50mf231d/37 Power supply repair

[RCA2000]

Re: 50mf231d/37 Power supply repair

I am back...after a long accidental absence. I WILL be here ..on a very regular basis. love to help other people fix stuff. Been in my blood for over 30 years now...been a career about that long too. But I am not PERFECT...I make mistakes too.

NOW...I ALSO collect the OLD electronic stuff..particularly TV sets older than 1990--and mostly 1980...ALL tube audio stuff, old amps, silver-faced stereo receivers, and radios and such.

[kca]

Re: 50mf231d/37 Power supply repair

Great! Thanks for your help, RCA2000.

I thought I would try to utilize this suggestion from a poster back in 2015 that read as though it would likely help to ensure the through-hole connectivity we are seeking:

Maybe try some silver flux, heat capacitor lead wire about 1/4 inch down leave lump of solder on wire leads then insert capacitor, from underside of board (capacitor facing up) heat lead wires and solder will drop from top down. Let cool then flip board over and solder feet in, then check with multimeter. Hope you get it done. Good Luck

Do you have any thoughts on that? I am not sure about the silver flux part. Do you think he means to coat the cap lead with this? Is that necessary, or could I just heat up the cap lead a bit and leave the lump of solder to flow down the cap lead leg as I insert it?

Do you happen to be subscribed to this thread, RCA2000? I would really like to be able to write to you again for advice if I have any other questions that arise before my new caps arrive in the mail, and perhaps as I am doing the actual repair if things start to go awry in any way. You have been extremely helpful and I appreciate your expertise. I've only been doing this for a couple of weeks now, but learning rapidly thanks to folks like you.

[kca]

Re: 50mf231d/37 Power supply repair

Sorry, RCA2000.

I didn't mean to post that same message again on this thread.


I'm glad your long absence is over and you're back!


~ kca

[RCA2000]

Re: 50mf231d/37 Power supply repair

No problem...we ALL make mistakes..ESPECIALLY ME !!

Just recently...I had a PS from an LG PDP set...I looked at..it was doing the "click...click..click" thing. Run voltages absent... stby voltage came up and dropped. Just ONE bad Poly flim cap on the run supply. I took it with me to here to rebuild it. To test it..I put in a cap I had on HAND..rated a bit LOWER in voltage (1000 vs1250) than the old one...JUST to insure it would fix it. But when I hooked my hot cord to the PS to test it. ...I ACCIDENTALLY hooked it ACROSS the main ac fuse connection. Needless to say...this did NOT work too well !! Only damage was that fuse.. which I replaced temporally with another--till I got a new proper one. put my test cap and fuse in. Lit it off and ALL was ok. VS, VA and other volts fine, and HOLDING. I did NOT let it run for more than a few seconds this way. I ordered a new 22N/1250V. pilkon cap and 10A fuse and completed repair. Set works fine now.

SO a mistake is fine...we ALL do it..especially ME. BLAMING someone ELSE for your OWN mistake---or covering it UP...THAT is where things can get UGLY !!!

[kca]

Re: 50mf231d/37 Power supply repair

Hello again, RCA2000 ~


Given all of the good advice that you, and others, have given, here is my plan of attack for the repair. Please let me know if you think it's good in total, or if it is flawed in any way:

I am going to leave both of the through-hole positives alone and just solder in the new cap leads there per usual as they both show very clear through-hole, or via, conductivity.


On the C8059 negative, I will scrape the top (being sure to stay within the light green track as I do), and solder the strand wire to the top of the board as you've suggested. Then, drop that through the hole and just solder the strand and the cap lead together on the bottom of the board without any further scraping on the bottom of the board.

