Philips 50" Plasma 50PF7220A/37 - Progress and Update

[kca]

Hello all ~

Here is my situation as of a couple days ago:
When AC is applied, two small green lights (8001 and 8002) come on briefly at the bottom of the PSU. The green light on the logic board lights up briefly. Relays click twice and then the whole thing shuts down. All of this happens in less than 5 seconds of the tv being plugged in and the AC applied.

Also, a green light up in the upper left-hand corner of the PSU begins to blink 4 times (repeatedly), and the front panel LED green light comes on momentarily before going into a 7 red blinking (repeatedly) protection mode.


UPDATE:
I've now 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 at a glance 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 the majority 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. The DV3V voltage is therefore not being processed properly by the broken SSB, and the PS shuts down in response.

2) I am getting the two short-lived green lights on the bottom of the PSU (8001 and 8002) 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 on a separate thread (you can search for 50mf231d/37 Power supply repair and go to Post #27), ....

does it make sense that it is probably a faulty Main Board? If so, can the SSB be replaced as a single board 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 someone can provide some insight on any or all of these points. Thanks in advance for any replies/advice.

[ZnsaneRyder]

Re: Philips 50" Plasma 50PF7220A/37 - Progress and Update

Does your power supply have green and black SAMXON capacitors on it?

If so, I would change ALL the green ones, and most or all of the black ones. A Phillips Plasma TV will shut down if the caps are not good, and make it seem like other things, blinking and all.

If they are SAMXON GF or similar green or black, they don't have to be swollen to need changing. Change them anyway. They are that bad.

Once the capacitors are changed on the power supply, and the TV still does not work, then I would worry about the main board.

[ZnsaneRyder]

Re: Philips 50" Plasma 50PF7220A/37 - Progress and Update

I just found an image of your power supply, it's not the same as the 50 inch one I fixed, but it is similar, and it does have samxon caps, so change ALL the small ones, and you can leave the four HV large ones.

[kca]

Re: Philips 50" Plasma 50PF7220A/37 - Progress and Update

Thank you, Z ~
I was wondering if bad caps might actually be the root of the problem. They all look good, but as you said they are still likely to be malfunctioning due to the poor quality of the original product. My soldering skills are still a bit suspect, but I am willing to give this a shot if you really think the 7 red / 4 green blink combination is directly related to a bad cap or caps.

The other thing, then, that might be going on is the way in which I ended up soldering in the two caps I have already replaced (those being C8059 and C8060). In a nutshell, after burning two of the four pads out more that is desirable when desoldering, I still had enough proof of through-hole connectivity to go ahead and repair the situation and replace them with Rubycon ZL's.

One capacitor sits tight to the top board and is soldered on the bottom in a way that I am confident about.

The other, however, is now resting just slightly above the top board because when I passed a through-wire through the via to help ensure conductivity from top to bottom (I twisted together about 5 strands of speaker wire for this), I ended up leaving it looped once around the capacitor lead and it is just there without currently being soldered to the board in any way.

Could this be the cause of the continuation of the 7 blinking red / 4 green sequence I've described? Might make sense if it is, because those are the same symptoms/indicators I got when I first brought this tv into the house and discovered the two bulging caps when I opened it up.

An important related question then is, is there a way I can test the SSB/Main to see if it is indeed functioning properly. I'll go back and attack the caps with much more confidence if I know the SSB/Main is actually okay. I currently have the entire silver box with SSB still inside taken off the back of the tv. Some of the security screws stripped so I am still trying to get inside. But, if there is a reliable way to test it without getting inside, I'll do that first.

Thanks for your insight. I am determined to get this set up and running, and enjoy learning along the way.

[kca]

Re: Philips 50" Plasma 50PF7220A/37 - Progress and Update

Wondering if ZnsaneRyder or anyone else has some thoughts on the last post I made here (#4) a few days ago?

I just finished up fixing a Hitachi P50H401 plasma, and am now ready to tackle and to attack this Philips 50" Plasma 50PF7220A/37 again.

Thanks for any insight(s) that can be provided re: the PSU vs. SSB Main as the two most likely suspects on this particular television set. Any way to test these beyond the obvious voltage tests? Those are hard to complete as it keeps shutting down only 2 seconds after it powers up.

