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Re: Manky TT for sale on eBay.

Posted: Wed Jun 13, 2018 7:22 pm
by stephen_usher
I did say that it looked like leaking battery damage from the images on eBay.

Re: Manky TT for sale on eBay.

Posted: Wed Jun 13, 2018 7:24 pm
by frank.lukas
SCSI Port is done ...
scsiextern.jpg
scsiextern.jpg (982.06 KiB) Viewed 595 times
New must be: SCSI internal, Battery, Floppy internal, RTC and FDC Socket, ACSI, Floppy B and SCSI external and some Little Chips around the RTC/FDC Socket.

Re: Manky TT for sale on eBay.

Posted: Wed Jun 13, 2018 7:29 pm
by Atarian Computing
Nicely done. Looks promising.

Might as well do the RTC fix while you're at it.

Re: Manky TT for sale on eBay.

Posted: Wed Jun 13, 2018 7:45 pm
by Atarian Computing
Looks like there really isn't much corrosion on this side. The solder mask is good so traces are good. The bare (tinned) ground strip that goes around the board, and bare (tinned) area where the battery was are the only affected PCB parts on this side. And not badly at all.

Corrosion appears on some components in the vicinity of the damaged area. I would urge you to replace the RTC and FDC sockets as the battery alkaline can fester under the sockets.

For those who don't know, this is not acid damage, it's alkaline. It must be countered with acid. Vinegar is good for cleaning this.

Re: Manky TT for sale on eBay.

Posted: Wed Jun 13, 2018 8:49 pm
by mrbombermillzy
Atarian Computing wrote:
Wed Jun 13, 2018 7:45 pm
For those who don't know, this is not acid damage, it's alkaline. It must be countered with acid. Vinegar is good for cleaning this.
Also dont forget to do a final rinse with water, as you will now have an exess of acid on the board, which will have a similar effect to the alkaline melting ooze!

You may also want to check that DIN/VME RAM socket as the evil corrosive ooze stuff can creep UP terminals too :)

@Atarian: You seem VERY optimistic. This is the worst battery leakage damage I have ever seen in my life!

Anyway, good luck Frank :-D

Re: Manky TT for sale on eBay.

Posted: Wed Jun 13, 2018 9:13 pm
by Atarian Computing
mrbombermillzy wrote:
Wed Jun 13, 2018 8:49 pm
Atarian Computing wrote:
Wed Jun 13, 2018 7:45 pm
For those who don't know, this is not acid damage, it's alkaline. It must be countered with acid. Vinegar is good for cleaning this.
Also dont forget to do a final rinse with water, as you will now have an exess of acid on the board, which will have a similar effect to the alkaline melting ooze!

You may also want to check that DIN/VME RAM socket as the evil corrosive ooze stuff can creep UP terminals too :)

@Atarian: You seem VERY optimistic. This is the worst battery leakage damage I have ever seen in my life!

Anyway, good luck Frank :-D
All very true. Actually a very good point about the ST-RAM socket. Just like the resistor legs and the SCSI chip legs on the corner have a greenish coating, you can assume that it looks like that in the DIN socket. In fact, many TT problems arise from a similar DIN socket for the TT-Ram having bad or corroded connections. Only way to fix those for good is to replace the socket. Tuxie probably knows this the best.

I've witnessed amazing feats by fellow restorers that have just done stuff no sane person would dream to even want to attempt on severely corroded boards. This is very tame. So yeah, very optimistic about this even though I'm a pessimist.

Re: Manky TT for sale on eBay.

Posted: Thu Jun 14, 2018 4:19 pm
by Atarian Computing
Here are a couple of corroded PCB repair vidz:






Re: Manky TT for sale on eBay.

Posted: Wed Jul 04, 2018 3:47 pm
by frank.lukas
SCSI intern2_markiert.jpg
SCSI intern2_markiert.jpg (858.39 KiB) Viewed 452 times
I have some problems, these oxidized sites do not accept solder ...

Re: Manky TT for sale on eBay.

Posted: Wed Jul 04, 2018 4:00 pm
by rubber_jonnie
Is it possible to use a small needle to gently scrape away the oxidisation and open up the hole in the via?

Re: Manky TT for sale on eBay.

Posted: Wed Jul 04, 2018 4:10 pm
by troed