On the C8060 negative, I will scrape the top (staying in its light green track), and solder that strand wire to the top of the board as you've suggested. Then, drop that strand wire through the hole. I will then put that cap lead through and cut it down to about 1/2 inch. I'll slip the circular ring pad I saved over this cap lead (and the strand wire too, if possible) and fit that pad down into the burned area so it fits as tight there as possible. I will carefully scrape the area of dark green just to the left and slightly up from the C8060 hole here on the bottom of the board (about the 10 o'clock position), and then bend both the cap lead and the strand wire onto this scraped area and then solder them there. I'll finish by making sure the total amount of solder here on the bottom of C8060 negative covers everything related to the fix (meaning, the solder will form over the cap lead and strand wire where they come out of the hole at the and through the replaced ring pad, and that the solder also flows all the way over to the newly scraped area in the 10 o'clock position so that it is one, continuous "river" of solder in that area).


Does that make sense as an overall approach?


Note: I am also going to try to flow as much solder down into the through holes during the fix as possible, to help ensure that those via conductivities are as effective as possible. I am going to do this by fluxing the cap leads and then trying to drip a drop of solder down into the through-hole by following the advice of this former post:

Maybe try some silver flux, heat capacitor lead wire about 1/4 inch down leave lump of solder on wire leads then insert capacitor, from underside of board (capacitor facing up) heat lead wires and solder will drop from top down. Let cool then flip board over and solder feet in, then check with multimeter. Hope you get it done. Good Luck

[ljintexas]

Re: 50mf231d/37 Power supply repair

If you need it, I have an smps out of that exact model tv that was rebuilt and tested. Panel wound up being bad..I have all of the boards from that set.
PM me if you are interested.

Thanks

[kca]

Philips 50" plasma - 50PF7220A/37

Hello again RCA2000 and others ~

I am still working on the repair of my Philips 50PF7220A/37 50"plasma television.

I just started this as a new thread, but wanted to cut and paste it here as well. If you have time, please look it over and tell me what you think I should do or test next:


Hello all ~

I have already replaced the two swollen caps (C8059 and C8060) on this, and am still getting the red light that blinks 7 times on the front (repeating) and on the power supply itself I am still getting the green light blinking 4 times (repeating).

Does anyone know what this combination indicates, or how I can look that up for myself? Error code information (especially for the green blinking sequence on the PSU itself) and the service manuals for this tv set seem hard to come by.

Other information:
When plugged in each and every time, there are two green lights that light up at the bottom center of the power supply unit. They are accompanied by two clicking sounds. One comes on a moment before the other, but then both turn off within two seconds as the power supply shuts down. While this is happening, a small green light on the logic board (the board that sits underneath the power supply) lights for about 1 second and then shuts off.
Just afterward, I get the separate "4 times repeating blinking green light" that I mentioned in the above paragraph. This one is on the underside of a small board that juts out perpendicularly from the PSU itself, and it located in the upper left hand corner of the PSU.
___________________

At this point, I can't tell if my YSUS board is damaged, and if this is shutting down the PSU, or if the logic board is damaged, or if the PSU is faulty in and of itself.

I have tried disconnecting the YSUS and the XSUS cables, one at a time and separately, with no change in the result. I also tried to disconnect the logic board cable from the PSU and here the green blinking code on the PSU itself changed from 4 times (repeating) to 13 times (repeating). That seems to indicate that the logic board may be good because one would think that if it were bad I would get the 13 times (repeating) blinking green light on the PSU whether the logic board was connected or not to the PSU.

The 7 red light / 4 green light blink combination was the same both before and after I replaced the two capacitors mentioned above.

Where do I go from here?

[RCA2000]

Re: 50mf231d/37 Power supply repair

Ok...are you getting ANY decent run voltages fomr the PSU? Such as the VA and VS lines--do they even try to rise to normal valus?( Ballpark--180-210 for VS 45-65 VA)

keep in mind...just because the OTHER caps do not LOOK bad...they STILL can be JUST as bad..a.s the others were. On that LG I replaced the Poly cap --it was NOT cracked and barely noticeably swollen at ALL. But it was TOTALLY bad.

ALSO...I would OHM the PS lines to cold ground--and see if there are any abnormal loads showing.

If it gets TOO hairy..perhaps you SHOULD look into another PS board...Even I have to do that sometimes...

[kca]

Re: 50mf231d/37 Power supply repair

I tried to measure some of the voltages, but it was difficult because the protection mode kicks in so quickly (less than 2 or 3 seconds). I was fearful of plugging and unplugging the tv in too many times in order to get the reads you requested. I can try again, if you'd like, and target certain ones if you help me to identify the most important connectors and pins.

