eMachines E15t3G problem

[EGuevarae]

I have an eMachines E15T3g monitor that is dead. The story is this:
A friend got this LCD from eBay with the AC input cut of from the cable (this monitors have the DC input socked attached to the end of the VGA cable just like some monitors have the audio cable). He opened it up, and soldered the plug back into the internal cables that he decided (yes , decided. Not traced, or discovered. DECIDED) were the DC input and after that, he plugged it in and boom : fuse blown instantly. He connected Vin and GND inverted, apparently, unless the ground signal is the one that is fused and then after the fuse goes directly to a (+) terminal of a 470uf 16v cap.
Well. Caps (Teapos) replaced, fuse reinstalled (he installed one new one and tried again. I installed the third and final fuse myself). There is DC input to some of the main board parts. I traced the voltage path up to the 1501-50 IC, where it is lost. I had another (dead) board from a Planar PT1500 that had that same chip, and tested it. While the one in the eMachines had the pins 3 (GND) & 5 (SD - shutdown/on) shorted (1 is V input), the one in the PT1500 did not. My problem is, how can you remove the IC in a way that it does not end up like the one in the 2nd picture,which was destroyed - literally - trying to be removed. I know that it looks like I tried to remove it with a fork and a knife, but I just applied some pressure on the bottom to try to lift it and ... well... see the pic
The third one is the full image of the board in question.

[PCBONEZ]

Re: eMachines E15t3G problem

Remove the legs one at a time first.
When the solder melts bend them up so they are clear of the pads.

Once all the legs are up then go after the heatsink. It will take a lot of heat to loosen that up. It helps to latch onto one of the lifted legs with a hemostat (something that won't let go of it when you do) so you have something cool to grab onto to lift it off.

If there are any parts on the other side of the PCB from the heatsink then make a little location map before you start so if anything moves or falls off (from all the heat) you can put it back after you get the new IC in place.

.

[EGuevarae]

Re: eMachines E15t3G problem

Well. I only have one (two) 30w Radio Shack cheap soldering irons, and I don't know if they can do the job. And no, there are nothing beneath the IC.
It is not soldered, it is glued. But I'll give it a try then. It is dead anyway.
Or I can just lift the pins, cut them and install the other one vertical, not flat against the board? It will stand the heat? The base glued is only GND. This just in case I can't lift the bad one. Not recommended (and not very aesthetic ...) but it can be done?

[geo]

Re: eMachines E15t3G problem

Have you made any progress on this problem? I have the same E15T3G monitor with the same problem. Pins 3 and 5 of the 1501 regulator shorted to ground. There is 12 V on pin 1 and 5 V on pins 2 and 4. All caps and other componets look good after visual exam.

Any tips on how to remove the 1501?
thanks

[EGuevarae]

Re: eMachines E15t3G problem

Have you made any progress on this problem? I have the same E15T3G monitor with the same problem. Pins 3 and 5 of the 1501 regulator shorted to ground. There is 12 V on pin 1 and 5 V on pins 2 and 4. All caps and other componets look good after visual exam.

Any tips on how to remove the 1501?
thanks

I was pulling it out of the "cold cases" box when this post's notification arrived. No, no progress, but will be working on it.
And welcome to Badcaps.Net

[PlainBill]

Re: eMachines E15t3G problem

I've never had to replace a chip like this, but here is the approach I would use. I HAVE use this successfully on other assemblies, including a tuner from a Series 1 DirecTiVo.

Get Chip-Quik kit, a heat gun, and some aluminum foil. Have needle-nose pliers or tweezers within reach. Unsolder the leads and remove them from the holes. Melt some Chip-Quik around the thermal tab. Mask the area around the IC with the aluminum foil. The idea is to have only the IC exposed. Now heat the IC up with the heat gun. Every few seconds poke at it lightly with a small screw driver or a dissecting pick. Encourage the Chip-Quik to merge with the solder. When the chip moves, quickly remove the IC.

Use solder braid or a solder sucker to remove the old solder & Chip-Quik. Clean the board thoroughly. Apply a small amount of solder paste to the board, mask the top of the new IC, then use the heat gun to melt the solder paste. Resolder the leads, clean up, etc, and apply power.

