Re: LG 50PK790 No Image No Sound
You are trash!
i try to talk simple all this gas inside a plasma is acting like a Phosphore.
In the instustry is a common language from the past every technician know this.
I do this for a living if you guys thinks you smart i said all the common problems on lg plasma in the above post.
charis
Senior Member
Last Activity: 05-14-2016, 02:04 PM
Joined: 03-24-2016
Location: athens
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Re: LG 50PK790 No Image No Sound
if you have sound and not image is the Y SUS the IGBT dont have corect voltage and flex cables dont make good contact.If no sound also the main problem.
If your picture is corrupt or washed colors change the caps on Y & Z sustain boards calibrate the voltages VA VS.
If start and shutdown after 10 minutes or more is your power supply.
For the other set they start putting red or green dots and with time the problem get bigger but sometimes for example if you use a dvd input stop or if the unit get warm.
Its overload...Last edited by charis; 05-14-2016, 11:25 AM.Leave a comment:
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Re: Yamaha RX-396 powers off after 2secs
To make correct measurement put the zener out of circuit.
Now on zener you will see a black line in the one size.
Put your meter on resistance(diode tester or 2k scale) the com to the black side of zener the V/Ω το the other side.
You will see a resistance of 750Ω.
In reverse you must have infinity.
This is 15v zener.
Are you the first person on this unit did you see it working?
The 2 second is probably the time that the 2 main caps need to full charge.
Put out the...Last edited by charis; 05-11-2016, 04:21 AM.Leave a comment:
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Re: Yamaha RX-396 powers off after 2secs
I see on schematic that you have 2 relays on main2 (mains and on 12v output circuit )and one at main power who is part of the protection circuit(24v).
The protection circuit signaling direct to Mitsubishi processor with 5v.
The 12v from main2 gives the +5v from regulation circuit and also feed the tuner and reset fuction and then goes to micro with a pull dowh resistance of 100k to 5v.This voltage monitor from DTA114A who control the regulation circuit on main1.Also going to input 2.
The major problem in this units and...Leave a comment:
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Re: Pioneer Elite VSX-33TX Receiver - Standby Only
Your regulator ic its ok.Input 15 output 5.5v.
To make it simple one size of the relay its on mains voltage the other on the 15v and signaling the NJM78M56F when its close to sent the signal on TRANS 2-1 ASSY(AND BACK).That signal is going to the speaker relay and if present all the krc101 starts and close the relays on ouput terminals.All this is under stand by voltage.
So if you dont have stand by or the pulse of 5v on pin4 on CN3005 nothing works.Also your +15/-15v dont start because ST G goes to regulation board....Last edited by charis; 05-08-2016, 04:51 AM.Leave a comment:
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Re: Sansui 5000a blows right channel fuse
Hi.
This is well know problem on this units and also on BA3000,A-700,1000X,A1100 etc.
Alot of times the relay stuck dont work propertly also the driver transistors are bad.
They use slow 6,7 MHZ transistors and if you change it with a fast ones the sound changes very much losing the warm.
Very dificult to find the same ones.
Also sometimes the TOSHIBA output transistors are pair with another brand and that seems to give problems.
For sure you have to changes all caps and be carefull because you will...Leave a comment:
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Re: LG 50ps3000 power fault
Hi.Its well know problem.
If your set start even after 15 minutes the problem is mainboard bga chip.
Put the power supply out of the set and jump it to measure VA VS.
If you have voltage put it back then put you meter on the pin who sent the power signal to power (from logic)and see when you start the tv if you have 3,2v.
If not take the mainboard out check for cold joint and reflow the bga with hallogen lamp.
If your YSUS and ZSUS dont work you hear a ham and the set are completely dead ,the led on logic board dont...Leave a comment:
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Re: Pioneer Elite VSX-33TX Receiver - Standby Only
What relay?
The unit have 5 relays on SP/PS,1 on primary assy and a lot of transistor resistors who are very sensitive.
Be carefull this is a very sophisticated unit who monitors anything.
If you are not on the field please sent it to a proffesional.Leave a comment:
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Re: Vizio E37OVA hdmi ports no signals
From what i see in the photo they using one HDMI chip.All the big brands like lg or samsung have separate hdmi ic for each port.When the 5v due to short in cable or to input device blow an hdmi the others keep work.
In your set this dont happen.
Check FB 503-504-502-506 and the 2 resistors near.Also near CN506 you have a resistor with a zero on it.
On pin 18 in HDMI port(first down left as we look from the front) you must have 5v all times.Leave a comment:
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Re: lg 60ld550
Correct.
Jump 3.3V from
the VCC (is label on pcb) to
pin of CN1 who is ground.
