sanyo DP32648 tv will not turn on

[CR Designs]

Re: sanyo DP32648 tv will not turn on

In order to start the power supply and test the inverter you need 2 wires. first wire goes from 5v standby + 1000ohm resistor to pson, then you run a 2nd wire and 1000 ohm resistor from 5v on power supply to stb pin on the inverter. Wire that all up with the main board disconected, and the inverter should turn on and youll see the screen glow (but still be black).

Also you run the 12v bulb between the 12v pin and a ground pin in the same socket (generally using the case as ground would work too, but ive always done it to the ground pin)

Did the 12v bulb test. it held at 5.05v

[CR Designs]

Re: sanyo DP32648 tv will not turn on

The board markins say it suports 2.5amps on the 12v rail. You could connect a 12v bulb such as

http://www.homedepot.com/h_d1/N-5yc1...&storeId=10051

with 20-30w power usage with the main board disconected. Then jump the power supply on and see if the voltage remains within 5% of 12v. Theres probably some cheaper 12v bulbs out there, just make sure the wattage is 20-30w.

If it does you know the main board has a short, Were gonna need a picture of the back of the board to trace the path to find a short. The main boards are fairly cheap ($30), so if you were 100% sure that was the problem, id probably recomend just replacing it unless you are more concered with knowledge then time / profit.

Here's the bulb test on 12 volts it held at 11.77v I told you 5v test on earlier post

[CR Designs]

Re: sanyo DP32648 tv will not turn on

So Cashkennedy what's all this testing telling you?

[cashkennedy]

Re: sanyo DP32648 tv will not turn on

The 12v test with bulb shows a good output for the 12v rail.

The error pin doing .4-.5 volts is possibly an issue. I would need to know what panel is in this set (that might be hard to see since these sanyo sets have such easy to get to boards behind the back door, but the panel label would be on the silver back of the panel beyond the boards and plastic. Possibly knowing the part number for the tcon could tell us the panel maker too.

[CR Designs]

Re: sanyo DP32648 tv will not turn on

The 12v test with bulb shows a good output for the 12v rail.

The error pin doing .4-.5 volts is possibly an issue. I would need to know what panel is in this set (that might be hard to see since these sanyo sets have such easy to get to boards behind the back door, but the panel label would be on the silver back of the panel beyond the boards and plastic. Possibly knowing the part number for the tcon could tell us the panel maker too.

Panel # Sharp LK315T3LA12

[CR Designs]

Re: sanyo DP32648 tv will not turn on

the error pin is labeled err on the inverter, you just measure dc voltage in the 20v range on your meter between the err pin and a chassis screw. Do this while the set and inverter are on / backlights are lit up.

Tested the error pin again it pluses around from 0.00 to 0.52 And finally settles in around o.52

[cashkennedy]

Re: sanyo DP32648 tv will not turn on

I cant find a data sheet for that panel, but on some panels .5v would be an error, this shouldnt be whats preventing the tv from starting though, it would just make it start and do 2 seconds to black.

Someone else might hav experience with sharp panels and know how to find the data sheet, or what the error system used is.

[CR Designs]

Re: sanyo DP32648 tv will not turn on

I cant find a data sheet for that panel, but on some panels .5v would be an error, this shouldnt be whats preventing the tv from starting though, it would just make it start and do 2 seconds to black.

Someone else might hav experience with sharp panels and know how to find the data sheet, or what the error system used is.

Need some help on this one and ideas

[cashkennedy]

Re: sanyo DP32648 tv will not turn on

So i actually own a DP32648, I had been keeping quiet about that, cause i was considering offering you a mainboard for one (since i have a bunch of extra boards for dp32648s) but i left them all in a building i moved out of, and i had to sneak in at night and check which i left there... I couldnt find a mainboard in the box though, just an inverter and a broken psu....

I do have a working DP32648 though that i just hadnt sold yet (been like a year, i hate listing stuff on CL, idk why ...) so i took some measurements...

The 3 voltage regulators in the center of the mainboard should have 6volts on pin 1 , and pin 3 for the 3 are 2.2, 3.3, and 5 volt outputs. I tested the 3 wires comming from the inverter (idk which pins on the main corespond to which pins on the inverter) and i got 0v on the white wire, 3.3v on the next two black wires. (the 2nd two are most likely brightness and blon) If the white wire does corespond to the err pin on yours then your err reading is high.

