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SX-1010 won't Power On...

D.E.K said:
Also, when I tried to desolder the components on the circuit board I am practicing on, the tips were all bent shut onto the circuit board. So even though I got rid of the solder, I had difficulty taking out the components because of that. In some cases, the green surface of the board just peeled off.
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When the pool of solder is liquid, you use the tip of the iron or some sort of heat resistant tool to lift it up. If they're really tight, I use the tip of an x-acto. You just have to get a feel for the timing. That's one of the reasons why the weller iron tips I have available to me generally have a screwdriver shaped tip.

You can also push on the lead or component from the other side while the solder is liquid, then you don't have to touch the molten puddle, possibly cooling it.
 
markthefixer said:
When the pool of solder is liquid, you use the tip of the iron or some sort of heat resistant tool to lift it up. If they're really tight, I use the tip of an x-acto. You just have to get a feel for the timing. That's one of the reasons why the weller iron tips I have available to me generally have a screwdriver shaped tip.

You can also push on the lead or component from the other side while the solder is liquid, then you don't have to touch the molten puddle, possibly cooling it.
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Good idea. Thanks a lot.
 
D.E.K said:
Any news on the DC Feedback Path or do you want me to say to heck with it and order the outputs?
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Looks like we have to install at least two outputs per channel, and depend upon the dim bulb tester to save out assets. Before we power it up we have to have a long discussion. You can install two transistors per channel, a pnp and a npn.


863-MJ21193G pnp to-3 250v 16A 250W 4mhz 8-75hfe replaces 2sa & 2sb transistors
863-MJ21194G npn to-3 250v 16A 250W 4mhz 8-75hfe replaces 2sc & 2sd transistors.
 
LONG DISCUSSION ----> Perfectly fine. I suffered the consequences of not having THAT discussion (although you emphesised that in bold, capital letters) and jumping the gun earlier. So no problem, even if it takes weeks to get a little bit of improvement.
 
Mark, I am having the items ordered tomorrow or the next day. Should get them sometime next week. I am getting 4 PNP, 4 NPN, 2oz compound and 10 mica insulators. I was planning on getting 5 PNP and 5 NPN but unfortunately, budget too tight. Thus, no room for errors. I will let you know as soon as I get them... WITHOUT putting any of them on.
 
D.E.K said:
Mark, I am having the items ordered tomorrow or the next day. Should get them sometime next week. I am getting 4 PNP, 4 NPN, 2oz compound and 10 mica insulators. I was planning on getting 5 PNP and 5 NPN but unfortunately, budget too tight. Thus, no room for errors. I will let you know as soon as I get them... WITHOUT putting any of them on.
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Okey dokey
 
Mark, I just posted a new thread related to a problem with SX-950. I'd appreciate if you took a glance at it.
 
Hi, I just wanted to say that the goods arrived today. I am ready when you are Mark. :thmbsp:

P.S: The compound has to be 2 'fluid' ounce as it is quite a big tube. 1 oz is ~28 grams and I don't see tha tube being only 56 grams. It is much heavier than that.

Cheers...
 
First, NO power on.....

Second, dim bulb tester ready?

Third, install the 8 transistors:

a. Warning the 2 holes in the mica insulator for the transistor leads are offset from the center, so which side up is important. figure it out with the mica dry first.

b: There is a small "lip" on the socket that fits into a recess on the heatsink's holes, misplace this and as you tighten the screws it will break the socket.

c. get the socket up on the heatsink first and slide it a bit, you will feel it hit and "lock" into the recess.

d. Put a Thin coat of white goop on the back of the transistor, then some on the heatsink, about the size of the mica, you want minimum squeeze out.

e. put the mica on the transistor, it will stick, making it easier to get the assembly into the socket.

f. insert the transistor into the socket that is pushed up against the back of the heatsink, then insert the two screws and gently tighten it down. Gently alternate torquing the screws in. Watch that lip, that you're not tighteniong down on it, it has the added advantage of keeping the leads and screws centered.

g. take an ohmmeter, and find a bare spot on the heatsink where you can touch BOTH probes and read zero ohms, then while leaving ONE probe touching the bare spot, probe the two pins and body of the transistor to be SURE there are no short circuits to the heatsink anywhere.

H. CAREFULLY put back the thermal diodes, being SURE the wires are not broken.
.
 
Understood. I got familiar with the lip and the way the transistors match with the insulators. Simplest I can put this is: one way, the holes don't match and the other way they do. No problems so far except one. Remember the broken "hoof" on one of the STV-H3 horseshoes? I really NEED to take readings and make sure that it is okay. Just need to know how. I don't want to blow these PNP and NPN's to kingdom come as they cst quite a bit ad taks a nice bi oftimeto arrive. I also need to use a small washer to secure it onto the heatsink.
 
Oh also, the dim bulb tester I used the first time is down in the basement, ready for action. Nonetheless, I will take the "FRESH MIND AND HANDS IN THE MORNING" advice and not attempt anything tonight.
 
Don't rush, take your time.

Take part of an old mica and use it between the broken horseshoe and the washer just in case...

Visually verify the wires to the horseshoe are not broken.

Readings are the checking for shorts now. That's it.... and remember - no power -.
 
No power, no worries. Last time I checked the wires were not broken. I will let you kow how it goes tomorrow.
 
Mark, are you sure you don't want to try with 2 transistors per side? I can install ALL 8 of them no problem. Let me know.
 
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