Panasonic plasma TC-P42G25 one LED blink, no power

[rockola1454]

Hi,

I was watching my Panasonic TC-P42G25 plasma two nights ago, and when i turned it off I heard a snap. Trying to turn it on since then results in the LED blinking once, and no picture.

I have electronics repair experience, but have little with flat panel TV's in particular. I left it unplugged for a day, to ensure the same LED one-blink. I found the service manual online, in which it maps one blink to a) Unknown SOS, b) Panel Information SOS, or c) PD4 Start SOS. This doesn't tell me much.

Googling around, I haven't found much on the single-blink code for my model. I pulled the power, "A" and "SS" boards to inspect them top & bottom. I checked for the following but everything looks good, I didn't see any:

- cracked or shorted transistors
- low value resistors that are open
- caps that have vented/bowed up
- bad fuses in power board
- any obvious/burnt signs of damage

I also looked at the SC board but didn't notice anything odd there.

More Googling, and I did find mention of checking for voltages on 4 test points: VSUS, VDA, VAD, VE. All four stay at 0 volts while I try to power on the set, and while the LED does its single blink. I find this interesting, since there has to be voltage somewhere powering the diagnosis circuit that blinks the LED.

I'm a bit stuck now. Any advice what I should test/inspect/kick next? I've seen several people mention 1 blink can point to the A board, although the service manual for my set doesnt mention this; rather it suggests A board issues are 2,3,5 & 9 blinks.

Are there any detailed guides on how to troubleshoot an A board for component failure? I'm worried just buying a replacement or repair for my A board either won't work or will just be killed again if something else is defective.

Appreciate any help. Thanks!
-Chris

[Alastair E]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

I seem to remember, SOS 1 ( 1 blink) implies the main 5V rail not present to mainboard.....

[tw2005]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

generally 1 blink is A board. hearing a snap seems to suggest the SC board may have failed too. Try disconnecting SC2, ss11, p35, 3 white ribbons at the A board and power up and see if still one blink.

Don't reconnect those for 5 mins to let the residual voltage drop off. None of the voltages you mentioned have anything to do with the A board being able to run and diagnose the SOS.

Also check Sc2 across those for resistance and see if shorted. may be unlucky and have 2 faults. Sudden shutdown may have corrupted eeprom

[rockola1454]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

Thanks, guys! Here's what I found:

>> Try disconnecting SC2, ss11, p35, 3 white ribbons at the A board and power up and see if still one blink.

I did this, and the power led stays on! Obviously no picture, but there is no blink. The set seems to "think" it is fine, powering the led on/off with the power button. What does that indicate?



>> Also check Sc2 across those for resistance and see if shorted

Across the two pins of SC2 plug on the SC board, I'm not seeing that shorted. No short on the power board end of that plug, either.



>> I seem to remember, SOS 1 ( 1 blink) implies the main 5V rail not present to mainboard.....

Not sure which is the 5 volt rail to board A, but the 2 plugs that run from P to A (A6 & A7) have some test points near the plugs, can those readings help?

TP . . . . . . . Off . . . . Pressing Btn
-----------------------------------------------------
TP3522 . . . . . 5v . . . . . 5v
TP3526 . . . . . 0 . . . . . (15v real quick then back to 0)
TP9200 . . . . . 0 . . . . . (15v real quick then back to 0)
TP3520 . . . . . 0 . . . . . 0

[tw2005]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

Thanks, guys! Here's what I found:

>> Try disconnecting SC2, ss11, p35, 3 white ribbons at the A board and power up and see if still one blink.

I did this, and the power led stays on! Obviously no picture, but there is no blink. The set seems to "think" it is fine, powering the led on/off with the power button. What does that indicate?



>> Also check Sc2 across those for resistance and see if shorted

Across the two pins of SC2 plug on the SC board, I'm not seeing that shorted. No short on the power board end of that plug, either.



>> I seem to remember, SOS 1 ( 1 blink) implies the main 5V rail not present to mainboard.....

Not sure which is the 5 volt rail to board A, but the 2 plugs that run from P to A (A6 & A7) have some test points near the plugs, can those readings help?

TP . . . . . . . Off . . . . Pressing Btn
-----------------------------------------------------
TP3522 . . . . . 5v . . . . . 5v
TP3526 . . . . . 0 . . . . . (15v real quick then back to 0)
TP9200 . . . . . 0 . . . . . (15v real quick then back to 0)
TP3520 . . . . . 0 . . . . . 0

locate Q661 on the SC board, smallest heatsink, check if shorted

[tw2005]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

with the LED no blink, The Tv was on as in out of standby, does the led blink during stratup and then lock solid as it's normal sequence. We have Red stdby/green running on ours

[tw2005]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

have you got manuals to follow?

