HELP!! Polaroid 3211-TLXB

[MagicSmoke]

Re: HELP!! Polaroid 3211-TLXB

It may be the backlight is still on (visible through holes in back shield) or a fault led on the main?

[mopower440]

Re: HELP!! Polaroid 3211-TLXB

It must be the backlight. There is no fault led on the boards, ive looked. This is a white light that can be seen through the holes in the shield like you said, and its on when the tv is working also.. any idea why when it goes dead the backlight stays on?

[budm]

Re: HELP!! Polaroid 3211-TLXB

If you have backlights but nothing is showing on the screen then you need to find out if you have DC Voltage feeding the TCON board, may be the LVDS cable is loose or has dirty contacts.

[mopower440]

Re: HELP!! Polaroid 3211-TLXB

ya, when watching it and it decides to go dead, the tv just shuts off..no sound, no picture, and the little red/blue led on the front also either goes out completely or goes to a dim red, but the backlight stays on..

[MagicSmoke]

Re: HELP!! Polaroid 3211-TLXB

If the standby led goes out, then PSU is losing 5vstby or the 12v line.


Edit.... Or something on mainboard getting hot and failing.

[budm]

Re: HELP!! Polaroid 3211-TLXB

"ya, when watching it and it decides to go dead, the tv just shuts off..no sound, no picture," OK, that is more details.
So some how the PS_ON and the BL_ON are still present when it's bad, but that means the stby supply is working.
As we suggested before, you need to take voltage readings on the connectors when it is working and when it does not work to find out what is missing, It sounds like the main board is the problem.

[cashkennedy]

Re: HELP!! Polaroid 3211-TLXB

So someone asked me to fix a unbranded if32 (its the same polaroid just unbranded, probably after they realized these models were not even sellable under any of their total crap brands like element, proview, polaroid, bush...)

TV will light up red off led and wont power on (blue led), power supply could be forced on, all voltages are good, backlight works fine. (This isn't the mlt666 that has the 2 bad caps , but one of the other versions of this set)

I ordered a new mainboard from shopjimmy based on the part number sticker on back of board, of course the silk screen model and revision number on board doesn't match... With their board the set will turn on / turn on the backlights, but I get nothing on the screen. I asked for a replacement board, and once again they sent me one that doesnt match the silk screened model and revision, but does match the part number on label. They sell the control box as well and it clearly states that it goes with 24v lvds. The boards they sent me generate 12v on the power pins of the lvds cable.

The 2 boards they sent have modifications to the bottom aswell, apparently there was a recall on the mainboard I believe and they were repaired at peoples houses by adding a ton of jumpers between 2 ground regions, or at the factory.

I tried to find the panel spec sheet for auo t315xw02 v3 but even though this site "beyondinfinite" has millions of auo spec sheets they don't have this model.

Can anyone find the spec sheet, or tell me a way I can determine if the tcon needs 24v power. Ill post a picture of the tcon tonight, so tired of this tv I might just wire 24v to the tcon manually and see what happens...

24v seem pretty bizarre to send to a tcon as well, but hey why not? maybe it saves them 2 12" 32guage copper wires from being in the lvds cable.

[cashkennedy]

Re: HELP!! Polaroid 3211-TLXB

So I got the tcon out and didn't see anything discernable on the markings at first glance other then the fuse (f1), I tested it and it was actually bad, so I soldered a wire to it since I don't keep / or like burning up expensive fuses on crappy sets. powered it on, got a extra pop. set wouldn't turn off till I promptly unplugged it. slight burning plastic smell from tcon. took the tcon out, and jumper is still there, and ... now NOW I notice it has a 5v test point like 1 cm from the fuse... so apparently this 24v lvds probably should be a 5v lvds and not 12v like the boards they sent me are outputting...


Any idea what part I burned out when I jumpered the fuse?

[cashkennedy]

Re: HELP!! Polaroid 3211-TLXB

http://assets.shopjimmy.com/media/ca...xaph-top_1.jpg

if you look closely at the top of the lvds connector in the center of the mainboard, there is are 2 jumpers next to that region, I'm thinking maybe those control what power is used to feed the tcon? might give it a shot with 1 of the mainboards and lvds cable disconnected

[cashkennedy]

Re: HELP!! Polaroid 3211-TLXB

so the reason I never noticed that jumper before is because its hidden beneath globs of white glue. The boards I got from shop jimmy were all connecting the 12v to the tcon, vs my board had the jumper on the 5v section.... youd think shop jimmy would have figured this shit out / warn people.

