Badcaps.net Forum
Go Back   Badcaps Forums > Search Forums
Register FAQ Calendar Search Today's Posts Mark Forums Read

Showing results 1 to 25 of 500
Search took 0.02 seconds.
Search: Posts Made By: R_J
Forum: Troubleshooting Computer Displays Yesterday, 07:47 PM
Replies: 10
Views: 161
Posted By R_J
Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

Ken256 has a good point about the heater cap (now I remember) C641 (100f/16v) I do remember changing these quite often. C621 (47f/250v) sounds familiar as well.
In fact I would replace that C641...
Forum: Troubleshooting Computer Displays Yesterday, 01:02 PM
Replies: 10
Views: 161
Posted By R_J
Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

What equipment do you have for checking this monitor? do you have a multimeter? If you do, have you checked any of the voltages from the power supply?
Forum: Troubleshooting TVs and Video Sources Yesterday, 12:55 PM
Replies: 6
Views: 124
Posted By R_J
Re: ID parts & troubleshoot a short - UN75F6300AF Samsung TV

When the cap CP814 shorted, did you check the mosfet it is across? I would check all fets in that area. Although NT801s is cracked it is likely still working, check its resistance.
Forum: Troubleshooting Audio Equipment Yesterday, 12:14 PM
Replies: 2
Views: 135
Posted By R_J
Re: need help to know what is the ohm of this switch

Check the resistance across the two outside connections, then measure the size of the control and shaft, It looks like a 8mm or 10mm pot. If the pot directly controls the audio signal you will need...
Forum: Troubleshooting Computer Displays Yesterday, 11:20 AM
Replies: 10
Views: 161
Posted By R_J
Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

It won't be a mylar cap that is causing this, It is likely a cap on the supplies for the video output ic.
This is the same 19VC chassis from elektrotanya.com
I have'nt worked on these for a very...
Forum: Troubleshooting TVs and Video Sources 01-25-2021, 07:24 PM
Replies: 29
Views: 322
Posted By R_J
Re: Insignia NS-39L700A12 backlight transformer high pitched wine

There could be a fault with the led's causing the problem, carefully remove the lcd panel & diffusers and see if there are some bad led's.
Forum: Troubleshooting Audio Equipment 01-25-2021, 05:28 PM
Replies: 8
Views: 93
Posted By R_J
Re: Definitive Technology Subwoofer repair

If the main caps were replaced and now you have a different problem, I suspect this is a double sided board and the feed-tru's were pulled out with the original caps. remove the new caps and inspect...
Forum: Troubleshooting Computer Displays 01-25-2021, 05:16 PM
Replies: 4
Views: 72
Posted By R_J
Re: AOC Q3279VWF, no power

The parts on the hdmi line are for protection on the data lines, they can be removed for testing, the data lines should be straight through under the udfn-10 (DFN2510-10)esd protector. Like mentioned...
Forum: Troubleshooting Audio Equipment 01-25-2021, 04:24 PM
Replies: 8
Views: 93
Posted By R_J
Re: Definitive Technology Subwoofer repair

Upload the pictures to the forum using Go Advanced, then click the paperclip to attach the pictures. What's the model number?
Forum: Troubleshooting TVs and Video Sources 01-25-2021, 04:05 PM
Replies: 29
Views: 322
Posted By R_J
Re: Insignia NS-39L700A12 backlight transformer high pitched wine

L601 is NOT a transformer, it is just a coil (inductor) In this case it is used to boost the led voltage, Is the base supply voltage ok and clean? If the supply is not filtered properly, there can be...
Forum: Troubleshooting TVs and Video Sources 01-25-2021, 02:41 PM
Replies: 54
Views: 998
Posted By R_J
Re: E470VA with a PLHH-Y009A - no power

A mosfet has 3 leads, a DRAIN, a SOURCE and a GATE, The "gate" of the mosfet has parts connected to it, check them.
Forum: Troubleshooting Audio Equipment 01-25-2021, 12:45 PM
Replies: 8
Views: 78
Posted By R_J
Re: Switched speaker impedance selector w/ Yamaha HTR-5740 RX-V450 powered on!! Probl

Normally the impedance switch is right on the outputs and switches the actual output. but not in this case, it just increases the voltage to supply more current with the lower impedance speakers....
Forum: Troubleshooting TVs and Video Sources 01-25-2021, 12:35 PM
Replies: 29
Views: 322
Posted By R_J
Re: Insignia NS-39L700A12 backlight transformer high pitched wine