PlainBill

[Toasty]

Re: eMachines E15t3G problem

>>I only have one (two) 30w Radio Shack cheap soldering irons<<
Time to step-up your game as I suggested before. 45w or better. Otherwise, prepare for more chip butchery.

>>remove them from the holes<<
They are pad soldered.

Seconded! on the Chip-Quik It brings the solder melt point down to that of boiling water or less.

CUT the legs with 1) component lead cutters/nippers 2) X-acto razor saw 3) Dremel tool cutoff wheel. Much less stressful to the pads. Then desolder each leg. Grab individual legs with your small needle nose pliers or hemostat, then heat the pad with the soldering iron. You don't "sink" the heat to the component and it takes just a touch with the iron to break them loose.

It helps to pre-heat the board with a hair dryer. If you can, keep it going on the back of the board while you heatgun the chip as PlainBill directed.

Solder paste is a must for reinstallation. I am curious as to members "Brand" suggestion for the product. Some say Kester, others nay-say Kester.

[Toasty]

Re: eMachines E15t3G problem

@geo
>>...Pins 3 and 5 of the 1501 regulator shorted to ground. There is 12 V on pin 1 and 5 V on pins 2 and 4...<<

Just a plain 1501? Or 1501-## -33 = 3.3v, -50 = 5.0v, -12 = 12v, no number is adjustable voltage. If you have the one here, 1501-50, and 5v on pin 2 then it's working.

Pin 3 IS ground. Same as tab. Lift pin 5 to confirm short to ground. Other voltages you gave don't "look" wrong.

Pin 4 is the feedback to the regulator to adjust the PWM.

[geo]

Re: eMachines E15t3G problem

It is an Anachip 1501-50. I could not find a datasheet for it so I'm using the AMS1501-50 datasheet which should be the same.

The Pinout is:
1 Sense
2 Adjust/ground
3 Voutput
4 Vcontrol
5 Vpower

The voltage the device sees on Vcontrol is about 7.3V (pin4-pin2) so Voutput should be about 5 volts.

If you know pin 3 to be ground, could you please point me to a better datasheet.

I will pull the pins as you suggested.
thanks

[Toasty]

Re: eMachines E15t3G problem

Here:


or

http://www.alldatasheet.com/view.jsp?Searchword=1501-50

[EGuevarae]

Re: eMachines E15t3G problem

Time to step-up your game as I suggested before. 45w or better. Otherwise, prepare for more chip butchery.

That was a month ago, man... now I have a 45w fine tip one (not the big brand, but quite far from what I had when started).

[Toasty]

Re: eMachines E15t3G problem

Sorry. I didn't look at date.

We've covered a LOT of territory in a month. LOL

[EGuevarae]

Re: eMachines E15t3G problem

Sorry. I didn't look at date.

We've covered a LOT of territory in a month. LOL

Yes, it has been a long hard road to hell...no, wait, that's a song.... sorry, I guess that the prescription PCBONEZ gave me for my insomnia is kicking in ....too much Modelo Especial for one night. Have you ever played any Resident Evil series Game while half drunk , after 4 days of barely sleeping, on a dark room , alone in your apartment/home/whatever?.
I'm going to start killing Zombies with my soldering iron .... I'm gonna burn them
Did I mention that I'm half drunk?

Now, for a more serious statement, yes, there are so much material learned, reviewed, passed on, and more importantly, FIXED, in that month...hey, that deserves a little celebration !!!! let me get fully drunk instead of just half drunk....

[Toasty]

Re: eMachines E15t3G problem

No RE. But Doom III, in a dark room, with full surround cranked, and a great subwoofer makes for a heart pounding night! EEEEKKK!!

[EGuevarae]

Re: eMachines E15t3G problem

No RE. But Doom III, in a dark room, with full surround cranked, and a great subwoofer makes for a heart pounding night! EEEEKKK!!

I had Wolf 3d, Doom, Doom II, Heretic & Hexen originals, bought as they came out,but were stolen. I never had the chance to play Doom III, but I've seen it, and it should be awesome. The scariest RE I've played under that conditions, was the remake of the first RE, for the Gamecube. In the silence of the night, you can hear the screaming, the laments and the Zombies knocking on windows trying to break in... in a stormy, windy night, on a mobile home (that was moved by the strong wind...) that was really scary....
RE5 was Launched yesterday at 12:01 Am nationwide (on a Friday 13th, what a convenient date...) on GameStop stores. I reserved a copy and I'm playing because I can't sleep anyway. You should have seen the release of Metal Gear Solid 4 .... there was a guy that was exactly dressed and his face resembled Solid Snake down to the very minimal details ..... oops,I got carried away. Honey! Another Modelo please!!!!

