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[Wai]

Thank you Xenepp, I'll definitely give that jumper wire idea a go; however, I'll have to get my physics teacher's permission to solder the wire at school (I don't have that sort of equipment at home). I'll just repost the image here again since your BBCode is broken:



The corrosion that you referred to is the blackened gunk, correct?

Now, can someone tell me whether it's necessary to replace the old battery after taking it out, or just let the SMD800 function without a battery altogether?

How do you unsolder something? I know how to solder components together, but how do you undo that process?

[Xenepp]

Best to ask your teacher how to de-solder, he should be happy to tell/show you.

[Wai]

I have Sonic 3 and Knuckles on my Sega Saturn, which functions perfectly fine, so I'll just leave the SMD800 battery out from now on. Even if my SS battery goes flat and I lose the memory, I can easily replace its battery without having to solder anything.

I'll let you guys know how I go with fixing up my SMD800. Thank you so much for all the help you've offerred!


Edit:

Its seems like the acid has eaten through the gold-coloured layer and into the copper (which is now pitch black in colour in that area). Should I cover that area up with something to help prevent further corrosion in place of the gold foil?

I bought a new 220 ohm resistor to replace R7. However, I think its tolerance is different. The new 220 ohm resistor has a tolerance of 1% (brown), but R7 had gold or silver (the acid had eaten up the band so I couldn't exactly tell what colour it was). Would it be okay to use the new resistor? It was only available with a tolerance of 1%.

[Xenepp]

Yes, it will be fine if the old resistor was rated 220 ohm.

If the copper is gone too, you can't do anything to replace it, just make sure ALL the corrosion is gone around it. If it was just part of a ground plane it doesn't make that much odds, but if it was a trace then you will need to jumper it. Do you have a pic so I can show you what I mean?

-Joel

[Wai]

Did you mean this one?



The acid has corroded part of the copper layer, but how do I remove that if it's stuck solidly into the circuit board? I'll have no problems soldering a jumper wire between the points you indicated. I just need some assistance removing the corroded copper (as a chemistry student, I know that the corrosion will eventually spread to other areas around it).

[Xenepp]

You can use anything that is abrasive, so long as you are careful. I use a fiberglass pencil but you can use sandpaper (very carefully), pummis stone, even a stanley blade (being VERY careful). You will eventually get to the copper under it or fiberglass of the PCB if the copper is gone. You won't need to jumper anything other than that wire I showed you since the ground plane will still reach where it needs to.

If you have a dremmel tool, I'd use one of the buffer attachments on that also. It will take a little time but is safer than using a harsh abrasive with a dremmel, though you could use a grinder attachment with the dremmel switched off.

Joel

[Wai]

I have removed most of the corroded gold foil covering the copper layer with various tools. However, I think the acid has corroded the copper layer too. The copper layer under that blackened area seems to have darkened (corroded). How do I remove the corroded copper layer area?

Do you have MSN? Maybe it's easier for us to communicate that way. I'll be online for a few more hours. If you have MSN, PM me your addy and I'll add you.

[Xenepp]

PM sent.

-Joel

[Wai]

I finally found the wire that was disconnected by the battery leakage. On the mainboard, it's the wire which runs on the right hand side of the R7 resistor (from your perspective). The disconnection is at the point where the wire and the leg (the one closer to you) of the R7 resistor meet (I think they were supposed to be connected). Are they supposed to be connected? I hope the chips haven't been damaged, because I haven't noticed any corrosion on them.

Edit: I have included an image of it, with the green-labelled wire being the disconnected one.

[mrforever]

so you have solved non working problem?

[Wai]

No, I'm still waiting for a response as to soldering that disconnected wire. Is it connected to the R7 resistor or not?

[CrackLtd]

If it helps: I have the same unit, i can make super close up pics of both sides of the pcb and post them here. Just let me know.

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#ToToTEK Channel on EFNet

[Wai]

Yes, that would be very helpful. I'm no good at photography. Either that, or I don't know how to adjust the settings on the camera lol.

[CrackLtd]

Ok, here we go, but beware, these pics are HUGE! Both pics show a
SMD800. First front, 2nd back. The little ramboard got removed to
show the full main pcb. Notice that the battery is removed too. (If you
look very closly you can see the battery did little damage, 4 traces
located below the battery and left of the ramboard connector got a
little black corrosion. However, the unit is still fully functional!)

[Wai]

Thank you so much for posting those photos. I don't think the wire is connected to the R7 resistor, so trying to solder a jumper wire may be a little more tricky.

I didn't have any battery leaks underneath the mainboard, but the top surface had a fair bit of corrosion to clean up. I found myself a compass (the things that draw circles) and used the sharp point to scratch off the corrosion, which wasn't too difficult after I removed that wretched battery. I hope that disconnection in the wires is the culprit - if any of my chips are damaged, then I'm screwed lol.