Some other tests i did with the mainboard not connected to anything i got 50k ohms resistance between the 12v rail and ground, and 60k ohms between the 5v rail and ground. If either of those are significantly (10x) lower then you have a short on the board. My 5v and 12v rail when off and on are very close to perfect (5.01, and 12.1) but the 24v rail that goes to the mainboard read 63 or something idk what thats about.

I took some pictures of the back of the main, but honestly this is like a 3 layer board or more, there were 0 traces going anywhere logical... there are soooo many components on these boards, the whole backside is covered in smt's...

[CR Designs]

Re: sanyo DP32648 tv will not turn on

So i actually own a DP32648, I had been keeping quiet about that, cause i was considering offering you a mainboard for one (since i have a bunch of extra boards for dp32648s) but i left them all in a building i moved out of, and i had to sneak in at night and check which i left there... I couldnt find a mainboard in the box though, just an inverter and a broken psu....

I do have a working DP32648 though that i just hadnt sold yet (been like a year, i hate listing stuff on CL, idk why ...) so i took some measurements...

The 3 voltage regulators in the center of the mainboard should have 6volts on pin 1 , and pin 3 for the 3 are 2.2, 3.3, and 5 volt outputs. I tested the 3 wires comming from the inverter (idk which pins on the main corespond to which pins on the inverter) and i got 0v on the white wire, 3.3v on the next two black wires. (the 2nd two are most likely brightness and blon) If the white wire does corespond to the err pin on yours then your err reading is high.

Some other tests i did with the mainboard not connected to anything i got 50k ohms resistance between the 12v rail and ground, and 60k ohms between the 5v rail and ground. If either of those are significantly (10x) lower then you have a short on the board. My 5v and 12v rail when off and on are very close to perfect (5.01, and 12.1) but the 24v rail that goes to the mainboard read 63 or something idk what thats about.

I took some pictures of the back of the main, but honestly this is like a 3 layer board or more, there were 0 traces going anywhere logical... there are soooo many components on these boards, the whole backside is covered in smt's...

The voltage regulators I got 0.56 on all of them on pin 1 . On pin 3 I got 0.00, 0.00 and 0.48 3 wires from inverter white is err 0.00 next black wire is blon 0.00 next black wire 0.00. What's your meter set to to test 5v rail and 12v rail. When I tested the rails it just jumped and pulsed and went to 0.00 Also I purchased a main board today off E-Bay. But would to keep trouble shooting this board to see whats wrong. Thanks again for your help cashkennedy

[cashkennedy]

Re: sanyo DP32648 tv will not turn on

Well im not expecting your regulators to work, since im pretty sure your mainboard has a short.

To measure the voltages of the rails i set my meter to 20v DC (looks like =-=, do not use AC which looks like ~ ) I put 1 probe to the ground screw on the power supply (or that big peice perforated sheet metal in the middle of the main board, and then connect the other probe to the 5v or 12v pins in the plug. The pins are easy to contact in the plugs on this model, but make sure you get it good and strongly pressured against the metal in the socket of each plug. If you use ground screws as the ground point, they need to actually be attached to the set properly, and fully screwed in. This set kinda has a odd system for grounding, because the boards are all attached to plastic, and thats why the bottom of the mainboard has long peices of metal that need to contact the bottom of the panel , and the screw holes all have metal peices that are a pain in the ass to line up but need to be there or else the screws might not be grounded ...

To measure the resistance of the 5v and 12v, you just unplug everything from the mainboard and put your meter into 200k resistance mode (might have to move your probes from 1 socket to the other, make sure the red probe is in the correct socket for resistance) then touch 1 probe to the large perforated metal shield in the middle of the main board, and the other probe to the pins that corespond to the 5v and 12v rails. the 12v rail is pin 4 from the top, and the 5v rail was 5 from the bottom (when lookign at the set with the mainboard on right, and power supply on left) You should see a reading like 60.5 which means 60,500 resitance when your on the 200k mode.

Earlier you said you get .5 v on the err pin. I assume thats the white wire. You need the backlights and power supply both jumped on to measure the voltage on that pin properly.

You might want to wait to get the main board before you worry about the inverter error signal. Theres a chance that with a working mainboard the error voltage will go away.

[selldoor]

Re: sanyo DP32648 tv will not turn on

Could be a ceramic gone short - see here
https://www.badcaps.net/forum/showthread.php?t=10451

It can take a long long time to test them all.
Sometimes you can hit lucky and it has changed colour - virtually impossible to spot on a picture unless it is a really really clear one.