Before we do that, however, I have found something I think may be of great interest. The connector labeled 1M46 in the lower left corner of the PSU was the only one that had any effect on the 7 blinking red/4blinking green combo I described earlier. When this connector is pulled, the 7 red blinking lights stopped blinking completely (but the 4 green blinking lights on the PSU continued). This appears to match up with some other posts that identified the 8V6 as the most likely issue. I'm hoping you can tell me if this makes sense as an area of focus, and what, exactly, 8V6 means.

The photos I have posted show the 1M46 connector (after I pulled it), and a chart from an online source that helps to confirm that the 7 blink code is related to the 8V6 issue.

Thanks for all of your help, RCA2000, and anyone else who may wish to contribute.

[kca]

Philips 50" plasma - 50PF7220A/37 (Service Manual)

By the way, I just found what I am pretty sure is the correct service manual for this model.

I did it by Googling the Chassis # on Manualslib.com

My particular Chassis # is BP2.3U AA. Even though the link below only reads Bp2-2u, you'll see if you click it that it takes you to a manual that covers the BP2.2U and the BP2.3U models.


http://www.manualslib.com/manual/835...2u.html#manual


Hope that may help someone else.

[kca]

Philips 50" plasma - 50PF7220A/37

I should have mentioned, also, that the following is true re: the CN1M46 connector:


If the CN1M46 was pulled before I plugged in the AC, it would not matter if any or all of the remaining connectors on the PSU were in or not. If that CN1M46 was pulled out before the AC was applied, there would be no blinking lights on the front of the tv. The 4 green on the PSU itself would be there (is this called the "daughterboard"), ..... but no red up front. The 7 blinking reds up front only returns when I plugged the CN1M46 connector back in.


Note: The only exception to this is the 10-pin connector that comes straight off the bottom center of the PSU (CN8006) and goes down to CN2026 on what I think is the logic board. If that was pulled, then I would get the 13 blinking green lights on the PSU (daughterboard) and a previously unseen 1 long red followed by 4 short reds on the front LED. With that connector back in, this combination disappears. So, it seems to indicate that if the power supply could stay up and at normal levels, the logic board is indeed in tact.

[kca]

Philips 50" plasma - 50PF7220A/37

Don't know why my pictures from a couple of posts ago loaded and attached upside down, so I reversed the original image and am trying it again.

[RCA2000]

Re: 50mf231d/37 Power supply repair

Anyone here know if this PSU can be "free run" AWAY from the set--with NO ill effects? I know Sam and LG PSU'S usually can and I think Pana ...but not sure about Phillips.

[kca]

50" Philips Plasma ~ 50PF7220A/37 ~ PSU markings

Not sure if this helps regarding RCA2000's last post/query, but the attached pic indicates Samsung design.

Also, the # on this PSU board is:

LJ44-00108C PS-504-PH

and to the right of that it reads:

Rev0.7 20051107

[kca]

Philips 50" plasma - 50PF7220A/37 - CN1M46 focus

This morning, I decided to focus my diagnostic testing on the CN1M46. Here are the results, with my readings taken from the copper test areas that exist just to the left of the connector itself and allow for easier testing access (please refer to the attached image):


12v = Rises to 11.9 then falls rather quickly (within 3 seconds of the PSU shutting down

N.C = Did not test
12v = Did not test

Vtun = Rises to 78.5 and then begins to slowly fall toward 0.00. It would probably take almost a minute for it to fall all the way to 0.00 if I were to leave the probe there. Interestingly, it would start wherever it left off. Meaning, if I let it drain to say, 55.0, and then removed the probe and then replaced it, it would pick up its descent at 55.0 and continue to fall. Even more interestingly, this would happen even if I pulled the AC plug out of the set.

5v2 = Rises to 5.1 and stays there. It appears that it would stay at 5.1 indefinitely as I held the probe there for over 30 seconds without any change.

