TNPA5623 schematic Panasonic needed

[bkeltm]

Re: TNPA5623 schematic Panasonic needed

For others with pad damage: it appears to work with end pins (4&5, shown w/ X's in pict) not connected. For me, pad 4 came off with chip, pad 5 while i was scraping the charred board between pins - it just jumped off the board. After scraping around and finding no traces, and based on this page, put the chip on w/ those legs dangling. TV has been working for an hour so far.
Reminder: bottom of IC152 is a metal plate that solders to the board.

[badly]

Re: TNPA5623 schematic Panasonic needed

I had a similar issue with a missing pad for the IC. Can confirm that the TV functions when pins 4 and 5 (the left hand side two) are left not connected.

Pins 1-3 can be wired pretty much straight upwards on the board (assuming you're only missing the pads themselves and not the trace above them).

Pin 8 likewise can be wired straight down.

Whereas pins 6 and 7 at the bottom are both wired into the same trace below that runs all the way to the R051 resistor that you no doubt are also replacing, so just attaching to anywhere along that trace should get you up and running.

Remember that you also need to attach the thermal pad at the back of the chip to the board below.

[meyerpflug]

Re: TNPA5623 schematic Panasonic needed

I purchased the SS Board Component Repair Kit from SJ but I messed up one of the pads on the IC (pin 4). I believe this is a ground but would like to verify this by checking the schematic/pinout for this IC (BD8694 1521). Can anyone provide a datasheet for this chip or a better mfr/part number? Google searches do not bring up anything worthwhile using keyword BD8694.

[dgewertz]

Re: TNPA5623 schematic Panasonic needed

I may cave and get the cheapy hot air rework station to pull the chip and not do any more damage...don't see how else to get to the solder under the IC.

Martino,
Just looked at your post again...do the red x's on your board mean no connection?

[Alastair E]

Re: TNPA5623 schematic Panasonic needed

Method I USED to use was some thin Stainless-steel or enammelled wire thread under the row of pins fixed to the board at one end, and after adding a little fresh solder to the row, heat the first pin while applying LIGHT pressure to the wire's loose end where it would be drawn under the pin and lifting the pin upwards.....

Light pressure and it'll unzip the pins from the board, as you move the iron along...

This Horrible Unleaded CRAP solder they make 'em with these days doesn't work so well with this method though, and is no good for chips that are soldered on a pad underneath....

--The old method of a new Stanley-knife to cut the pins from the package sometimes has its place, but great care is needed not to damage the tracks under where you're cutting...

[tw2005]

Re: TNPA5623 schematic Panasonic needed

Thanks....weird because I checked the component alone and dont see that short (crappy multimeter leads perhaps).

Does the solder flood and wicking method work well to remove the IC? I dont have a hot air tool unfortunately

not always easy to tell if those driver ICs are good that way, best option is to replace it if the parts it drives have failed

Neither do I , but I use 2 soldering irons, flood both sides so the solder covers all 4 pins each side, then heat both sides together so the solder is flowing both sides and then just use the tip like tweezers to flick or lift it off.

Failing that you may be able to cut the pins with a sharp blade to cut the legs against the case , remove the body then desolder each pin, risk there is if the leg twists as it's cut the track may tear or lift.

Or a very fine pair of sharp cutters may get close enough to snip each leg at the casing and same desolder each leg

avoid too mush heat for too long as that too will delaminate the track from the board.
dewicking may work or heat each leg and lift it free from the board whilst the solder is liquid, maybe be tight. Brute force or forcing things to lift off will always tear the pad

flowing fresh leaded solder first helps, as the lead free is pretty hard and higher temp. will assist in getting heat in quicker , less stress on the tracks

before you start , make sure you work out which is pin 1 on the part and where pin 1 is on the board for correct orientation

[dgewertz]

Re: TNPA5623 schematic Panasonic needed

Thanks....weird because I checked the component alone and dont see that short (crappy multimeter leads perhaps).

Does the solder flood and wicking method work well to remove the IC? I dont have a hot air tool unfortunately

[tw2005]

Re: TNPA5623 schematic Panasonic needed

Just removed D041 from the board; the component is not shorted, but the throughholes on the board for legs 1 and 3 are shorted.

Is that normal??

if you checked the diode you should also find 1 & 3 will give same result, yes normal. Legs are A -K -A so A-A (anode-anode )will show short

The SJ kit I see includes the 8 pin driver IC. If you have it i would replace it or accept you may have to start all over again with a new kit

[dgewertz]

Re: TNPA5623 schematic Panasonic needed

Just removed D041 from the board; the component is not shorted, but the throughholes on the board for legs 1 and 3 are shorted.

Is that normal??

[dgewertz]

Re: TNPA5623 schematic Panasonic needed

Just found this thread, trying to repair a TNPA5623 with my amateur grade tools.

I bought the ShopJimmy kit and replaced R051 and D041 and Q051. The old Q051 was shorted, but D041 was not. Now that I have the new D041 in the board, legs 1 and 3 are shorted.

Is it possible that my soldering iron somehow damaged D041, or the pads below it? I am leery to connect up the board and blow something up, doesnt seem like these 2 legs should be shorted (and the new component was not shorted).

I did not replace the 8 pin IC. Could that somehow be causing this issue?

[Alastair E]

Re: TNPA5623 schematic Panasonic needed

If you are anything like me Tom, I do up a set--say, like that LG 42PC1DA use it for a while after doing all sorts to it with its IPM's etc, get bored and then will probably replace it with the latest project set!

Got my thoughts on that Pan TH-42PX70 in the garage--Just clearing the decks to have a go at that!
--We see what sorta mess I can make of it!

[tom66]

Re: TNPA5623 schematic Panasonic needed

I really want to get one of these -- trouble is, I'm not sure I would be able to sell it! The PQ is excellent.

[martino]

Re: TNPA5623 schematic Panasonic needed

i know Sold it for good money too!!!

[Alastair E]

Re: TNPA5623 schematic Panasonic needed

Well,it took a bit of creative soldering,this time NOT at 3am and Tv is up and running
Tested,zipped up and TV sold

Well, You Cant Fault That,-- Can ya!

[martino]

Re: TNPA5623 schematic Panasonic needed

Well,it took a bit of creative soldering,this time NOT at 3am and Tv is up and running
Tested,zipped up and TV sold

[tw2005]

Re: TNPA5623 schematic Panasonic needed

I'm gonna make that rule on a wooden sign and hang it above my workstation...!!!

Sure, I believe you.

[martino]

Re: TNPA5623 schematic Panasonic needed

My rule: soldering iron goes away at 10.30 pm. No more soldering past then.

I'm gonna make that rule on a wooden sign and hang it above my workstation...!!!

[tom66]

Re: TNPA5623 schematic Panasonic needed

My rule: soldering iron goes away at 10.30 pm. No more soldering past then.

[martino]

Re: TNPA5623 schematic Panasonic needed

That's what happens when it's 3am and you "quickly " want to replace the chip still lol.
Solder iron was set at too low of temp, I flooded the pins with solder and normally it just flips off the board with a little shove from the iron.
It not being not hot enough and me sleepy I pushed a little to hard and did damage. Then I realized it was to cold and cranked up the iron. Made it too hot while trying to clean with solder wick and then I gave up haha.
Don't do this small stuff late at night. I'm not proud of this screw up at all.

[tom66]

Re: TNPA5623 schematic Panasonic needed

The centre pad is essential for cooling.
That is pretty bad, I am not sure you can repair that.
How did you try to remove the chip? If the chip is stuck, do not pull!! It will come off with surface tension on a river of solder by flooding both ends in turn.