minimum and I start asking questions, 50mV or more and I start changing parts. (What I change/test and in what order depends on the severity of the offset....Leave a comment:
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LG 42PA4500 Suspected bad main board (double check my logic)
I just want a sanity check here...
Got this TV that has funny noises from the Y sustain board, no picture and no sound. Other than a dimly lit black background, it's dead. I don't even get a standby light. The optical audio terminal doesn't have a red light either, which I find odd.
Vs and Va are happy and I have 5.2 and 17V to the mainboard as well.
If I short the test pattern pads on the panel LVDS interface board and plug the set in, I get some pretty test patterns. Funny noises from Y sustain cease when the patterns are playing, it gives only a very faint... -
Re: Dell Inspiron One 2020 Motherboard Build
Get video from the LCD connector. Find out what kind of LCD it had and that will lead you to the interface and very likely, the pinout.Leave a comment:
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Re: Daytek 42DKf3 Volume at 100%
Check for bad caps but it's probably a bad mainboard. See if there is a reset procedure before replacing it though.Last edited by hardwareguy; 11-24-2014, 06:43 PM.Leave a comment:
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Re: Samsung PN60E530A3F...makes startup noise, LED blinks 6 times and then dead.
It appears to be the Vscan rail buffer. Do you have a schematic for this TV?...Leave a comment:
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Re: Samsung PN60E530A3F...makes startup noise, LED blinks 6 times and then dead.
If that shorted then it could have taken out the controller but it's *in theory* protected against such.
The small SMD diodes on the solder side are looking good as well.
I'll probe that IC after I fix a friend's car.Leave a comment:
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Re: Samsung PN60E530A3F...makes startup noise, LED blinks 6 times and then dead.
No short between source and drain on the SMPS IC, will test for output waveform, controller Vcc and main supply. No other open fusible resistors found.Leave a comment:
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Re: Samsung PN60E530A3F...makes startup noise, LED blinks 6 times and then dead.
Integrated SMPS and switching MOSFET. I'll dig up the datasheet and see if I can figure things out....Leave a comment:
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Re: Samsung PN60E530A3F...makes startup noise, LED blinks 6 times and then dead.
I have found an open resistor on the Y main board. R5027 is open, 100k and it appears to be a 1/2W fusible resistor. This resistor is in parallel with C5091, the cap that had visible bulging.
Check U5014?Leave a comment:
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Re: Samsung PN60E530A3F...makes startup noise, LED blinks 6 times and then dead.
No appreciable change in voltages were found after this test....Leave a comment:
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Re: Samsung PN60E530A3F...makes startup noise, LED blinks 6 times and then dead.
Ysch: 0V
Vscan 15V: 800mV
Intuition tells me to hunt for a short.Leave a comment:
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Re: Samsung PN60E530A3F...makes startup noise, LED blinks 6 times and then dead.
I will be available for more tests Friday night. (may be early morning for you, I'm -6 GMT)
I'm off to my home town for lucrative Apple repairs and to help repair the upstairs bathroom. (It got torn apart by plumbers replacing 80 year old pipes.)Leave a comment:
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Re: Teapo made power supplies?!
Indeed and they were good quality. I used to have an old full AT 200W unit...it was a beast inside!Leave a comment:
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Re: Samsung PN60E530A3F...makes startup noise, LED blinks 6 times and then dead.
With the lower ribbon cable from control to Y sustain disconnected I have a 1Hz blink and perfect Vs and Va rails.
With the lower ribbon cable attached: Vs and Va are shut down, light stays on for approximately 5 seconds and stays off for approximately 2 seconds.
The cap that failed on Y sustain has a very slight bulge at the top. It did not leak.Leave a comment:
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Samsung PN60E530A3F...makes startup noise, LED blinks 6 times and then dead.
So this thing, for which I have no service literature whatsoever for just showed up at the door to be looked at.
This customer is a bit of a DIYer so he gave me the Y sustain board to recap. A 250V 150uF cap (C5091) was bulging and all of those types (Samwha PF) were replaced with Panasonic EE high ripple type caps. When that failed to fix the issue, I told him to bring the entire TV in as there was no way I was going to troubleshoot this one board at a time.
The symptom is the same: The boot sound plays, there is no image and then the standby LED blinks 6 times.... -
Re: Colby 32" TFTV3229 Power failure
Caution! This TV has a recall for a fire hazard.
From the US CPSC: "This recall involves black Coby 32-inch flat screen televisions with model number TFTV3229 and serial numbers beginning with LG and that have M07 or M10 in the 9th, 10th and 11th position of the serial number."
So if you chose not to scrap it and it has that serial number range, use extra scrutiny and look for components that appear to have run hot. You may have to do some minor reverse engineering to find out why it overheats, the...Leave a comment:
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Re: Protek 6300 "5 in 1" DMM
I will have to *find* it first! It's in the garage / Storage Facility of Doom (a subsidiary of The Mad Scientist's Lair). Wish me luck....Leave a comment:
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Re: Protek 6300 "5 in 1" DMM
Long term test update!
My meter has died due to corroded batteries...I'm not faulting it for it's demise. That's clearly all on Duracell and I.
With that said, I have some gripes. The humidity function is *hilariously* slow. You want an even semi accurate reading? Leave it on for an hour and you might get within 10%!
The internal temperature is almost as slow and noticeably inaccurate. The thermocouple is good though.
I have no standard for which to test the light meter but it reasonably...Last edited by hardwareguy; 09-22-2013, 01:36 AM.Leave a comment:
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