Jaguar Power issue

[sparf]

I have a new problem. This time it's an Atari Jaguar console. It simply doesn't power on. The power supply is good because it powers my other Jaguar up just fine.

Things I have done:

-Checked for bent pins in the cartridge slot.

-Cleaned the cartridge slot

-Tried a few different games, having cleaned each one and tested it on another Jaguar Unit.

-checked the board for obviously blown, bulging, or damaged components or solder points

-checked the nearest capacitor to the power connector, and a few others. Get potential voltage across many but not all.

-Checked the switch. Get voltage across its solder points/poles.


At this point I don't know exactly what could be fried. For reference, the system worked, then was put away, and when it was pulled back out during the brief time I owned a Jaguar CD, it simply ceased to power on. Also, its power adapter is different than the one with my other Jaguar. The one that came with it is marked for Jaguar (molded logo into the power brick like a Sega adapter, rather than the silver label that my working one has) does not power on my good system.

I'd love to see if I can get this working. No huge deal if I can't but Anybody have any ideas for me to try?

[MASTERWEEDO]

I also have a Jaguar that wont power on.

[raylydiard]

Try finding a 7805 regulator replaceing that fried part and will work again.

[sparf]

A 7805 regulator?

Sorry, but is that the part on the board, or the part I need to look for as a replacement piece, or both?

I found a chip that another site has shown and listed as a voltage regulator at U38. There is a tiny, tiny bit of discoloration as if perhaps it tried to melt but didn't melt all the way through. I'm attaching a picture of the whole board and the chip in question.

If that were to be the failed component, how should I go about testing it to make sure?

[bust3dstr8]

Look up the data sheet for that chip and test the inputs and outputs with a meter. I can't tell from this picture for sure, but if the chip has a discolored circle in the center there is a very good chance it's cooked.

[FABombjoy]

I've seen pics of U38 with a hole in the center, just about where that discoloration is visible. They are what typically fails in a no-power-on situation, especially after ruling out everything else as you have.

Shameless plug: I sell them here. Pinout and datasheet is here.

[sparf]

I've seen pics of U38 with a hole in the center, just about where that discoloration is visible. They are what typically fails in a no-power-on situation, especially after ruling out everything else as you have.

Shameless plug: I sell them here. Pinout and datasheet is here.

I may order one. I'm just concerned because while I could master enough soldering talent to solder a Sega CD power board with exploded caps and blown traces back into operation, doing SMT is a whole different animal. I don't have a multi-temp soldering iron/gun, nor the experience. :/

[bust3dstr8]

Those SOIC packages aren't any harder to solder than through hole.

You just need some magic sauce No clean paste flux.

Tack the chip down, then cover the pads and legs with a fair amount of flux.

Lay your solder across all the legs of the chip then bring your solder tip through the solder and hold

on the joint for a sec. The paste flux will keep legs from bridging and if there is any extra solder it will

be pulled onto the solder tip by surface tension.

[sparf]

Oh, Neat! But I should probably still have a temp-controlled soldering iron, yes?

Also, you don't happen to have any video or pics of this procedure in action do you? I'm curious what you mean when you say 'tack down' the chip. using the flux like glue on the solder points?

Those SOIC packages aren't any harder to solder than through hole.

You just need some magic sauce No clean paste flux.

Tack the chip down, then cover the pads and legs with a fair amount of flux.

Lay your solder across all the legs of the chip then bring your solder tip through the solder and hold

on the joint for a sec. The paste flux will keep legs from bridging and if there is any extra solder it will

be pulled onto the solder tip by surface tension.

[bust3dstr8]

He uses liquid flux, but it's the same method.

http://www.youtube.com/watch?v=-TGg7AUbUu8

[sparf]

He uses liquid flux, but it's the same method.

http://www.youtube.com/watch?v=-TGg7AUbUu8

THANK YOU! This is AMAZINGLY helpful!

I see videos on de-soldering ICs like that as well using various methods. since it's a known dead chip I don't have to be very careful if I bend its legs a bit. I could actually get some use out of the chip puller that comes with every PC repair toolkit that nobody ever has a use for.

So I should acquire some decent iron tips and some desoldering wick. Should I look for a special iron or would my standard Radio Shack cheapie work if I installed a smaller tip?

[sparf]

Nevermind. Really stupid question.