[sdiy] BP Electrolytics & Obscure Solina ICs?

[Michael Ruberto]

Peter,
Thanks for the helpful info! I agree about the tca350, BBD chips are a 
nighmare to source lately.

Regarding the console I'm now thinking the corrosion I see isn't caused by 
cap leakage afterall. I desoldered some of the caps off the PCB and after 
inspecting them I don't see signs of leakage on them. The bottoms of the 
caps and the areas where the leads connect are clean. I now suspect the glue 
that was applied to them. The glue on the BP caps is darker than the glue 
used on the other caps around the PCB. Where this glue comes in contact with 
any metal there is heavy corrosion. OTOH the glue on the polar caps is a 
light color and there is no corrosion where it comes into contact with 
metal. The smaller caps which aren't glued at all have no corrosion near 
them either. Is it possible they used a glue formula that became highly 
acidic over the years?

The more distressing situation with the console is these:
http://i108.photobucket.com/albums/n13/somnium7/gear/toa_input_amp.jpg

See the big black cube? It's a discreet amp module. Pure unobtainium. Some 
of these have burned out. The burned power resistors near them and the 
cracks in the potting make this pretty apparent. I'm now cannibalizing 
sections of the mixer to fix more mportant sections because of these things. 
Today I got curious and took one of the line-amp units outside with a hammer 
and a screwdriver. There isn't much inside! Two unmarked TO-220 transistors, 
a HA-12017, and a few passives. I'm thinking I might be able to cobble 
something together to use as replacements!

Some suggestions on this could be very helpful...

M. A. Ruberto

>From: Peter Blackett <dragonser at clara.net>
>Reply-To: dragonser at clara.net
>To: Michael Ruberto <frankentron at hotmail.com>
>Subject: Re: [sdiy] BP Electrolytics & Obscure Solina ICs?
>Date: Sun, 06 May 2007 22:27:29 +0100
>
>Dear Michael,
>from what I can rememeber the TDA0470 is a transistor array, TCA350V is a 
>BBD delay ic, and the
>SAJ110 is a divider ic.
>probably the tca350v is the hardest to find.
>
>http://www.organservice.com/crm/topdividers.htm
>might have some replacements.
>
>I'm worried to hear about the electrlytic caps leaking in your mixing 
>desk.......
>I've heard of problems before with some ( but not only ) Japanese equipment 
>from the early  1990's due to problems at one of the electrolytic capacitor 
>manufacturers .
>but I think that as the equipment gets older more caps will be needed to be 
>changed.
>regards Peter
>
>
>
>
>Ruberto wrote:
>
>>I am trying to find a cheap source of BP electrolytics for the repairs on 
>>my mixing console. All the BPs in it are leaking and leaving a path of 
>>corrosion behind. Mouser has Nichicons for 40 - 60 cents in the values I 
>>need but I'm looking at 32 channel modules, 4 sub modules and 8 program 
>>modules each containing several of these caps. At Mouser prices this will 
>>cost me a fortune.
>>
>>I'm also deciding whether or not to take on a repair job for an Arp 
>>Solina. I'd love to work on it but have no idea where to find the exotic 
>>ICs such as, TDA0470, TCA350V and SAJ110. I can't even find datasheets for 
>>these. Any ideas?
>>
>

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