42px5d-eb no picture

[wreksta]

hi all
I have here a 42px5d
the set powers up with no picture not sure on sound as the imput wont switch to hdmi only idtv

opened the set up up all voltages from psu are fine check out ok
vs va etc all as it should be

so I checked fuses on x and y board

x fuses are fine
y fuse isn't the one closest to the ipm is blown this is a 250v 4a fuse
thing is I replaced it with a 250v 3a fuse but set wont turn on turnson clicks the relay then back to standby

do you think if I put in a 4a fuse it would work I don't have one atm but will get

[tom66]

Re: 42px5d-eb no picture

Nope. The IPM is bad. Replacing the fuse has just put a short circuit across power supply. You need to replace IPM -- difficult job. Or replace Y-sus -- if you can find one.

[wreksta]

Re: 42px5d-eb no picture

id prefer to replace ipm im quite good wth a soldering iron

[wreksta]

Re: 42px5d-eb no picture

will replacing ipm deffinatley fix the set
and this one isnt soldered both sides or is it

anything else to check mate before replacing the ipm

[tom66]

Re: 42px5d-eb no picture

Quite good -- well it depends on your definition but you really need to be confident in removing a 30pin+ IC which is heatsinked on both the board and the top, and has very large heat-sucking copper traces. Yes, it is soldered both sides so you really need to suck the solder out good.

I could not do it; one of the reasons I don't bother with these awful IPM LGs.

If you can't do it properly, be sure not to damage the board. The sustain boards are virtually unobtainable, if you damage it beyond repair.

[wreksta]

Re: 42px5d-eb no picture

bit the bullet got another ysus and buffer

but now set refuses to turn on and I have no reading at power board

[tom66]

Re: 42px5d-eb no picture

Don't rule out your new Y-sus being bad. Test IPM for shorts from VS to GND, VS to SUS OUT and GND to SUS OUT.

[wreksta]

Re: 42px5d-eb no picture

done that on ipm fuses are stil good but I have no voltages with this board in place

[tom66]

Re: 42px5d-eb no picture

Check VS to GND on Y-sus then.

[wreksta]

Re: 42px5d-eb no picture

all voltages normal now no fuses popped but still no screen

how do you check buffers on these
or any other checks I should carry out

[attainteddragon]

Re: 42px5d-eb no picture

hey wrek, you need to do resistance checks on the ipm.
remove the board to access the legs of the ipm.

[wreksta]

Re: 42px5d-eb no picture

dne that mate cheers theres no short im considering changing ipm but theres something got to be at fault on this board

[attainteddragon]

Re: 42px5d-eb no picture

if you have voltage at the fuse and it hasnt blown, and your ipm has checked good,
if this set has two buffer boards, disconnect one and see if you get half a picture.
some photos would be good.

[wreksta]

Re: 42px5d-eb no picture

I have 1 buffer mate I disconnected yboard from buffer can I run it like this cause I tried and heard pop cant locate nothing or smell anything
ill post some pics soon

emos tv parts have agreed to a refund but I want this working not my money bk

[wreksta]

Re: 42px5d-eb no picture

tom is it bad to test tv without buffer connected to y board

well turns out this board is defective but I aint got time to wait for a replacement so im going to switch ipms and hope

[tom66]

Re: 42px5d-eb no picture

No problem without buffer connected.

[wreksta]

Re: 42px5d-eb no picture

well I transferred the ipm and theres no shorts n it I checked but still no picture any clues

I wil try swapng the other buffer in all voltages are correct from psu to ymain
z main etc


what am I missing

[tom66]

Re: 42px5d-eb no picture

What volts across any one of the bank of red poly capacitors near the IPM?
Pics would help as we are working blind here.

[wreksta]

Re: 42px5d-eb no picture

tom here some pictures







which poly cap do you mean and across whats that mean grnd and then the positive on the leg or both leads on either end

[tom66]

Re: 42px5d-eb no picture

Across here.
Putting both leads on one end would lead to a reading of zero.
Put one lead on one end, one on other. Ignore negative sign on meter.

If Y-sus is working, expect around 50 to 150V DC. Should match Z-sus.