[Moreno83]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

I fixed a Panasonic 1 blink error with replacing the main board! It was doing exactly the same as yours ( dropping the 15V real quick ).

Hope it helps

[rockola1454]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

Hi All,

>> locate Q661 on the SC board, smallest heatsink, check if shorted

Wow, you zoomed right in on it! Once I removed the SC board and tested the heatsinked IC's, I found 11 shorts! Each desoldered just to be sure:

Q661; Q660; D422; Q422; Q421; D402; D401; Q403; Q402; Q452; D482

>> does the led blink during stratup and then lock solid as it's normal sequence. We have Red stdby/green running on ours

Yes, mine only seems to have a red LED, I've never noticed green. Normally when i hit power on the remote, the red LED turns on and stays solid while the set warms up a couple seconds.


>> have you got manuals to follow?

I was able to find the service manual for my model, although it doesnt seem to give great ideas on how to narrow the problem down


So, with all of these IC's shorted on the SC board, is there a way to know if there is other damage as a result? Or, if i buy replacements for these shorted parts, should it just come back to life?

[tw2005]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

Hi All,

>> locate Q661 on the SC board, smallest heatsink, check if shorted

Wow, you zoomed right in on it! Once I removed the SC board and tested the heatsinked IC's, I found 11 shorts! Each desoldered just to be sure:

Q661; Q660; D422; Q422; Q421; D402; D401; Q403; Q402; Q452; D482

>> does the led blink during stratup and then lock solid as it's normal sequence. We have Red stdby/green running on ours

Yes, mine only seems to have a red LED, I've never noticed green. Normally when i hit power on the remote, the red LED turns on and stays solid while the set warms up a couple seconds.


>> have you got manuals to follow?

I was able to find the service manual for my model, although it doesnt seem to give great ideas on how to narrow the problem down


So, with all of these IC's shorted on the SC board, is there a way to know if there is other damage as a result? Or, if i buy replacements for these shorted parts, should it just come back to life?

Ok, so what i want to be 100% sure is you are confident the TV came out of standby and was on with no blinks. If you have a meter to measure just over 200V dc you could back probe the p2 connector for Vsus. I know it seems like I may being silly asking this but the last thing i want to see is you replace the SC and the 1 blink was till there because then you'd need an A board.

i have tried putting the SC board on the ground and performed an ancient ritual appealing to the gods but , alas, it could not be revived.

It will require human intervention by you or ModuslinkPTS.

What skills and equipment do you have? Since you have a fluke I'm thinking you've got prior experience? Will involve smd work , not too hard but i can link you to my thread or search yourself.

just take your time and we can get this right first go, don't go off in tangents and jumping the gun powering this up. far easier getting first time around it right.

[tw2005]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

Thanks for the list, none of these are ICs, IGBTs, FETs and diodes, a good start for me to get a feel of what is most likely DEAD as they are only part of it(80%) the balance is what's important as if it's missed you kill all those again, mostly.

I'm not familiar with the 42", confirm what I put up if correct or not, only matters if you are ordering the parts.

YES = normally blown or I've seen ( history of 5 boards)
NO = opposite to yes (LOL)

Q661; RJP63F3A , IGBT, YES

Q660; R5007ANX , 500V 5A , FET, NO(this is one I've read also RJK6026? 600v 5A fet) not normally one that is shorted

D422; RFUS20T4S, DIODE NO

Q422; DG402RP , IGBT,YES

Q421; DG402RP, IGBT, YES

D402; DA3DF50 , DIODE, NO

D401; DA3DF50 , DIODE , NO

Q403; DG502LW, IGBT, YES

Q402; DG502LW , IGBT,YES

Q452; 45G128 , IGBT,YES

D482 RFN25TM4SW , DIODE, YES

Now for the things possibly missed and definitely missed.


IC16521 M81737FP, FET DRIVER shortedd, blown,burnt low resistance on P15V rail , generally just replace it

IC16773 TC7SH14F, schmitt inverter ic (can use SN74AHC1G14DBVTG4) ALWAYS shorted

Q702 2PD601ART NXP (C3 W), AFAIK ALWAYS(shorted)

Q621,622 GT30F125(R) ALWAYS I FIND( shorted or low ohms got 0.190 in diode, normally around 0.9 -1.00 in cct) Sometimes the other is ok. catches people out

D451 400V 1A diode, RF071L4S, or RF101L4S , USUALLY LOOKING AT THE OTHER PARTS FAILED NEARBY. (shorted)

Both these generally can be ok, I now just replace regardless, takes the risk of a mistake out.

