50" LG Y-sustain IPM modules

[mbates14]

I have a sustain module i removed from a 50" toshiba plasma, although i believe the panel is LG. along with all of its drive electronics.

it uses the yppd-j015b and 016b chips. one heatsink was cold to touch, so i removed the IPM and it is physically blown.

the other IPM, 016, gets warm to the touch so i didnt remove it.

anyone know where to locate these IC chips besides a broker in china?

[PlainBill]

Re: 50" LG Y-sustain IPM modules

Six auctions on eBay.

PlainBill

[mbates14]

Re: 50" LG Y-sustain IPM modules

Six auctions on eBay.

PlainBill

I was afraid you were gonna say that. i dont use ebay for electronic parts anymore. ive been burned way too many times, already ordered a new sustain board on ebay, got it, it was bad, had to send it back.

and that wasnt the only time. hehe.

[PlainBill]

Re: 50" LG Y-sustain IPM modules

I was afraid you were gonna say that. i dont use ebay for electronic parts anymore. ive been burned way too many times, already ordered a new sustain board on ebay, got it, it was bad, had to send it back.

and that wasnt the only time. hehe.

Look at the feedback rating of the seller, and his product line.

Buying a used sustain board from someone who has a 95% feedback rating selling mostly shoes is a bad idea.

Buying an IC from someone with a 99.7 % feedback rating selling electronic parts is pretty safe.

PlainBill

[cadiman]

Re: 50" LG Y-sustain IPM modules

If I think I am taking a risk I pay or bid low. I found an inverter board on ebay for 20 bucks with shipping. The curcuit board was a half inch longer than the box. The seller had 5 transactions. The board worked. I gave the seller positive feedback then sent him a nice friendly messege. Plainbill is correct.... as always. I wish I could see better than I look and listen better than I can hear....Wisdom is a wonderful thing!

Good advice Plainbill

[mbates14]

Re: 50" LG Y-sustain IPM modules

ok well, i bought the 2 new IPMs. the j015 and the j016.

the j015 and 016 i ordered looked ok physically, and tested physically fine with no shorts.

put them in, same problem. no picture, and the J015 heatsink stays cold. but a new problem crept up, the J016 starts to overheat, never did this before. All fuses check fine, all power is going into the sustain module. Maybe the 195v isnt making it to the J015 IC, but the 016 is overheating now. it wasnt before....

So i took the old J016, it physically looked fine, and dry diode checks dont reviel any shorts so i stuck the old one back in there. still overheats now. hmmm.....

but the J015 stays cold. I scoped the SUS-UP and SUS-DWN drive signals comming from the control board, they are present.

any ideas?

[mbates14]

Re: 50" LG Y-sustain IPM modules

18V supply to the IPMs read 2.3v. J016 overheats, so the culprit is probably J016 pulling too hard on the 18V supply.

removed J016 again, checked real close inspection, see a hole in both J016 MOSFET dies, reads shorted on the meter with both my old one and the new one. so the new one was already blown, the visible blown hole in the die is VERY hard to see without a magnifying glass, so it probably got mistaken as a good IC and tossed in the good pile. all of the die level diodes test fine, no leakages. they survived. only the MOSFETs died.

J015 looks ok. going to try a pair of IRFP250Ns tomorrow connected to the IC to replace the blown FETs, already cut the bonding wires. the resistors and diodes are not bad on the ICs driver bd. they survived as well. so the mosfet just popped/shorted without taking even the gate drive resistor out. it is still intact and good.

so the only conclusion is the gate driver IC is trying to drive the shorted mosfet, taking the 18V straight into ground. thus causing the overheating of the IC.

wish me luck....

[cadiman]

Re: 50" LG Y-sustain IPM modules

The faulty 15-18v supply is what finished off my ipm on my 50 L/G The heat took out the caps. ( Z board ) My y board is still running. ( was replaced already ).

[mbates14]

Re: 50" LG Y-sustain IPM modules

Update:

SUCCESS!!!!

Put in the new IRFP250 MOSFETs into the old IPM.

Found 18v still 2v with neither IC in place.

Found the 0.15ohm resistor nearly open, output diode off inductor shorted. replaced both. supply went up to 5V but it was stuck at 5V.

Scoped the 18V regulator, i noticed there was no dwell period or flux line ring from the inductor. replaced inductor, scope reading was now correct.

18V supply restored.

Re-installed the ICs, and powered up the TV. WORKS!!! has a beutiful picture once again. no overheating or signs of stress detected.

my rework job paid off.... no more expensive IPM replacements. hehe.

So repairing the bad J016 and the bad parts in the 18V switching regulator fixed the set.

I will upload the pictures of what I did to the J016 module a little bit later.

I also socketed the ICs. so if it ever needed replaced again, i can just pop the ICs out, do the repair/replace and pop in a new one.


I also fabricated clamps so the ICs just wont "fall out" from heat/vibration.

[mbates14]

Re: 50" LG Y-sustain IPM modules

Victory was short lived...

But i think its my fault though...

It was working beautifully, turned it off and unplugged it. then went to go plug it back in and turn it on. i got nothing but white vertical bars where the menu is supposed to be.

if i input a signal, i get alot of blue mal-discharge and the TV shuts down.

i think its from removing and reinserting the ribbon cable into the sustain module 50000 times. because if i twist or push on that cable a little bit, the screen will change from white vertical bars with some blue mal-discharge, to almost non-visible vertical white bars and flashing/beating raster.