18 volts is fine for the main & pfc ic's The emitter voltage will be higher in standby because the transistor is turned off. So is the vcc voltage in standby 21.5v or is iI changing? In standby, N503...
Forum: Troubleshooting Audio Equipment 01-25-2021, 12:15 PM
Replies: 8
Views: 78
Posted By R_J
Re: Switched speaker impedance selector w/ Yamaha HTR-5740 RX-V450 powered on!! Probl

In this model, the switch tells the microprocessor input to change between 4/8 Ω which changes the voltage supplied to the output transistors via the circuit on page 82 (pdf 47) so switching the 4/8...
Forum: Troubleshooting Computer Displays 01-25-2021, 10:50 AM
Replies: 10
Views: 161
Posted By R_J
Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

I would start by checking the screen supply voltage cap. I believe it is in the power supply for the 220vdc (4.7f/250vdc) Also check the caps on the 80vdc line. These supply the video output ic
I...
Forum: Troubleshooting Audio Equipment 01-25-2021, 10:43 AM
Replies: 8
Views: 78
Posted By R_J
Re: Switched speaker impedance selector w/ Yamaha HTR-5740 RX-V450 powered on!! Probl

If the amp is still working, you are ok, just don't switch it when the amp is on because you could damage the output transistors and maybe more.
in this case you got lucky. The service manual is too...
Forum: Troubleshooting TVs and Video Sources 01-24-2021, 08:20 PM
Replies: 54
Views: 998
Posted By R_J
Re: E470VA with a PLHH-Y009A - no power

You need to check the ones in the gate circuit, when the fet's short, they can supply the 160v from the drain, through the gate and damage the gate drive components, so if you replace the fets, and...
Forum: Troubleshooting TVs and Video Sources 01-24-2021, 07:18 PM
Replies: 29
Views: 322
Posted By R_J
Re: Insignia NS-39L700A12 backlight transformer high pitched wine

If the 18v is stable then it should be ok, if it is slow to build up to 18v then there is a problem. To be sure of the voltage I would need the part numbers on N504 & N501
Forum: Troubleshooting TVs and Video Sources 01-24-2021, 06:58 PM
Replies: 29
Views: 322
Posted By R_J
Re: Insignia NS-39L700A12 backlight transformer high pitched wine

I asked for the emitter & collector voltages to see if the ic's had the proper vcc, Since you did'nt post it here, I suggest you look up the ic's datasheet and see if they are correct.
Forum: Troubleshooting TVs and Video Sources 01-24-2021, 05:41 PM
Replies: 54
Views: 998
Posted By R_J
Re: E470VA with a PLHH-Y009A - no power

I would check the diodes and the resistors as well
Forum: Troubleshooting TVs and Video Sources 01-24-2021, 02:17 PM
Replies: 29
Views: 322
Posted By R_J
Re: Insignia NS-39L700A12 backlight transformer high pitched wine

If the transistor, which I am guessing is V503 was open, the tv would not operate at all. It is best to check the emitter and collector voltage when the tv is turned ON, Using HOT GROUND. this will...
Forum: Troubleshooting TVs and Video Sources 01-24-2021, 11:25 AM
Replies: 54
Views: 998
Posted By R_J
Re: E470VA with a PLHH-Y009A - no power

EY stands for Eyelet, NOT the component. I suggest you replace the shorted ones and then check the other components. If Q709 was shorted, I suspect it was Q708 that was also shorted. These are the...
Forum: Troubleshooting TVs and Video Sources 01-23-2021, 09:08 PM
Replies: 54
Views: 998
Posted By R_J
Re: E470VA with a PLHH-Y009A - no power

Yes, the one is shorted, the location is Q70x. "one of the items" doesn't tell me which one, I need to know so I can see what else it might have damaged.
To get a short between Hot ground and 160vdc...
Forum: Troubleshooting TVs and Video Sources 01-23-2021, 08:01 PM
Replies: 29
Views: 322
Posted By R_J
Re: Insignia NS-39L700A12 backlight transformer high pitched wine

Is this V503???? Explain "dead", shorted, open, leaky ? If it is this transistor it is the vcc switch for the main and pfc ic's
Slow turn on is likely due to bad caps, C536 & C531, standby startup...
Forum: Troubleshooting TVs and Video Sources 01-23-2021, 04:28 PM
Replies: 54
Views: 998
Posted By R_J
Re: E470VA with a PLHH-Y009A - no power

Try checking them, but you will likely need to unsolder one of the drain or source leads to be sure.
Showing results 1 to 25 of 500

 
Forum Jump


Badcaps.net Technical Forums 2003 - 2021
Powered by vBulletin ®
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 06:23 AM.
Did you find this forum helpful?