My junior is trash...

[0078265317]

Yes buy how do I remove the 7805 in the first place.

[yllawwally]

To remove the 7805. Have the atari upside down, and apply the soldering iron tip to one of the legs, until the solder melts. Then remove the iron and quickly flip the atari over and tap it against the table. That cause most of the solder to fly off onto the table. The solder will burn wood tables, so make sure you do it over something you do mind ruining. Then repeat the process on the other two legs. The using pliers grab onto the 7805, and wiggle the 7805 while heating each of the pins. It's not very hard to pull out, just be careful to not pull off the traces.

One you get the replacement 7805, make sure you put it in the same way the original was. Then you can heat the legs up one at a time, and apply some solder, until the hole is filled.

[0078265317]

I'm no good with electronics. I finally got the regulator out and made 3 clean holes. But I ripped off some of the green stuff on the board next to the one of the holes. See photo. So it is officially junk now I guess.

 

[shadow460]

To remove the 7805. Have the atari upside down, and apply the soldering iron tip to one of the legs, until the solder melts. Then remove the iron and quickly flip the atari over and tap it against the table. That cause most of the solder to fly off onto the table. The solder will burn wood tables, so make sure you do it over something you do mind ruining. Then repeat the process on the other two legs. The using pliers grab onto the 7805, and wiggle the 7805 while heating each of the pins. It's not very hard to pull out, just be careful to not pull off the traces.

One you get the replacement 7805, make sure you put it in the same way the original was. Then you can heat the legs up one at a time, and apply some solder, until the hole is filled.

 

I've stayed quiet on this thread so far, but I have to correct some things.

 

The way of removing components that's described here is highly likely to ruin circuit boards and components alike. There are a number of methods of desoldering. The easiest one for the home user is a $15 desoldering tool from Radio Shack. "Tapping" solder from a soldering tip is one thing, but trying to tap it from a motherboard just invites further physical damage to the board. Even if you get "most" of it off, that means a tiny bit remains. That's why you get ripped traces like what's happened here. On top of that, tapping solder like that is dangerous. You can't see what's being removed or where it's flying to.

The ripped trace is totally repairable. I've had several fully working consoles that had traces ripped and bypassed. In the picture above, a piece of narrow gauge solid wire could be run from the affected leg of the new 7805 to the leg on the opposite side of C36. The problem, however, is that with the case busted up so badly, you likely have physical damage to the motherboard in other places, which would be what's keeping the system from working to begin with.

 

My recommendation is to save the three major ICs from the board. If they're still OK, they can be used to repair another console or sold to someone who does repairs. It's always a shame when classic gear is lost to physical damage, but there's not a whole lot that can be done about it after the fact.

 

Oh, one other method of removing small semiconductors is to lay a flat part of the iron tip across all three legs (working under the board), then push the device out after several seconds.

Edited February 13, 2013 by shadow460

[Andromeda Stardust]

5.3V sounds about right for the output. 3.8V might be the difference between the adapter and the 5V line. 5.3V + 3.8V = 9.1, so that looks about right for the adapter. The black output may be the result of a bad TIA or any number of components. I wouldn't really know where to begin.

[Andromeda Stardust]

Hmmm, I didn't see there was a page two. You need to be really gentle when desolddering components. A tiny bit of solder will remain even when using a bulb or braid. As the solder melts on one side, you can tug the component very gently from the other side. Thing is it takes almost zero force to slide out components when the solder is melted, but it usually takes only about a second for the solder to reharden. When I replaced the 5V regulators and "chicklet" capavitor on my four switch Atari, a couple of traces lifted up slightly, but the damage was extremely minor and all the components soldered in successfully. For components with two or three leads, it's possible to rock them back and forth as you heat alternate leads, but larger chips like IC circuits need to be have the solder vacuumed out completely in order to remove. It is best to have a lot of solder practice and at least a slight working knowledge of the types of components before you attempt to do repairs on old circuits.

 

Rather than trying to remove the CPU and TIA chips from their sockets, it may be better to just ship the PCB board by itself to someone who can refurb it. A lot of people buy broken consoles and refurb them back to life as a hobbie. Often the components from two broken consoles can be combined into a working one. If the case is cracked and broken, it's no use sending the plastic bits, and the Jr board should be small enough to fit in a small packet first class or priority box.

Edited February 13, 2013 by stardust4ever

[0078265317]

Well to late I already took out the regulator. Back to the trash I guess.

[yllawwally]

Go ahead an solder in the replacement 7805 when you get it. Like Shadow460 said, you can repair the broken trace, by soldering a wire from the center leg of the 7805 to c36.

[0078265317]

Go ahead an solder in the replacement 7805 when you get it. Like Shadow460 said, you can repair the broken trace, by soldering a wire from the center leg of the 7805 to c36.

 

I'm sorry this is already getting way more complicated than I expected. And I have no more wires. If you like pm me your address and I'll send it to you for free and you can play with it for parts. Otherwise today is trash day and its going.

[Andromeda Stardust]

I'm sorry this is already getting way more complicated than I expected. And I have no more wires. If you like pm me your address and I'll send it to you for free and you can play with it for parts. Otherwise today is trash day and its going.

Don't throw it out. Post just the circuit board for free (+ s/h) in the marketplace forums. Somebody will want it. I don't do refurbs as a hobby due to the amount of clutter it generates, but a lot of people on this forum do refurb and repair old consoles and they would be happy with anything you can provide them.

[yllawwally]

I don't have need of another unit. I'm sure someone will take it off your hands, if you post in the marketplace, as stardust4ever suggests.

Edited February 14, 2013 by yllawwally

[0078265317]

the.golden.axe agreed to take it off my hands. So we'll see in a few days.

[gohmc]

Well if you wanted to try to fix it. The first thing would be replacing the 7805. It's legs are large and are pretty easy to solder. They should be under 2 dollars at a radio shack.

Yes they are and yes the previous was right they are easy to solder especially if you have good soldering skills. I had to replace the voltage regulator on my Atari 7800 Pro system and it took around 5 min to do the initial solder work and around another 5 or so min to make sure that it had a good and solid connection with the system.