GND

5V_sw = Rises to 5.1, then stays there without change for about 7 seconds. Then it falls to 0.5 and then from there it slowly falls to 0.00 over the course of about 10 seconds.

12v = Did not test

8v6 = Quickly rises to 8.4 and then quickly drops (within 2 seconds) down to 0.00

GND
GND

[kca]

Philips 50" plasma - 50PF7220A/37

Given all of the above information, are there any tests or actions I can take to continue in a forward manner at this juncture?

I am determined to figure out what is causing this PSU to shut down almost immediately after the AC is applied each and every time. Seems like if I can get beyond this sticking point, the entire set may fire up and work as expected.

A related question is:
Could the bad caps I replaced (C8059 and C8060) still be responsible for the shutdown, in concert in some way with the CN1M46 connector .... assuming I did not complete the capacitor fix in a proper manner? I'm concerned about this because my desoldering job caused the through-hole connectivity to be a bit suspect. I think I fixed it before putting in the new caps, but I am not sure. If not the C8059 and/or C8060, could other bad caps be causing the CN1M46 to be problematic and to be putting out the readings it is?

Just trying to make some logical connections or eliminate things I do not need to be placing focus upon.

Thanks

[kca]

Philips 50" plasma - 50PF7220A/37 - D3V3 issue identified

Hello RCA2000 and All ~

I gained some more insight in the last couple of days.

First off, the Vs and Va voltages are not coming up on the PS, due probably to the power shutting down so quickly and before it reaches the XSUS YSUS and/or buffer connectors.

XSUS connector VS reads 0.46 only and then slowly drops to 0.00 (over the course of 3 minutes or so)

YSUS connector VS only rises to 0.06

Va on the buffer connector does not rise either

Importantly, I have now figured out what the 4 green blinking light sequence on the PSU itself means. Kicking myself a bit because there was a key right underneath it that looked like it was related to connector pins but it actually is the Alarm Signal Key for this flashing light. 4 flashing lights here means D3V3. I think that is related to the Main Board SSB (small signal board) as much of my research has seemingly connected the two.

Here is what I think is happening, and I would love to have some feedback that either confirms or denies this.

1) The PSU is shutting down and going into protection mode because the Main Board SSB is faulty.

2) I am getting the short-lived green lights on the PSU and on the Logic Board because the voltage begins to flow properly through the initial stage of the PSU and into the Logic Board, but when it hits the Main Board SSB it fails and then shuts everything back down.

Given all of this and the information I have posted in this thread earlier, does it make sense that it is probably a faulty Main Board? If so, can the SSB be replaced without replacing the entire Main Board Unit (housed within the large silver box)? It seems like it can, but then I apparently have to reset a new SSB with an Option Code which is usually found on a sticker inside the tv or on the back of the chassis. Problem here is, this sticker does not exist on my television. I've looked everywhere.

If anyone knows where I can find a listing of Philips Option Codes and, more particularly, for the 50PF7220A/37 itself, I would be grateful. This sticker also supposedly has a three-digit Diversity Code, which may or may not be completely unique to my tv.

A related question is, I have found the exact same Main Board unit for sale ($89), and the great advantage with this one is that it has the exact same numbers as the sticker on the back of my Main Board. It's the only one of dozens and dozens I've looked at that has this exact sequence of Part Numbers:

S 3104 328 38116
SW 3104 337 00841
OPT 3104 309 27641

I know that I can put other, compatible SSB's in or even an entire Main Board with a compatible SSB having a different Part #, but the problem there is that without the sticker that has the Option Code and Diversity Code, I will ultimately have no way of reconfiguring a compatible SSB in the correct manner.

I am hoping to get that info so I can buy a SSB for under $40, but I will entertain the idea of spending the $89 plus shipping if someone here knows that by doing so I can skip the reconfiguring SSB step because the Part Numbers are an exact match.

I know that's a lot of information, but I am hoping RCA2000 or someone else can provide some insight on any or all of these points.

[ljintexas]

Re: 50mf231d/37 Power supply repair

Not even the same series...I have Ysus, Xsus, main cpu, SSB, SMPS and buffers.