Jump 12v from power to the t con fuse F1 .Last edited by charis; 04-26-2016, 09:13 AM.Leave a comment:
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Re: LG 47LN5200_U: PWR, MAIN, and all LEDs replaced, no picture
If your backlight start and the panel stay black is T con problem.
Usualy this symptoms happen to samsung tv but the sound works.
Try to heat the main processor and see if you have picture untill he cools .
Also check the regulators near processor specially the 5v and VCC.
If nothing happen your tcon is faulty.
To test Tcon jump 12v from SMPS to the Tcon fuse.Disconect the LVDS cables Jump VCC 3.3v to the LVDS(CN1) connector ground pin.Aply ac to power supply, patterns of White, Red, Blue,...Last edited by charis; 04-26-2016, 04:10 AM.Leave a comment:
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Re: lg 60ld550
If your led blinks and the tv dont start is inverter problem.See if you have start signal from main board.
Check if you have 3.2v on DRV_ON and also PWM-DIM1 tupical 1.2 -1.6v.
Also check my post about lg Start Up Sequence and Voltages.
[url]https://www.badcaps.net/forum/showthread.php?t=53414[/url]Re: lg 60ld550<br /> <br /> If you... my post aboutLeave a comment:
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Re: Samsung LNT4671FX LCD weird screen glitches
Horizontial lines on all screen more visible specially to the right is t-con board issue...Leave a comment:
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Re: Yamaha RX-V2700 Stereo sound okay Surround crackles
Its normal on analog inputs to have some noise on full volume.
Enable the pure direct and you will be fine.
Put the volume to full and with no signal you hear a noise if you put your ear to the tweeter.Its normal.
Also select a digital input and see if you have a ham probably not.
At the end make sure that your mains power socket have ground .Leave a comment:
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Re: Yamaha RX-V2700 Stereo sound okay Surround crackles
If you hear the relays click when the sound cut off on surround you have cold joints probable on the speaker terminals(some people is barbarians when put the cables) but also in the pcb from vibrations.Leave a comment:
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Re: Yamaha RX-V2700 Stereo sound okay Surround crackles
Hi.
This model amplifier have overheating problems.
The sympoms is that on +5 volume after couple hours cut off sound and after 15 minutes start sound again.Then after a short time cut out again.
The problem is bigger when you put speaker with low (89dB) sensitivity.
Your impendance selector must be at 8 Ω also the true watts is much lower that the manufacter said and have a lot of clip on big volumes.
So a lot of times the thermal protect goes on.
Now your problem seems to be...Leave a comment:
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Carver pm 1200
ok i have on the bench a CARVER PM 1200.
This unit was on use since the 1990 in a cafeteria.
Very good unit good sound simple with not much ic and fancy systems.
So when all ask me what to buy from second hand or from ebay i suggest to by this mid 90s
amplifiers because is very simple on troubleshooting and fix.
So the main problem was that one channel no sound.
All the transistor are ok.
The power supply are all there(+/- 124,+/-76,+/-36,+/-11,).
Why so much voltages?Because use a magnetic field power supply and depend on a simple triac...Last edited by charis; 04-19-2016, 06:58 AM. -
Re: TV keeps blowing fuses !
Put out the brige rectifier.
Now with a multimeter put the com to + and V/Ω to -.
You see a resistance of 1.5KΩ.
Now put the com to + and VΩ to one of ac input.Do this again with the other ac input.
You see a resistance of 650 Ω.
If you put the V/Ω to + and the com to - or to ac you have infinity.Last edited by charis; 04-15-2016, 04:07 AM.Leave a comment:
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Re: Yamaha RX-A720
Ok.
First start by cleaning the switches and the volume control.
After that check all the ribbon cables to have good contact.
Then check if the output to speaker terminals is steady if not resolder them and cleaned.
Try a spare cable to speakers.
Make a visual inspection and take photos.See if you smell something or you have discoloration at any part and pcb.
Now try all the channels if have output(and the surrounds).
Next step check if you have good sound on headphones jack.
Reset the unit or go to previous...Leave a comment:
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Re: Yamaha RX-A720
Look i fix an RX-V1500 the problem was dc on output.When you push the speaker A-B was putting a noise and the volume goes down.
the problem was the 5,2v on C586 C587 the R644 D503,D504,D505 and on R650 on pin 139 of the CPU ic520.(control of relays)
Also if the relays open close (after first load) i know that i have cold joint especially on the output connectors.
Keep in mind that the volume control on this units are very sensitive on dust also the hdmi cables on this reciever use a return audio path to monitor the sound so check cables also...Last edited by charis; 04-13-2016, 03:29 AM.Leave a comment:
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