Q701 MMBTA92 seemed ok but replaced
Q818 2SK3018 also not shorted but replaced

Watch out for

shorted D702 but some resistance checks I know will verify if all is well.
bad 5v reg IC771, it powers IC773 and other stuff

ic724 %v REG FOR THE BUFFERS, if that's bad, expect shorted buffer board/s

opto PC461, rare but does go.

I think there maybe a few 42" boards for sale, repair by moduslinkpts may be just as cheap or cheaper,

[tw2005]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

Oh, hope you have not thrown any parts out, don't! I think you may have tested some of these incorrectly particularly the diodes.

[rockola1454]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

>> ...you are confident the TV came out of standby and was on with no blinks. If you have a meter to measure just over 200V dc you could back probe the p2 connector for Vsus.

Yup! I tested once more, and again the power button seems to work normally, LED blink is gone. This time I probed P2 and see 210 volts. Is it unusual that my set gave me the one-blink for an SC board fault instead of say 6 or 10 blinks per the svc manual?


Here is what I found on the parts:

Confirmed Part#
======================
Q661; RJP63F3A, IGBT, YES
Q422; DG402RP, IGBT, YES
Q421; DG402RP, IGBT, YES
Q403; DG502LW, IGBT, YES
Q402; DG502LW, IGBT, YES
Q452; 45G128, IGBT, YES
D482 RFN25TM4SW , DIODE, YES
D422; RFUS20T4S, DIODE NO
*** I tested wrong - pins 1 & 3 connect b/c it is a diode
D402; DA3DF50 , DIODE, NO
*** I tested wrong - pins 1 & 3 connect b/c it is a diode
D401; DA3DF50 , DIODE , NO
*** I tested wrong - pins 1 & 3 connect b/c it is a diode


Alternate Part#
======================
Q660; --> RJK6026 600v 5A fet -- not normally one that is shorted
*** It is 2.5 Ohms b/t pin 2 & 3; I assumed that was low enough to be bad, is it normal?


Missed Parts
======================
Q702 2PD601ART NXP (C3 W), AFAIK ALWAYS(shorted)
*** This is 73 ohms b/t pin 2 & 3
Q621,622 GT30F125(R) ALWAYS I FIND (shorted or low ohms got 0.190 in diode, normally around 0.9 -1.00 in cct) Sometimes the other is ok. catches people out
*** These are around 200 ohm b/t pin 1 & 3 (still soldered in place)
D451 400V 1A diode, RF071L4S, or RF101L4S , USUALLY LOOKING AT THE OTHER PARTS FAILED NEARBY. (shorted)
*** This is 150 ohms
*** Looking nearby, Q521 & Q551 both show 0 ohms b/t pin 1 & 3 on the 3-pin side...
IC771; bad 5v reg (powers IC773 and other stuff)
*** This is 5 ohms b/t pin 1 & 2


*** Not sure how to test these, I'll assume they're bad
IC16521 M81737FP, FET DRIVER shortedd, blown,burnt low resistance on P15V rail , generally just replace it
IC16773 TC7SH14F, schmitt inverter ic (can use SN74AHC1G14DBVTG4) ALWAYS shorted
PC461; opto, rare but does go.


*** Seem ok, but I'm all for reducing risk
Q701 MMBTA92
Q818 2SK3018


D702 Watch out for short but some resistance checks I know will verify if all is well
*** This is 4KOhms, I assume it is ok...

IC724 %v REG FOR THE BUFFERS, if that's bad, expect shorted buffer board/s
*** Not seeing any short in this one...


>> I think there maybe a few 42" boards for sale, repair by moduslinkpts may be just as cheap or cheaper

Next I'll look around at how much the total for the parts would be. I guess if the sum of parts > ModusLink, I might as well go with ModusLink

Thanks so much for all your help!! Let me know if there is anything else you think I should check, or if you suspect any other board besides the SC board in my set.

[tw2005]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

This is going to be a big thread isn't it. I'm about to do another 5081 50" board i received today Seeing some subtle differences, I'm not in a hurry.

have you read my TNPA5081 repair?