I guess its just the cable. But ill find out tomorrow for sure.

so im gonna try and locate another ribbon cable, as that carries all the y-scan signals, and sustain/ER signals. which will cause the vertical white bars. I checked the IPMs again and they didn't fail. no shorts. so its gotta be something stupid.

[mbates14]

Re: 50" LG Y-sustain IPM modules

found 2 of the SMD power MOSFETs on the lower y buffer shorted. Replaced, and shes playing once again ;-)

[Turning]

Re: 50" LG Y-sustain IPM modules

Hi, mBates

What temperature soldering iron are you using; or, a better question; how are you removing the IPM's?

I have had difficulty desoldering them. I have a 50x3 ( in a maxent case) that has been my project for a couple years. But, as an engineer, it only makes sense to repair the components instead of replacing an entire card, as I have been doing.
I believe I'm slowly losing the Erase IPM on my Sustain board, but I can't seem to easily remove it without damage.

What do you think?

Turning

[fastvideo]

Re: 50" LG Y-sustain IPM modules

Hi, mBates

What temperature soldering iron are you using; or, a better question; how are you removing the IPM's?

I have had difficulty desoldering them. I have a 50x3 ( in a maxent case) that has been my project for a couple years. But, as an engineer, it only makes sense to repair the components instead of replacing an entire card, as I have been doing.
I believe I'm slowly losing the Erase IPM on my Sustain board, but I can't seem to easily remove it without damage.

What do you think?

Turning

I have the same question here.
It took me at least 45mins to remove it and with 2 traces damaged.

[cadiman]

Re: 50" LG Y-sustain IPM modules

There are posts on this topic.
I break off the old chip at the screw with the twist of a screwdriver. You can loosen the screws a bit with needle nose vicegrips to get a screwdriver between the chip and heat sink. Cut each pin one by one then desolder each pin wth a butane iron and clean with a small drill bit.
I solder the chip in then install the heat sink last with small allen bolts and nuts.

I was not in a hurry to do another one!
Good luck!

[father_fixit]

Re: 50" LG Y-sustain IPM modules

I will upload the pictures of what I did to the J016 module a little bit later.

Did you post the pics?

[Wizard]

Re: 50" LG Y-sustain IPM modules

What's the IPM? And where do 18V comes from? On samsung, the 15V comes directly from the main power supply board.

Cheers, Wizard

[PowerAmpFreak]

Re: 50" LG Y-sustain IPM modules

Last time I removed one IPM I used a special compressed air de-soldering gun which we have in our shop, also we have super wide soldering irons which is 2 inch wide. This covers most of the pins on the IPM, one side at a time.

[mbates14]

Re: 50" LG Y-sustain IPM modules

im back. the buffer ICs eventually totally took a shit after a few minutes on this TV, the guy pretty much got a new one so i got stuck with this one. So basically, I got a junk chassis with a good panel. looking for a panel-swap candidate for this little/big guy. However.......

I removed the sustain module and stuck it in another 50X3 with blown IPMs and it ran for about 5 minutes before the IPM blew out again.

18V is hanging around 16.3V on both Y sustain boards. so im suspecting that low voltage is causing the issue. but i did capacitance and ESR checks on those SMD caps and through hole caps, they are all fine. thats not the cause of my low B+ Something else is.

Also, the 18V is derived from the 5V supply on the board, via a step-up boost converter circuit. this circuit resides directly under the ER IPM heatsink. This was IMHO, the most stupid idea ever. but i guess since the toshiba sets that I have, used sony power supplies, they had to do it this way. i guess... who knows.

The ER IPM survived the re-failure of the SUS IPM.. So i got 2 good ER IPMs, (1 rebuilt, 1 stock). and no good SUS IPMs


So... the only thing left to do is remove the Z-sustain from the first 50X3 that is junk now, and remove its IPMs to be placed into the Y-board again... problem is, i gotta find out whats going on with that 18V supply, or guess what, shes gonna blow again.

[mbates14]

Re: 50" LG Y-sustain IPM modules

I forgot to note, there is an 8-pin PWM control IC that drives that 18v regulator. they are all within the same spot of the 18V regulator.

What i do is have both IPMs removed, have the bare board sitting on the bench, and I hook a lab power supply up to the 5V rail, set it to 5V, and test my 18V output.

this is the safest way to test the output of the regulator, without having all these rampid high voltages around while testing in the set, risking probe slippage and blowing shit up like i normally do.

I have the pictures, I just have to get them off of the camera. besides, I rebuilt the ER IPM and she held up just beautiful. its the SUS IPM that blew, but i stuck a regular unrebuilt known good ER IPM in its place to eliminate that as a factor, before it blew out, and it blew out anyway.

[PowerAmpFreak]

Re: 50" LG Y-sustain IPM modules

I'm curious how you actually rebuilt the IPM?
When checking a discrete Y-SUS board, I can actually see three "legs" of halfbridges with corresponding IR bootstrap gate drivers (like in class D audio amps). So, what can cause a class D amp to dissipate heat?
if there are bad gate drive supply or cross conduction in the main switches, maybe this can be the case even on a driver board for a plasma TV.