[Bobdee]

Re: eMachines E15t3G problem

CUT the legs with 1) component lead cutters/nippers 2) X-acto razor saw 3) Dremel tool cutoff wheel. Much less stressful to the pads. Then desolder each leg. Grab individual legs with your small needle nose pliers or hemostat, then heat the pad with the soldering iron. You don't "sink" the heat to the component and it takes just a touch with the iron to break them loose.

Hello again
Many thanks for info,
I could do the above with confidence if I had to, but as a hobbyist the rest of your post I would be wary of.
I would get over this by improvising,
RE: Carry out your above suggestions, then Bond the new one on top of the old ones body, and then solder legs to pads,
This would need some tweaking of the legs by bending them down a bit more so they reached the board,also making a judgement as to where precisely it is fitted on top so as legs reach pads,
my understandig is that the backplate does not need to be grounded, but if it does then I would solder a wire from old plate to new one.
( I bring this up to help others like me, as there have been capable people, make errors on this type of thing,)
I have never done anything like this before but I think it may turn out to be a reasonable and safe fix.

Solder paste is a must for reinstallation. I am curious as to members "Brand" suggestion for the product. Some say Kester, others nay-say Kester.

As someone that knows nothing about solder paste, can you explain why it is a must for this job, and why,???

Thanks in advance for any new input,
bob

[PlainBill]

Re: eMachines E15t3G problem

Hello again
Many thanks for info,
I could do the above with confidence if I had to, but as a hobbyist the rest of your post I would be wary of.
I would get over this by improvising,
RE: Carry out your above suggestions, then Bond the new one on top of the old ones body, and then solder legs to pads,
This would need some tweaking of the legs by bending them down a bit more so they reached the board,also making a judgement as to where precisely it is fitted on top so as legs reach pads,
my understandig is that the backplate does not need to be grounded, but if it does then I would solder a wire from old plate to new one.
( I bring this up to help others like me, as there have been capable people, make errors on this type of thing,)
I have never done anything like this before but I think it may turn out to be a reasonable and safe fix.


As someone that knows nothing about solder paste, can you explain why it is a must for this job, and why,???

Thanks in advance for any new input,
bob

The tab of the IC was soldered to the PC board for thermal dissipation. (The copper ground plane is used as a rudimentary heat sink. Simply bonding the new IC on top of the old would result in the new one overheating.

HOWEVER, your idea does have merit, just modify it slightly. If space permits, leave the old IC in place after cutting off the legs. Mount the new IC vertically and attach a small (1" x 3") piece of copper or aluminum as a heat sink.

Solder paste is a mixture of finely ground solder and flux. It is used to solder surface mount ICs in place. It's advantage for this application is a thin layer can be spread on the back of the IC. When the IC is heated to the melting point of the solder it quickly fills the space - no need to apply heat long enough for a wicking action. I shudder to think about trying to use a soldering iron and wire solder to do the job. Wikipedia has a brief article on the subject.

As far as which brand is better, this is a question for someone active in electronics manufacturing, specifically in surface mount components. And I'm sure that it's not a matter of which manufacturer, but which 'series' of products. Unfortunately, my contacts to the industry were nearly 20 years ago.

PlainBill

[geo]

Re: eMachines E15t3G problem

Thanks Toasty, The Anachip does have a different pinout than the AMS part.
Looks like the observed voltages are OK as you said, so I will look elsewhere for a bad componet.

[Toasty]

Re: eMachines E15t3G problem

Solder paste adheres the chip to the surface initially. Over several hours, it evaporates its solvent and leaves the chip ready to be heat-gunned back onto the board. The chip should haves its legs bent and formed but not soldered down until after the tab is connected. Some boards have a larger copper area under the chip that acts as passive cooling for the device.

That's why I believe it should be reattached to the board as the original was.

More info:
http://www.howardelectronics.com/chipquik/smdrepar.html

http://www.howardelectronics.com/chipquik/products.html