corrosion on the board(pioneer)

[heyhi]

I took apart a pioneer head unit that wont power up.the owner said it stopped working after his battery died.the bottom of the board is full of corrosion and theres a b1238 transistor that i found broken. few questions ... 1 is the corrosion bad for u ...
2 what can i use to clean it...
3 where can i find this transistor...
4 what could of caused this corrosion....
thank u guys for the help again I'm new at this but I'm learning so bare with me and if u have any ideas of what to look at feel free to voice Ur opinion oh and if any 1 knows where i can look to learn about radios of this type id appreciate it

 

[killivolt]

I'm not guru about radio's but maybe it is a 2sb1238. And I have no Idea how this one is used in your circuit. So, with that said I will say I've seen the corrosion come from bad Capacitors leaking electrolyte on the board. A good electronic circuit board cleaner will help. Make sure you get some backup on this cause when I looked about this part their were several types and uses. It may well be your undoing without a parts list and schematic.

 

[kchriste]

It could be a 2sb1238. Check this datasheet and see if it looks remotely like it:
https://www.datasheets.org.uk/pdf/256789.pdf
The corrosion could be anything. Treat it as toxic if you can't identify it. Use gloves and eye protection when cleaning it off with alcohol or a circuit board cleaner. You could use a toothbrush for scrubbing. Don't brush your teeth with it afterwards.

 

[Bob Scott]

What do you mean by "head unit"? There are a lot of different types of heads.
Guitar amp head?
Tape head?

 

[heyhi]

its a car radio and i also found a broken transistor 2 pins where snapped off is that normal i doubt it

 

[Bob Scott]

It sounds as if the board is corroded due to being submersed in water and now it is too late to save because all the conductors are impregnated with contamination. The legs of the transistors are corroding off and will continue to do so no matter how much you try to clean them. I've seen this before.

It is possible to recover from water submersion by flushing with fresh water and then blow drying, but not after a day of delay. And not if power was applied while contaminated.

 

[heyhi]

i hope its not from water the guy said his battery died in his car and thats when it stopped working i don't see any water marks or signs of leaky caps I'm gonna replace the transistor and see how it goes any 1 know where to get a pioneer radio schematic. when i apply power to it the face briefly gets power to it for about a half a sec and goes off again but the screen is blue .

 

[Nigel Goodwin]

i hope its not from water the guy said his battery died in his car and thats when it stopped working i don't see any water marks or signs of leaky caps I'm gonna replace the transistor and see how it goes any 1 know where to get a pioneer radio schematic. when i apply power to it the face briefly gets power to it for about a half a sec and goes off again but the screen is blue .

If it's got corrosion on the board, then it's had some corrosive fluid inside it - most probably water (but urine isn't unknown, and is far worse! ).

In Chesterfield (a few miles from me) there's a bridge with a dip underneath a railway line, with traffic lights on it. In extremely wet weather it floods in this dip, and I was asked to look at an in-car amplifier that was removed from a car that tried to go through when he really shouldn't have! The car had totally died under the bridge, with the boot (trunk) completely full of water, and the amplifer sat under mucky water for a few hours until towed out.

Needless to say it wasn't a repairable item!

 

[heyhi]

where can i get a schematic for a pioneer deh-p2600

 

[blueroomelectronics]

where can i get a schematic for a pioneer deh-p2600

You might be able to purchase a service manual from Pioneer.

BUT it's likely not designed for any sort of non factory service as are many modern consumer electronic devices, so getting a service manual might prove to be impossible.

ADD to that it's a code (theft deterrent) device, so they probably wouldn't sell such documents to anyone except ceritified Pioneer service shops.
**broken link removed**

 

[heyhi]

theres plenty of schematics on line but i was wondering if any 1 knew of anywhere to get free schematics

 

[blueroomelectronics]

If you mean the $5 service manual, that appears to be a bargain.
**broken link removed**

 

[rjvh]

not only fluid will corode your PCB
also the fumes of it

in my work i deal a lot with corroded print boards
(control units in water filtration)
as soon a seal of the housing is breached or cracked the problems start
chlorine gasses are very agressive and eat copper away in no time
at this moment i am in the field and not in my office work shop but i will post you the pictures later
also had to repair one time a TV where a flower vase with water was fallen in
the water containd fertilizer and i could get the TV working again

half yer later it came back and the whole PCB was conducting i think it whas the salt in the fertilizer

or geckos that nest in equipment and pissing over the whole print
the protective coating on the PCB is not so protective against that

Robert-Jan

 

[Nigel Goodwin]

also had to repair one time a TV where a flower vase with water was fallen in
the water containd fertilizer and i could get the TV working again

I generally write those off, as you found out, any 'repair' is generally only short term, continued corrosion is likely to make it fail later on.

I've also got no sympathy for idiots who put vases of flowers on their TV!