[CR Designs]

Re: sanyo DP32648 tv will not turn on

measure the resistance of the 5v and 12v, you just unplug everything from the main board and put your meter into 200k resistance mode (might have to move your probes from 1 socket to the other, make sure the red probe is in the correct socket for resistance) then touch 1 probe to the large perforated metal shield in the middle of the main board, and the other probe to the pins that corespond to the 5v and 12v rails. the 12v rail is pin 4 from the top, and the 5v rail was 5 from the bottom (when lookign at the set with the mainboard on right, and power supply on left) You should see a reading like 60.5 which means 60,500 resistance when your on the 200k mode.

Measured resistance at 5v and 12v rail got 23.2 at 5v and 52.6 at 12v

[CR Designs]

Re: sanyo DP32648 tv will not turn on

Well im not expecting your regulators to work, since im pretty sure your mainboard has a short.

To measure the voltages of the rails i set my meter to 20v DC (looks like =-=, do not use AC which looks like ~ ) I put 1 probe to the ground screw on the power supply (or that big peice perforated sheet metal in the middle of the main board, and then connect the other probe to the 5v or 12v pins in the plug. The pins are easy to contact in the plugs on this model, but make sure you get it good and strongly pressured against the metal in the socket of each plug. If you use ground screws as the ground point, they need to actually be attached to the set properly, and fully screwed in. This set kinda has a odd system for grounding, because the boards are all attached to plastic, and thats why the bottom of the mainboard has long peices of metal that need to contact the bottom of the panel , and the screw holes all have metal peices that are a pain in the ass to line up but need to be there or else the screws might not be grounded ...

To measure the resistance of the 5v and 12v, you just unplug everything from the mainboard and put your meter into 200k resistance mode (might have to move your probes from 1 socket to the other, make sure the red probe is in the correct socket for resistance) then touch 1 probe to the large perforated metal shield in the middle of the main board, and the other probe to the pins that corespond to the 5v and 12v rails. the 12v rail is pin 4 from the top, and the 5v rail was 5 from the bottom (when lookign at the set with the mainboard on right, and power supply on left) You should see a reading like 60.5 which means 60,500 resitance when your on the 200k mode.

Earlier you said you get .5 v on the err pin. I assume thats the white wire. You need the backlights and power supply both jumped on to measure the voltage on that pin properly.

You might want to wait to get the main board before you worry about the inverter error signal. Theres a chance that with a working mainboard the error voltage will go away.

When I jumped the power on 5v,12v and 24v were good

[CR Designs]

Re: sanyo DP32648 tv will not turn on

Cashkennedy
you said you had some parts for this TV,do you have a base?

[CR Designs]

Re: sanyo DP32648 tv will not turn on

Could be a ceramic gone short - see here
https://www.badcaps.net/forum/showthread.php?t=10451

It can take a long long time to test them all.
Sometimes you can hit lucky and it has changed colour - virtually impossible to spot on a picture unless it is a really really clear one.

Selldoor, please send a picture of ceramic to confirm what capacitor looks like. If there the ones i think they are on this board they are very very small MICRO!How do you test them

[selldoor]

Re: sanyo DP32648 tv will not turn on

Selldoor, please send a picture of ceramic to confirm what capacitor looks like. If there the ones i think they are on this board they are very very small MICRO!How do you test them

All you ask is in the link I included in my post
To narrow it down a bit further specifically here

https://www.badcaps.net/forum/showpo...1&postcount=23

and in his picture of the main/logic board top

[CR Designs]

Re: sanyo DP32648 tv will not turn on

All you ask is in the link I included in my post
To narrow it down a bit further specifically here

https://www.badcaps.net/forum/showpo...1&postcount=23

and in his picture of the main/logic board top

I read that I just wanted to confirm those were what you were talking about. How do you go about soldering something that small and there all over this board. you need magnification to see them

[selldoor]

Re: sanyo DP32648 tv will not turn on

I thought you were a jeweller? get your loupe on

[CR Designs]

Re: sanyo DP32648 tv will not turn on

I thought you were a jeweller? get your loupe on

I am and I have been using it a lot along with my head gear. How do you solder on something that small without all the other components around it coming lose?With jewelry work with a torch I know how to go about it But with a soldering iron and low melt solder Hmmmm.