Panasonic TX-P42S10B

[tw2005]

Re: Panasonic TX-P42S10B

Ok so pin 2 and 9 to the screen connectors?

VFG or VF-gnd are the metal gnd plates you had one of the probes on.

[tom66]

Re: Panasonic TX-P42S10B

Ok so pin 2 and 9 to the screen connectors?

It helps to have a meter with continuity, beeping when you make connection, and one which is fast (my meter responds within 1ms for continuity testing.)

Place probe on the floating GND and run it along the panel ribbons. Any beeps are bad, shorted outputs.

[tw2005]

Re: Panasonic TX-P42S10B

It helps to have a meter with continuity, beeping when you make connection, and one which is fast (my meter responds within 1ms for continuity testing.)

Place probe on the floating GND and run it along the panel ribbons. Any beeps are bad, shorted outputs.

I don't think his has that feature, might have to stick to diode and watch for the very low or zero reading.

[tom66]

Re: Panasonic TX-P42S10B

Set to 200 ohm IMHO, each buffer output has an antiparallel diode which you don't want to pick up. any reading different from "1" would indicate a potential short and should be investigated.

[noledud]

Re: Panasonic TX-P42S10B

on diode mode if i touch the pins i get a change to 000 its what iv always used to test for shorts

all boards using the above method show no shorts apart from the EMOS SD, its every single pin on that one showing a short

so if im using my DMM correctly then i should try using my buffers as we know for sure one SD is defiantly bad

[noledud]

Re: Panasonic TX-P42S10B

or should i go get a new DMM ?

[noledud]

Re: Panasonic TX-P42S10B

trying toms method i get the same results but can pin point the problem to the bottom IC of the SD

[noledud]

Re: Panasonic TX-P42S10B

and on closer of inspection i can see a defect in the actual IC very very very small

[noledud]

Re: Panasonic TX-P42S10B

just checked the SC again while the buffers are out and thats blown now aswell

the bad lower buffer must have blown it when i connected them up

am i right in thinking it wasnt the panel as my lower buffer is ok ?

[tw2005]

Re: Panasonic TX-P42S10B

or should i go get a new DMM ?

If you intend doing this a bit , I would. Like a good set of spanners, get something decent and it will last and pay for itself over time.

[tom66]

Re: Panasonic TX-P42S10B

If picking a new meter go for one with a fast and latched continuity range.

I use the BK 2709B you can see that you can run it right along a load of panel connectors and it will pick up a short really quickly.
https://www.youtube.com/watch?v=51SZ...Y&noredirect=1

Something like a good condition used Fluke, e.g. Fluke 87 or Fluke 27 is hard to go wrong with.

[tw2005]

Re: Panasonic TX-P42S10B

just checked the SC again while the buffers are out and thats blown now aswell

the bad lower buffer must have blown it when i connected them up

am i right in thinking it wasnt the panel as my lower buffer is ok ?

How did the SC blow?

You get the parts and fit them getting SOS 7.

Then I get you to isolate the SD/SU and jumper SC50, SC passes and TV powers on, no blinks.

We then knew that SC was good, and suspected we had bad buffers (possibly panel)

We then start testing the buffers and conclude the supplied SD is suspect and you've since confirmed a shorted output on one connector.

At what point did the SC blow?

[noledud]

Re: Panasonic TX-P42S10B

I put his sc and buffers in and got 7 blink, I then isolated his sc and got it to power up, I've then double checked it was all built correctly tried again and still got blink 7. Then I've pulled the buffers and started checking them. After confirming his sd was bad and mine looks good I wanted to try mine. While buffers out checked sc again and 7 blinks.

This is why I wanted sc and buffers to avoid this.

Well lesson learnt I'm going to get a new dmm send these boards back for exchange hopefully then test new ones first.

Do you agree that my panel didn't cause this because my lower buffer would be the same if it had ?

[noledud]

Re: Panasonic TX-P42S10B

Never heard any pop like some have described

[tw2005]

Re: Panasonic TX-P42S10B

I put his sc and buffers in and got 7 blink, I then isolated his sc and got it to power up, I've then double checked it was all built correctly tried again and still got blink 7. Then I've pulled the buffers and started checking them. After confirming his sd was bad and mine looks good I wanted to try mine. While buffers out checked sc again and 7 blinks.

This is why I wanted sc and buffers to avoid this.

Well lesson learnt I'm going to get a new dmm send these boards back for exchange hopefully then test new ones first.

Do you agree that my panel didn't cause this because my lower buffer would be the same if it had ?

Yeah, trying again once the Sc passed was a risky move especially when i said the buffers were most likely bad. If you found something obvious like the earth screws left out maybe worth a retry but we all learn the hard way sometimes.

You would assume that since your originals are not shorted then whatever happened to the SD was prior. Most likely a cracked screen whilst on blew the SD, SC survived the first time, not the second.

Exactly what happened to me except I only had myself to blame for not checking the buffers. 2 attempts SOS 7, blew it on the second and you could hear the quick pop.

general rule for me I always check any used sustain or buffres on arrival for shorts prior to installation now.

When I got my EMOS boards, they never left the box, tested short not only the Sc but the Buffers too.

It'll be interesting to see how you go now. Hope it works out. I guess you've done a quick check of the transistors to see what's shorted?

[noledud]

Re: Panasonic TX-P42S10B

Hi all

just to update

advised EMOS of the faulty parts and I want to return them

I never checked for shorts as I was fed up of seeing this set

took the boards in as they are not to far from my work

chap there went upstairs and "tested" the boards he agreed the bottom buffer had a short but the SC was fine !

he suggested replacing the bottom buffer would solve the issue

so with that information ( now doubting my diagnosis of faulty SC ) and new none shorted bottom buffer I went back home

fitted SC with no buffers did the jumper trick and still SOS 7

took all the parts back to EMOS again and the same guy checked the boards again he said they are all fine and "tested"

when I asked him how he tested he said he checked for shorts with DMM

I advised him they might not be any shorts where he is checking but the board is bad as I get 7 blink on its own

he told me I cant run it on its own and which point I gave up and told him I want a refund

so just had my refund from them but its shy of £11.75 iv asked why so waiting for a reply

I have a feeling it will be a re stocking fee or something as they have said the board is fine. I would have thought tho that the board would have been re sold and sent out by now so he should have another customer complaining but i doubt he would ever admit that