I am also wondering if anyone knows if the SSB and/or Logic Board can shut down as a result of a bad YSUS or Y-buffer boards on this model, and if that would make sense considering the D3V3 troubleshooting/protection light (4 flashing + green on the PSU itself) that still appears every time I attempt to turn it on.

Any help would be greatly appreciated.

Thanks in advance for your replies.

~ kca

[kca]

Re: Philips 50" Plasma 50PF7220A/37 - Progress and Update

Posting some new information here today and asking for help.

I have not replaced any more caps yet on this PSU. Just the C8059 and C8060 from a few weeks ago. Still getting the 7 red blinks on front LED and 4 green blinks on the PSU itself (which is the DV3V code). Standby power is failing, apparently, and I've narrowed it down to three possibilities:

1) The caps on the PSU (C8059, 8060, and/or others) are faulty.
2) The logic board is not processing the DV3V voltage properly.
or
3) The SSB is faulty and prohibiting the set from powering up.

My question is:
If all of my essential initial voltages (meaning DV3V, DV5, 8V6, and all the others one might suspect) BEGIN TO RISE, but then never quite reach the levels they ought to be before rapidly falling off when the unit shuts itself down (about 2 to 3 seconds into it), is this more likely due to bad caps on the PSU or to a faulty Logic Board or a faulty SSB/Main?

The key fact that leads me to think that it is NOT the PSU is that if I disconnect the C8006 connector from the bottom of the PSU that leads directly into the Logic Board, I no longer get the 4 green blinks on the PSU but I get 13 instead. And, whereas 4 green blinks indicates a DV3V problem, 13 green blinks indicates a DV5 issue. So, my reasoning is that the PSU is indeed attempting to generate the correct and necessary standby voltage (DV3V), but it cannot sustain it because the Logic Board or SSB fails to do its work. I would think if it were bad caps on the PSU that were the root cause of the problem, then I would get 4 green blinks on the PSU whether or not the connection to the Logic Board is made through this C8006 connector. Does that make sense?

This, combined with the fact that the 7 red blinks on the front of the set appear to indicate an 8V6 problem (see attached pic), I am thinking that the problem lies within the SSB/Main unit because the PSU connects to the SSB/Main through connector 1M46 (see other pic) and that is the only connector that has the 8V6 labeling on it.

If I try to replace all the small caps (about a dozen) on this PSU, I feel like I am likely to do more damage than good. They are difficult to desolder correctly as it is a double-sided board with through-hole connectivity being imperative.

The DV3V voltage only rises to 2.2, and no higher. This seems to be the crux of the problem as the 4 green flashing LED light on the PSU itself indicates exactly the same according to its Alarm Code labeling (i.e., DV3V). I have run a lot of voltage tests on every connector, and can provide those numbers in response to anyone who replies and wants to know how those look.

[kca]

Re: Philips 50" Plasma 50PF7220A/37 - Progress and Update

More proof that the PSU (Power Supply Unit) is not the issue, or at least the primary issue:

Extensive testing using the DV3V test pin found under the capacitor labeled C8059 (see pic attached below) on the PSU revealed the following:

1. D3V3 voltage rises to 3.3v if the Logic Board is disconnected from the PSU.

2. D3V3 voltage rises to ONLY 2.2v if the Logic Board is connected back again to the PSU.

3. DV3V voltage rises to ONLY 2.2v if the Logic Board is connected to the PSU, and the Logic Board is disconnected from the SSB/Main.

This appears to indicate that the Logic Board may be faulty. Or, ... because I am getting 7 red blinks on the front LED (indicating an 8V6 error), it may simply be that the SSB needs to be replaced (see my previous post for more pertinent info here.) before the D3V3 voltages will process properly within the structure of the Logic Board.

So, my plan is to do the following:

First, replace the SSB only and see if that resolves all of the issues.

Second, if the new SSB fixes the 8v6 problem (i.e., no more 7 blinks), but the DV3V problem persists (as probably then indicated by 11 flashing red lights on the front panel of the set (see Error Code pic again), then I may have to replace the Logic Board as well.

After that, I will return to the idea that one or more caps might be bad in the PSU. Or, follow in the direction that any new error code information reveals to me.


So, all Badcappers.net Agents of Advice and Wisdom out there ....

Does this sound like the best and most logical plan of action?