The parts will be cheaper from china, quicker if local, can get these OEM from sears, encompass, partsimple etc. there are some kits but they're marked up well. There are some parts individually sold in the US ebay. hard to tell if they're any better and can't be sure the photos are of actual items.

It is unusual for a 1 blink but with shorts on power lines who knows. I have had a short from bad SS, did the usual 4 blink, it's another saga but you could check my profile and look for th-P42x20. basically i did not discover the 1 blink until the end, so just as the panel was about to initialise it one blinked. pissed me off. But the test you've done clears that issue


Q621,622 GT30F125(R) ALWAYS I FIND (shorted or low ohms got 0.190 in diode, normally around 0.9 -1.00 in cct) Sometimes the other is ok. catches people out
*** These are around 200 ohm b/t pin 1 & 3 (still soldered in place)

Better pull these, i think this is where some repairs have failed.

47K on a good board, I have bad board here 188, 203 ohms

Also, do me a favour, which is pin 1,2 & 3? left to right, right to left, as per a datasheet or what?

The board has G,C,E so I can reference that. I don't feel like digging datasheets to work it out and I'm assuming outer legs.


Q660 , does sound pretty stuffed, definitely 2 ohms not 2 meg? anyway , yeah replace, hope nothing around that is bad as I have not had one like that, onto my 6th board now.

Looking nearby, Q521 & Q551 both show 0 ohms b/t pin 1 & 3 on the 3-pin side.. That's normal, have you the manual and checked the schematic?

If Q452,D482 are shorted, 1st, pull them, then recheck D451, in diode it should conduct one way not the other and I have no reading one way and 1.28 meg the other but I use diode to check. If in doubt just replace it.

Q521,551, measure opposing sided pins, usually 3 meg or so both ends, with the other parts shorted they show short.

Not sure how to test these, I'll assume they're bad
IC16521 M81737FP, FET DRIVER shortedd, blown,burnt low resistance on P15V rail , generally just replace it
IC16773 TC7SH14F, schmitt inverter ic (can use SN74AHC1G14DBVTG4) ALWAYS shorted
PC461; opto, rare but does go.

IC521, I would majority are bad
IC773 definitely just pull it out.

PC461, rare, once you pull the IC773, measure the pins 5-8 on the opto for resistance. At the moment it's probably a few ohms

IC771; bad 5v reg (powers IC773 and other stuff)
*** This is 5 ohms b/t pin 1 & 2

Ok, this is an important ref point. normal 5.8-6.2k.

That is Vout and at this stage shorted IC773, remove IC773 and recheck. resistance must be as I quoted not greatly different.

Near SC20, TP82, measure that to gnd for resistance, reverse probes and give both, 1240 -1380 ohms (15V line)

[rockola1454]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

Hi!

>> have you read my TNPA5081 repair?

I had not; I went back and read through a few of your threads. Great info, and some part numbers in one of them that I didn't think to check! I'll go through and test those to see if I find any other shorts.


>> do me a favour, which is pin 1,2 & 3? left to right, right to left, as per a datasheet or what?

Haha, in my head I cheat and consider (component facing me) pin 1 starting left to right (unless obviously marked). Sorry for the confusion.


>> >> Q621,622 GT30F125(R) ALWAYS I FIND (shorted or low ohms got 0.190 in diode, normally around 0.9 -1.00 in cct) Sometimes the other is ok. catches people out
>> >> *** These are around 200 ohm b/t pin 1 & 3 (still soldered in place)
>> Better pull these, i think this is where some repairs have failed.
>> 47K on a good board, I have bad board here 188, 203 ohms

After desoldering, one is bad -- 190 ohm between pin 1 (G) & pin 3 (E). The other seems fine, but I might as well replace it too, who knows what stress it has been through.


>> Q660 , does sound pretty stuffed, definitely 2 ohms not 2 meg? anyway , yeah replace, hope nothing around that is bad

Yup, 2.5 Ohms between pins 2 (D) & 3 (S). I checked the schematic and tested a few of the components that are near its 3 pins, but didn't notice any shorted diodes/transistors or open resistors. For good measure, I checked the big diodes on my SM board but didn't notice any shorts.


>> Q521,551, measure opposing sided pins, usually 3 meg or so both ends, with the other parts shorted they show short.

These seem fine, but I'll probably replace them anyway since I already have them desoldered


>> IC521, I would majority are bad
>> IC773 definitely just pull it out.

Will do!