So I could buy a new tcon for $10, but is that the only difference between the mainboards?

There is a green sticker with a 4 digit code ontop of a chip in the lower left in the shop jimmy pic. Is that the programmable flash? at least the boards they sent me come with the same 4 digit code on that sticker, I'm hoping that means both boards have the same firmware?

[cashkennedy]

Re: HELP!! Polaroid 3211-TLXB

So I replaced the t-con, set the mainboard I got from shop jimmy to send 5v power to the tcon, put it most of the way back together, found a polaroid remote I had from another POS polaroid set...

But it doesn't work properly, the colors are all off...

Would yall assume that the fact that the mainboards have 12v jumper glued down and a different part number silk screened onto the board indicates shop jimmy is sending me the wrong mainboard? or do yall think I just happened to get a defective tcon / have the ribbon cables screwed up (ive reseated them once to make sure that wasn't the issue)/ or some other issue?

Pictures show the color issue. Sound and refresh rate are both fine. Menus are also screwed up, so not likely to be a symptom of just 1 input.

[budm]

Re: HELP!! Polaroid 3211-TLXB

That looks like wrong GAMMA Voltage ref on the T-CON.

[cashkennedy]

Re: HELP!! Polaroid 3211-TLXB

Is that something I can measure from a test point on the t-con? I also never found a manual on this panel model, so not sure if ill know what voltage I need.

Does the gamma voltage come through the lvds? or is it created on the tcon based on its own design for the panel?

[budm]

Re: HELP!! Polaroid 3211-TLXB

GAMMA Voltage reference IC is on the T-CON board, AS15, AS19 are typical GAMMA ICs used in lots of T-CON. There should be test points on the T-CON board for testing the T-CON Voltages, there should be around 15~22 test points on the board for GAMMA Voltages.

[cashkennedy]

Re: HELP!! Polaroid 3211-TLXB

Yeah there are clearly 21 or so test points on the tcon, you can see them in the first of the tcon pictures I posted above. What voltages am I to expect to verify it is functioning / broken?

[budm]

Re: HELP!! Polaroid 3211-TLXB

Just take the DCV readings and list them in sequence so we can see the Voltage pattern.

[cashkennedy]

Re: HELP!! Polaroid 3211-TLXB

So from the clearly labeled gamma points along the top (which has a few missing numbers?, unless I am not seeing them elsewhere on the tcon)

gamma 1 = 15.47 vdc
gamma 2 = 15.31
gamma 7 = 10.32
gamma 8 = 10.04
gamma 9 = 9.82
gamma 10 = 8.44
gamma 11 = 8.22
gamma 12 = 6.70
gamma 13 = 6.44
gamma 14 = 5.05
gamma 15 = 4.77
gamma 16 = 4.46
gamma 21 = .460
gamma 22 = .350

So cause they decided to make the control box a separate unit with a huge connector for speaker / button board / ir / inverter control I had to turn the unit on then pull that 1 huge connector appart so I could get the control box out of the way to actually take readings on the tcon. Doesn't seem to have affected the set negatively, but there was a lot less inverter board load since the bulbs turned off when I pulled the control box out. The 5v power input to the tcon read 4.77 vdc or so.

[johnboy1313]

Re: HELP!! Polaroid 3211-TLXB

What does your menu look like when no source is connected?

https://www.badcaps.net/forum/showthread.php?t=27876

[cashkennedy]

Re: HELP!! Polaroid 3211-TLXB

My menu is garbled with no source connected. The startup logo is very unvibrant. So I'm pretty sure its not just something wrong with the tv tuner. I do think it is the mainboard though, because of the fact that the mainboards have different screen printed model numbers, and originally came with a jumper glued down that was outputting 12v power instead of 5v.

Would like to hear Budm's opinion on those gamma chip readings though.

[budm]

Re: HELP!! Polaroid 3211-TLXB

You need to find the GAMMA 3, 4, 5, 6, 17, 18, 19, and 20. What you shown so far are OK but it takes only one bad GAMMA Voltage to mess up the display.