42' plasma....tatung

[PlainBill]

Re: 42' plasma....tatung

Problem with these part numbers on board they are internal PCB part numbers not part numbers for complete assy (most website that resells used parts incorrectly refer to internal PCB part numbers) and is not in samsung catalog. And unfortunely I don't have the model number you gave to me as it does not exist in samsung's website because it is not a full model # or unique model made for extremely specific area. Or it was produced more than 5 years ago when samsung transitioned from paper to webpage and PDF service manuals.

The pictures you showed us is X drive (on right side, rarely fail, check fuses). The left side is Y-drive/Y buffer (most common to fail), bottom row is Z-drive/buffer (extremely rare to fail).

Cheers, Wizard

According to HDTV Solutions, this TV went out of production in June of 2006. I always appreciate your advice and assistance; just the fact that you mentioned the failure probability of the various boards is a help.

I understand that by the nature of your job you are tightly tied to the true part numbers. Without the restraints and resources you have available, I make do with whatever I have available.

However, in this case I don't think it will be possible to fix the TV.

PlainBill

[medamotcha]

Re: 42' plasma....tatung

ok,thx...but im going to try a differnt meter to make shore..i like the needle meters my self.....let me try with a diff..ok?..and ill get back..if i dont' well i have another tv..lol but im going to give up yet...so far it was to easy to give up...what u have shown me..i want to get deep in this....if i cant get any volts to the y and x board....y only get 20 volts.swinging high and low...what would make that do that? please give me a best guess...thair still stuff that i can do to this mother board..test every cap and resister and transister...i did some reserch on the ..i think its called the transister...black things with the screew thew it..and have the three legs..i was learning how to test....how about the dieods..but that looked all good but did not test....
thx for your time..ill post my other tv and a day or sothx



oh edit,im going to try what wizzard too also ,it couldent hurt...and if i have to put every cap out to test ,thats the only way to get a true reading...so ill start with the big ones first....my gut tells me its in the mother board..where you showed me.and thats what tatung support said.. when i called them for repair .now im going.... later

[medamotcha]

Re: 42' plasma....tatung

hey guys still got questions..please...how do you test a dieode...can you tone out ?or i have to take out?and test?

[medamotcha]

Re: 42' plasma....tatung

ok guys i found it....check this out..i studyed this all day..and yes the mother board is toast...un less u know what to look for and the led codes...remember the first post..about the led lights..well thay had a number
8001-8002...well i found out the thair curcuts...so thair more to them..so i would look around,what ever had 8001 next to it or the 8002section.and would look around thair.....that when i seen the hot side and cold side...hot side..is the power side....the cold side is the y and x boards.....now y wasent the cold side turning on when i hit the power...well i looked around the white boundry....and started to see...and tested them.......all but one is good...you can see them a little disfigerd.....thair usely run about low ressistence about 1 ohm....idident get nothing...but one...but im going to replace all...to be safe.and whats one more....to do it right.......look i drew a diegram..so you could see...and pdf file that i study...and explained and the scmatics...drawing..........i think thair about 8 or 10 caps ...that are bad..i tested everthing and around the transiter(led8001-2)......you see...with out the low end caps thairs no ground.......becouse all this has something to do with the screws down the board...bad ground was swing the meter up and down ....wouldent it...or amp up to 170 volts and hold or the safty operation
well.....i have to order...than well see ..but im possative....the meter dont lie

[medamotcha]

Re: 42' plasma....tatung

something is wrong.....with my meter...1 min i wont get a reading and another i will...will a cap do that?im getting a new meter tommorw.
we might have to scratch the whole thread...couse it would be wrong
but i did learned alot from yall already

[medamotcha]

Re: 42' plasma....tatung

ok guys ive been doing some home work and i found something real cool info
so i can ask the right questions..
but the info that is in red....y my meter is swinging up and down







* Bad startup circuit - initial base (gate) drive is often provided by
a high value, high power resistor or resistors from the rectified
AC voltage. These can simply open for no good reason.

