Anyone have a link to repairing a DC8?

[derek_s]

Mine has fried 2 ports, for unknown reasons, one of them being a very low amp draw. I contacted the mfg but they want quite a bit to repair it.

I am an electronics guy, so I could probably do it myself if I had access to some kind of diagrams or similar. Anyone seen such a publication/post?

 

[derek_s]

Haha, I may let you know on that. The 2 ports that seem fried are permanantly locked to the ON position, so its not all that bad. But whats the point of that, right?

Anyways, I have not opened it up since I first got it (I installed an external fuse access instead of the silly internal one). At that time, maybe 8 months ago, it looked brand new on the inside. I dont think it would have corroded that quickly considering it's location in my stand (screwed to the top). But anything is possible. I'm not sure what would cause it to lock on... Relays sure dont usually do that. I wonder what type of switching module it uses?

 

[enderg60]

yeah i had the same problem on my old DC-8 but by the time i got around to removing it to send it back, my return hose poped off and it fried resulting in no warrenty

call up neptune BTW, if you just ask they may tell you how to repair it or at least ask about getting a replacement at cost. They felt bad for me when that happened so they let me get a new one and a dc-4hd at cost. Still not cheap but better then nothing.

 

[derek_s]

I emailed them...no mercy..

 

[enderg60]

call them. its harder to say no to a real person

 

[mojo]

Most controllers use triacs for switching these days - relays simply don't stand up to long-term abuse (although they're better for non-inductive loads). Depending on how handy you are with electronics, you could pop it open and trace the circuit to find the bad component and replace it.

Most controllers will use either a) some kind of bus-to I/O chip (resulting in the typical 8 channels from 8 bits in a byte) or b) a more direct approach, driving 8 channels direct from the uP (either parallel or even bit-shifted, though that'd be stupid in this case). I'd be willing to put money that the DC8 uses the a) version - it'd be idiotic to do otherwise.

Anyway, you should be able to identify the I/O chip easily. Using a working outlet as a guide, trace the connections and components until you find one that doesn't do what it's supposed to.

My guess is that it's the triac or it's pull-up/down resistor that's blown, and would probably be a straightforward fix.

 

[derek_s]

I am somewhat familiar with Triacs and IOs. I opened this thing up and it is pretty simple. I just tested through it and found 2 triac that are testing erroneously. I cant read the card labels or the terminal labels to find out which terminals are the gate/t1/t2, but the two are testing significanly different that the other 6 across the terminals in various configuratins.

Chris, if you were gonna order some triacs, where would you look? THey are :

B1A12
600BW

I always have trouble finding components online since I dont order them very often, and Iwouldnt think Fry's would have them?

 

[mojo]

You can try http://www.jameco.com">Jameco</a> - a tad bit more expensive, but no minimum charge, or [IMG]http://www.digikey.com/">Digikey</a>, which is bound to have something, but a $25 min charge.

But most likely any triac that is similar rating will work. I'm doing a couple searches right now to see what I can find for you.

 

[derek_s]

Ok. I found some at Ace electronics, from who I recieve a flyer occasionally. They have some, but the #'s dont match. They seem to mostly go by amperage, so I guess I just need to make sure that the A are similar and the T1/2/gate are in the same locations.

 

[mojo]

http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=1385133&">Here you go</a>. 25A, 600V triac. I assume you're looking at a TO-220 case- this should be a drop-in replacement. Unfortunately, it looks like there's a 1000 unit minimum...

[IMG]http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=808026&">This</a> would probably work as a substitute.

 

[mojo]

corvettecris;255358 wrote: Ok. I found some at Ace electronics, from who I recieve a flyer occasionally. They have some, but the #'s dont match. They seem to mostly go by amperage, so I guess I just need to make sure that the A are similar and the T1/2/gate are in the same locations.

Ideally, the current, voltage, and gates should match. Here's the datasheet from your part- I'd try to either find the exact one or one that matches at least on the above params, plus Vgt (max 1.3V) - you don't want to overdrive the triac...

 

[derek_s]

Yes it i a TO-220

So you think the substitute will suffice? The amperage seems significanly lower (8 vs 25)???

 

[mojo]

If you're pulling more than 8 amps on those outlets, you've got some issues anyway.... However, there's the issue of inrush current, which could potentially be 20 amps for a ballast or motor or something.

It'd probably be best to search around and find something that matches a little better. Use Jameco and see if you can come up with something. I've got to go take care of some things; let me know if you can't find anything, and I can try to look later tonight.

 

[derek_s]

When you get a chance, check out this one. The data sheet you meant to post for my part didnt show up, but maybe this one is good.

 

[derek_s]

BTW, do you think it would be unethical/illegat to post a DIY on how to repair this? I think it mat be useful to folks in the future, and may apply to RKs as well.

 

[derek_s]

Honestly, after seeing the inside, it would be a pretty simple build. Not too complicated at all, but I;m not really keen on programming teh IOs. I assume that is easy as well given the burning equipment and know-how. But the physical assembly is simple.

 

[mojo]

Derek_S;255441 wrote: When you get a chance, check out this one. The data sheet you meant to post for my part didnt show up, but maybe this one is good.

http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=1385037&">http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=1385037&</a>[/QUOTE]

That one looks pretty darn close to me. I say go for it!

[QUOTE=][B]Derek_S;255511 wrote:[/B] BTW, do you think it would be unethical/illegat to post a DIY on how to repair this? I think it mat be useful to folks in the future, and may apply to RKs as well.[/QUOTE]

Absolutely not unethical or illegal. People do stuff like this all the time. You're not exposing any company secrets or anything. It'd be one thing if you were trying to sell a competing product based on a reverse engineering of this one, but you're not. If anything, you're helping their business.

Besides, a product like the DC8 isn't rocket science or anything terribly cutting edge, esp. when it sounds like I described the electronics without having ever cracked one open...

 

[derek_s]

Jameco was out of stock until Feb, but I found it on Mouser, so I ordered 5 of them. Hopefully I can get this going soon.

 

[derek_s]

Fixed. I can post a how to if there is any interest?

 

[mojo]

Awesome- it was the triac, then?