>> >> IC771; bad 5v reg (powers IC773 and other stuff)
>> >> *** This is 5 ohms b/t pin 1 & 2
>>Ok, this is an important ref point. normal 5.8-6.2k.
>>That is Vout and at this stage shorted IC773, remove IC773 and recheck. resistance must be as I quoted not greatly different.

Good call! After desoldering IC773, IC771 (still soldered) reads different.
bottom pins 1-2: 5.3 - 5.7 Kohm.
bottom pins 2-3: 650 Ohms. This starts at 0 and creeps up to 650 Ohm, as if it is charging a cap...

>>Near SC20, TP82, measure that to gnd for resistance, reverse probes and give both, 1240 -1380 ohms (15V line)

Ground probe on GND: 2.9 KOhm.
Ground probe on TP82: 1700 Ohms.

[tw2005]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

Just did another board, have a read. Also that 1700ohms seems weird, maybe the meter. Either way just replace the FET driver, just had one where 15v line was a little lower but Q521,515 were shorting (200 ohms) but that was the driver, removed and they were fine.

When you get the parts and install them give me a summary and I'll see if it's covered and then we'll do some resistance checks.

[rockola1454]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

Hi!

Sorry for the delay, was on a trip for 2 weeks (got married )

The parts arrived, and I have soldered everything in place. Below is the list of what all I replaced (and with what).

Do you have some resistance checks I can do to see if everything looks to be in good shape?

LOCN-----Part# (Service Manual)-----Part# (UT Source)
Q402-----DG3D5020CSLW-----DG502LW
Q403-----DG3D5020CSLW-----DG502LW
Q421-----DG3D4020CSRP-----DG402RP
Q422-----DG3D4020CSRP-----DG402RP
Q452-----B1JAEP000012-----45G128
Q521-----B1HFPFA00001-----CPH5524-TL-E
Q551-----B1HFPFA00001-----CPH5524-TL-E
Q660-----B1CERR000042-----RJK6026 (TO-220)
Q661-----B1JAER000010-----RJP63F3A
Q621-----B1JADN000009-----GT30F125
Q622-----B1JADN000009-----GT30F125
Q701-----B1ADCN000007-----MMBTA92
Q702-----B1ABCF000231-----2PD601ART
Q818-----B1CBGD000001-----2SK3018 KN
D451-----B0ECKP000055-----RF101L4S
D482-----B0FACP000003-----RFN25TM4SW
D653-----B0ACCJ000048-----MA2J11100L
D702-----B0ACCJ000048-----MA2J11100L
IC724-----C0CBADE00049-----BA178M05FP-E2
IC771-----C0CBADC00072-----78L05L
IC773-----C0JBAB000715 -----TC7SH14F (HA)
IC521-----C0ZBZ0001708-----M81737FP
IC691-----C0JBAC000363-----TC7SH00FU


Thanks!
-Chris

[tw2005]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

Hi!

Sorry for the delay, was on a trip for 2 weeks (got married )

The parts arrived, and I have soldered everything in place. Below is the list of what all I replaced (and with what).

Do you have some resistance checks I can do to see if everything looks to be in good shape?

LOCN-----Part# (Service Manual)-----Part# (UT Source)
Q402-----DG3D5020CSLW-----DG502LW
Q403-----DG3D5020CSLW-----DG502LW
Q421-----DG3D4020CSRP-----DG402RP
Q422-----DG3D4020CSRP-----DG402RP
Q452-----B1JAEP000012-----45G128
Q521-----B1HFPFA00001-----CPH5524-TL-E
Q551-----B1HFPFA00001-----CPH5524-TL-E
Q660-----B1CERR000042-----RJK6026 (TO-220)
Q661-----B1JAER000010-----RJP63F3A
Q621-----B1JADN000009-----GT30F125
Q622-----B1JADN000009-----GT30F125
Q701-----B1ADCN000007-----MMBTA92
Q702-----B1ABCF000231-----2PD601ART
Q818-----B1CBGD000001-----2SK3018 KN
D451-----B0ECKP000055-----RF101L4S
D482-----B0FACP000003-----RFN25TM4SW
D653-----B0ACCJ000048-----MA2J11100L
D702-----B0ACCJ000048-----MA2J11100L
IC724-----C0CBADE00049-----BA178M05FP-E2
IC771-----C0CBADC00072-----78L05L
IC773-----C0JBAB000715 -----TC7SH14F (HA)
IC521-----C0ZBZ0001708-----M81737FP
IC691-----C0JBAC000363-----TC7SH00FU


Thanks!
-Chris

Congratulations.