Symptoms: In this case the supply will appear totally dead but all
the semiconductors will check out and no fuses will blow. Check the
startup resistors with an ohmmeter - power resistors in the AC line
input section. Warning: there will be full voltage on the main filter
capacitor(s) - 1X or 2X peak or around 160 or 320 VDC depending on design.
Discharge before probing.

* Dried up capacitors - either input or output side.

Symptoms: The main filter capacitor may dry up or open and cause the
output to be pulsing at 60 (50) or 120 (100) Hz and all kinds of
regulation problems. Measure voltage across main filter capacitor(s).
If the reading is low and drops to a much lower value or 0 instantly
upon pulling the plug, then one of these capacitors may be open or dried
up. If you have an oscilloscope, monitor for ripple (use an isolation
transformer!!). Excess ripple under moderate load is an indication of
a dried up or open capacitor.

In extreme cases, a main filter capacitor with greatly reduce capacity
or that is totally open may result in failure of the switchmode transistor
and a dead supply that blows fuses or fusable resistors. Therefore, it is
always a good idea to test the electrolytic capacitors whenever repairing
a SMPS that has blown its switchmode transistor.

Capacitors in the low voltage section may fail causing regulation problems.
Sometimes there are slew rate limiting capacitors which feed from the
primary output to the regulator controller to limit initial in-rush and
overshoot. A failure of one of these may mess up regulation at the very
least. For example, excess leakage may reduce the output of the main
output (and as a consequence, all the others as well).

Where a controller like a UC3842 is used, a failure of the capacitor on
its Vcc pin may result in a aborted startup or cycling behavior as it is
starved for juice each time it pulses the switchmode power transistor:



i would like yall take on this i think this is a good question to ask..please
wher is the filter cap.....left side i think.and over a little ot the right...am i right ?

[Wizard]

Re: 42' plasma....tatung

Please cite this passage.

Sounds like you taken it from electronic repair FAQ by Sam's?

Cheers, Wizard

[medamotcha]

Re: 42' plasma....tatung

Please cite this passage.

Sounds like you taken it from electronic repair FAQ by Sam's?

Cheers, Wizard

i wanted to show yall that im learning something and wont give up to easy..i have the whole thing FAQ but i dint know where i got it but im reading it and learning...and i have to ask the right questions....can i buy the kit...for my power board -IC curcit...all the different parts .into one kit?...when i test the ic akk around the board...on the transisters....with the 3 leg....the a lot of them test out bad...one side is good but the other ether 0L or a different ohms than what its suppost to be..and when i reverse the leads i get the same reading...

[medamotcha]

Re: 42' plasma....tatung

witch chassis do i have?...it find on the other power board...on the bottom...it will say assemblycode XXXXXXXXXXX? how do i convert the stock part#...to usa?

[medamotcha]

Re: 42' plasma....tatung

ok guys i have an esr meter...good caps will read 0..and bad caps will give a high reading or bouncing reading?please lt me know..

[retiredcaps]

Re: 42' plasma....tatung

Any progress on this AKAI?

The local ad has this AKAI PDP4273M for $50 each (3 of them) and the seller is someone who fixes LCDs, but not plasmas, lists "There is only red led on it, no powering up".

I'm thinking of possibly getting this unit for fixing. I realize there a huge difference between fixing the computer LCD monitors (so far by replacing bad caps) and TV plasmas and I'm still waiting for my DMM. I will be a total newbie using a DMM, but I'm eager to learn about DMM and plasmas.

According to some info I found, it weighs about 76 pounds without a stand.

I think I have a variant of this screen.

Model: AKAI PDP4273M

At first glance through the vent holes the capacitors look OK.

Symptoms:
In any case, I'll deal with it when I have the will. The thing must have a thousand screws and weighs a ton.

[nairb101]

Re: 42' plasma....tatung

I acquired a Tatung 42" Plasma (well, kept it out of the trash, at least temporarily). A little reading and checking revealed a shorted upper Y buffer board, a shorted transistor and a couple open power resistors on the Y mainboard. It seems that Toshiba plasmas of similar size and vintage use these boards, and I was able to download an appropriate Toshiba Service Manual. The photos show the Samsung boards on the chassis, but the schematic doesn't cover the boards at all! Does anybody have a schematic of these boards?
Thanks!