exxos's Atari, Amiga & retro forum

Hello,

Got recommended to join this forum by terriblefire as I'm looking at building a tf530. Going to look at doing a build log and ask a few questions when I get stuck slightly. First job for the Amiga 500 is to locate some ram chips to fix the Green screen on boot issue as re-seating the Agnus and Gary chips did not work unfortunately .

Anyway hello everyone.

Welcome... DiagROM and a serial cable is what you need

turns out chipram is potentially dead although it looks like the batter splurged in the past https://photos.app.goo.gl/r2J7fsx2qn2bssoWA

Those lines look pretty much gone, i'd guess those are the lines between Gary and the memory, so that would be my first avenue of attack.

Tip!, Watch out with fiber cleaning pen's, if you use them make sure to vacuum regularly as the little fibers can get stuck in your skin and irritate.

Maybe someone else has a better idea how to tackle that problem.

Ok, As i have an A500+ with about the same damage around here somewhere too I've already made an outline for the repair, these are the tips I already found:

Trace outlines needed for testi9ng after cleaning and after repair:
http://www.kipper2k.com/a500+/a500+exposed.jpg

Supplies:
1. Cotton swabs.
2. 5% vinegar.(dilute some with denaturalized water if needed)
3. Denaturalized water.
4. Isopropyl alcohol.
5. Fiber cleaning pen with extra fiber inserts.
6. Pcb cleaner for removing solder flux.
7. Pcb lacquer in the correct color.
8. Soldering tools.
9. Hot glue.
10. Different gauges of wire.
11. Replacement Parts.
12. Soldering skills.

First stop the alkaline from the battery from eating the affected area of the board any further:
1. Clean with 5% vinegar, keep that on there for 15 minutes.
2. Clean with denaturalized water, make sure to dry everything off afterwards.
3. Clean with isopropyl alcohol.
4. Use a fiber pen to clean all corrosion, make sure you take a look at all discolored tracks as it will eat the tracks underneath the PCB lacquer.
5. Remove parts that are damaged or can possibly have corrosion underneath them.
6. Use step 1-4 again if needed after removing parts.
7. Tin all exposed copper, take a good look at the via's and refill them with solder, remove to much solder with desoldering braid.
9. Clean the board with PCB cleaner.
10. Measure all the tracks that can be affected, especially test tracks with via's from beginning to end.

Personally I would wait a few days at that moment to make sure there is no corrosion coming back.

11. Make the repairs needed before new parts go on (for example U12?), fixate longer wires with hotglue.
12. After cleaning with pcb cleaner and isopropyl alcohol, use Pcb lacker to restore the lacquer on the PCB and let it dry.
13. Add new replacement parts.
14. Make any additional repairs with the new parts on, fixate longer wires with hotglue.
14. Clean with PCB cleaner and make sure everything is dry.
15. Test.

You wanted to make a build log for the TF534, but this repair could be a great thread too, copy any of the above if you want, a mention of my name would be appreciated.
Maybe some of the pro's could share some insight/tips too.

Hi Muteduck,

I definitely can aswell recommend to use PCBexplorer a very good site to check with a mulimeter the effected corroded traces & via-s . http://www.amigapcb.org/.

Mostly the Chipmem IC are fine,and the errors are mostly generated due to the corrotion of the leaked battery, causing traces to disconnect or a dead IC like U12 as already mentioned with Maximilian nice detailed step plan !

Anyway I hope you get your amiga to revive again

Nice!!, forgot about that one.

Wasn't that side made by one of the retroclub guys?

Hello Thanks for your help, been away for a few days Ill start a build log on the repair as it would be interesting and may help other in dealing with similar damage