Crikey, big list. a lot there was probably ok. i'd almost be brave enough to say all that covers it. Only thing missing and small chance would be the 9856-2 opto which is rare but can blow.

I've marked a pic, not going to bother with too much since you've replaced all I'd consider normal.

Confirm what you get

[rockola1454]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

Hi!

So... I ran the resistance tests, but found some discrepancies I'm not sure quite what to do with. I double-checked all of my solder work just to be sure I didn't miss/short anything. Here is what I found:


[TP82] - Weird
I get 3 different readings depending on the range selection, but the readings are consistent across 2 different multimeters:
Range x <= 2000 Ohms: 1950 Ohms
Range x <= 20 K Ohms: 3.5 K Ohms
Range x <= 200 K Ohms: 4.1 K Ohms



[C561] - OK
5.6 K Ohms



[PC461] - Low by about 1 K Ohm both ways
Red-Blk: 5.03 K Ohms (you quoted 6.13 K)
Blk-Red: 4.78 K Ohms (you quoted 5.84 K)

*** These low readings are caused directly by my new replacement IC771. Pins 1 thru 3 left to right measure as such (desoldered):

Probe----------Original IC771-----New IC771
1(Red)-2(Blk)-----5.7 K----------5.0 K
1(Blk)-2(Red)-----5.8 K----------5.0 K
2(Red)-3(Blk)-----1650 K----------1820 K
2(Blk)-3(Red)-----infinity----------infinity

With IC771 desoldered, your PC461 (still soldered) probe test gives me:
Red-Blk: 100 K & climbs fast
Blk-Red: 45 K



[SC2] - Unsure
2+ Meg Ohms
(I don't notice it switch when lifting probe, but that might just be my meter)

*** I discovered tonight that my meter (a compact Micronta 22-169) cuts off at 2 Meg Ohm. I see SC2 climb up to 1999 K Ohm and then the screen blanks. I'm going to ask Santa for a Fluke for Christmas


Do any of the above seem like a problem, or are they acceptable deviances?

[tw2005]

Re: Panasonic plasma TC-P42G25 one LED blink, no power

Hi!

So... I ran the resistance tests, but found some discrepancies I'm not sure quite what to do with. I double-checked all of my solder work just to be sure I didn't miss/short anything. Here is what I found:


[TP82] - Weird
I get 3 different readings depending on the range selection, but the readings are consistent across 2 different multimeters:
Range x <= 2000 Ohms: 1950 Ohms
Range x <= 20 K Ohms: 3.5 K Ohms
Range x <= 200 K Ohms: 4.1 K Ohms

A meter that reads different on 3 ranges, i guess ok



[C561] - OK
5.6 K Ohms

ok



[PC461] - Low by about 1 K Ohm both ways
Red-Blk: 5.03 K Ohms (you quoted 6.13 K)
Blk-Red: 4.78 K Ohms (you quoted 5.84 K)

This one makes me nervous, could be just the meter since the results are varied. Double check D702 is not shorted, check it is in the correct way i.e, the anode and cathode are around the correct way. Why I'm nervous is from helping someone else thay had a figure close to 4.7k. If D702 is short you are effectively measuring across R711 which is a 4.7K resistor. If you get 5.7 with the original reg I would say ok if it only changes with the new one, variation in brands maybe. If D702 is in wrong or shorted , Q661 will blow and probably other stuff.

*** These low readings are caused directly by my new replacement IC771. Pins 1 thru 3 left to right measure as such (desoldered):

Probe----------Original IC771-----New IC771
1(Red)-2(Blk)-----5.7 K----------5.0 K
1(Blk)-2(Red)-----5.8 K----------5.0 K
2(Red)-3(Blk)-----1650 K----------1820 K
2(Blk)-3(Red)-----infinity----------infinity

With IC771 desoldered, your PC461 (still soldered) probe test gives me:
Red-Blk: 100 K & climbs fast
Blk-Red: 45 K

so it's obviously not shorted so ok, but testing results with items removed., I have no data with removed.



[SC2] - Unsure
2+ Meg Ohms
(I don't notice it switch when lifting probe, but that might just be my meter)

*** I discovered tonight that my meter (a compact Micronta 22-169) cuts off at 2 Meg Ohm. I see SC2 climb up to 1999 K Ohm and then the screen blanks. I'm going to ask Santa for a Fluke for Christmas

Probably ok


Do any of the above seem like a problem, or are they acceptable deviances?

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