Another Pioneer SX 1250 restoration

I always give the big can caps a visual check for leakage and find the most recent stabilizer board rebuild . Its the 1250's Achilles heal .
 
Hey guys, some of the caps on the stabilizer board are glued and sticking to the board like crazy. How do you get rid of it? I don't want to use too much force, to not damage the board. Some heat from a hairdryer maybe?
 
Grab them with a pliers - twist left and right to break the glue free - desolder and pull them off.
 
Just desoldered all the caps from the stabilizer board and tested them. All but one were good. The little sucker C6 was dead... Waiting for my Digi-Key delivery...
 
Hi folks,

of course I paid too much, but I wanted to have that unit. Faceplate is more or less ok, the usual scratches and bumps, but nothing extreme. Lights are all burning, but no sound. Neither via headphone, nor via speakers. If I am not wrong, I can't hear the relay clicking at the start, so maybe that's all? Fingers crossed! By the way, does anybody have an idea what the replacement type for the relais is? The service manual is saying ASR-015, may I use the OMRON MY4-02-DC24?

Thanks, Boris
View attachment 968929

Great amp to do a full build on! :)

If you check other posts you can see what is recommended. Such a fun build, the 1250 has a lot of good room to work with.

Congrats! Looking forward to seeing the build!

Kind Regards,
John
 
Grab them with a pliers - twist left and right to break the glue free - desolder and pull them off.

Please tell us you are not serious about pulling components off with pliers?

Im no pro, but that is a very bad idea. you can damage the PCB.

Im probably misunderstanding something... Nonetheless, for glued down caps, a hot blade works wonders.

Use a Desolder gun, solder sucker, or solder wick. If you do need to use pliers, id be super carful.

Kind Regards,
John
 
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Hey guys, some of the caps on the stabilizer board are glued and sticking to the board like crazy. How do you get rid of it? I don't want to use too much force, to not damage the board. Some heat from a hairdryer maybe?

Take a butter knife or a putty knife, heat it up. The blade will melt the adhesive.

that adhesive is common in old JBL gear as well...
 
As I said before the first place to check is the stabilizer... caps, transistors, and diodes..
 
The pliers and the left right are only to crack the glues contact, not to pull the cap off the board. It is done first; so you don't have to desolder and unglue at the same time.
 
The pliers and the left right are only to crack the glues contact, not to pull the cap off the board. It is done first; so you don't have to desolder and unglue at the same time.
Correct - jeepers, you don't just rip them off!
 
Ok, protection board has new caps and a new relay. Regarding the transistors I am a bit unsure. I ordered parts according the confirmed replacement list. It's saying
2SC1166 (2SC1384) to be replaced with 512-KSC2690AYS. What Digi-Key delivered (left) looks a bit different from the original (right)... Is that the right one? (sorry, blurry picture...)
IMG_0453.JPG
 
There are a lot of unoriginal parts on that board mostly transistors,also a very big 2-3 watt resistor in the middle of the board that I never saw on that board before. Please follow the parts list and replace all the parts on that board, not just capacitors. It's a very easy board to work on. I've already attached a parts list for this board, somebody was in there before and I kinda don't trust their replacements. Also dont forget the trimmer resistors. The KSC2690 is a suitable replacement dont be alarmed by its size.
 
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There are a lot of unoriginal parts on that board mostly transistors,also a very big 2-3 watt resistor in the middle of the board that I never saw on that board before. Please follow the parts list and replace all the parts on that board, not just capacitors. It's a very easy board to work on. I've already attached a parts list for this board, somebody was in there before and I kinda don't trust their replacements. Also dont forget the trimmer resistors. The KSC2690 is a suitable replacement dont be alarmed by its size.
Thanks for the advice. Just checked a couple of pictures in the net and yes, you're absolutely right. That board has some strange parts on it. Guess it will take a little bit longer than initially thought...
For the 4 big filter caps I took a bit of risk and ordered some no name caps from ebay - coming from hongkong... hopefully they will be ok...
 
Ok, got rid of all the transistors on the stabilizer board. The soldering points on the back were questionable, don't know who did what on that board...
fullsizeoutput_456.jpeg
And here is the patient - still a lot to do...
IMG_0471.JPG
 
Thanks for the advice. Just checked a couple of pictures in the net and yes, you're absolutely right. That board has some strange parts on it. Guess it will take a little bit longer than initially thought...
For the 4 big filter caps I took a bit of risk and ordered some no name caps from ebay - coming from hongkong... hopefully they will be ok...

Yes you took a risk getting big caps from China. Mouser and Digikey have nice perfect fits caps that run about $22 each.

http://www.mouser.com/ProductDetail/United-Chemi-Con/E32D800HPC223MD79M/?qs=sGAEpiMZZMukHu%2bjC5l7YRVHbWh2qrfWdXeaBhiu1VY=
 
I took a bit of risk and ordered some no name caps from ebay - coming from hongkong
hopefully they won't be like this. :no:
RUICHI CD60.jpg

Best case scenario you will get crappy weird branded caps with bad specs that can harm your hard work, I've removed hundreds of that garbage on several "serviced" units.
Is always better get quality parts from reputable brands (Panasonic, Nichicon, Nippon-Chemicon, etc) and from reputable sources (Mouser, Digikey, etc) specially for this monsters:thumbsup:
 
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