Polaroid TLA-04641C clicking relay

[pop70458]

The Tv's relay keeps clicking and the voltages fluctuate. The clicking relay is at location RE1.

on/ off 0.8V--5.2v
+5VSB 0.8V--5.2V
12V 0.8V--12.2V
24SP 0.8V--25V
24V 0.8V--25V

Main filter cap goes to 462V and drops with relay clicks.

Thanks for the help.

[budm]

Re: Polaroid TLA-04641C clicking relay

Can we get side view of the power supply board? There should be small stratup-running lytics caps under the heatsink for the standby power supply section.
Unhook the cable between the main board and the power supply board and then power up the power supply board by itself and check to see if 5Vstby will be steady 5V or not.

"Main filter cap goes to 462V" What did you use for the GND ref for the meter to measure that filter cap Voltage? Chassis? You need to measure right between the two legs of the cap because you are making measurement in the HOT side circuit.

[pop70458]

Re: Polaroid TLA-04641C clicking relay

The 5vsb is a steady 5.1v with the mainboard cable unhooked. The main cap is at 170.1v with the mainboard cable removed.


When i got the 462v I measured the main filter cap while the relay was clicking. It would go to 462v then start dropping and go back up when the relay would click. I used the legs of the main filter cap when i got the 462v reading.

[dskall]

Re: Polaroid TLA-04641C clicking relay

Check all caps under heatsinks for bulging

[budm]

Re: Polaroid TLA-04641C clicking relay

https://www.badcaps.net/forum/attach...2&d=1506707143
There should be small caps under the second heatsink from the left.
If you truely having 462VDC between the two legs of the main filter cap which is rate at 450 VDC then you have problem with the voltage regulation of the PFC booster circuit problem, it should cause the protection circuit to kick in otherwise that main cap will blow up big time.

[pop70458]

Re: Polaroid TLA-04641C clicking relay

The relay near where the ac voltage comes in is constantly clicking.

[vinceroger69]

Re: Polaroid TLA-04641C clicking relay

have you got another multi meter you can confirm the main capacitor voltage with as 462v is very high like budm says surprised it has not exploded yet

[pop70458]

Re: Polaroid TLA-04641C clicking relay

I checked it with another meter it will go somewhere between 442v or 435v for less than a second and then the relay will click and the voltage starts to drop until a hard click. The cycle just keeps repeating itself. There is a 47uf 50v cap and a 10uf 50v cap under the heat sink you referred to earlier.

[budm]

Re: Polaroid TLA-04641C clicking relay

The relay is clicking because your standby 5V is not steady for running the main board so the main board is sending out pulsing PS-ON signal instead of steady DCV of 2V or more.
Those two small caps are startup/running caps for the standby power supply section, if they are bad they can cause the STBY 5V to be unstable under load, so you can try replacing them first to see what happen.
Over output Voltage of PFC circuit is another problem, if the reading is true for sure.

[pop70458]

Re: Polaroid TLA-04641C clicking relay

I replaced the startup caps and now it powers on. I will replace all of the caps.

I would like to thank everyone for their help.

[dskall]

Re: Polaroid TLA-04641C clicking relay

What is voltage on main cap now?

[budm]

Re: Polaroid TLA-04641C clicking relay

what is voltage on main cap now?

+10

BTW, bad design to put cap under the heatsink where things get hot.

[pop70458]

Re: Polaroid TLA-04641C clicking relay

The main filter cap is 410.6v with the tv powered on.

[budm]

Re: Polaroid TLA-04641C clicking relay

The main filter cap is 410.6v with the tv powered on.

That is on the high side, I expect 400VDC at the most, typical Voltage is 380~400VDC.

[Jimmy60]

Re: Polaroid TLA-04641C clicking relay

Glad I found this thread! budm is the BOMB!!! He was dead on with his diagnosis.

Thanks Guys!!!

[Jimmy60]

Re: Polaroid TLA-04641C clicking relay

Man those two caps are not easy to change!!!