ms2250 rebuild

[ttocs]

as I am trying to clean out the left over parts I got from building the ms1000 when joerg comes up with a good deal/project for me and some of my left over parts. I am sure I will need some advise on what to do on this and if at any point I am doing something wrong please stop me. First was this 2250 board and the parts to put it back together. Its pretty clean and comes with two melted torroids and 2 good ones. Maybe Joerg can clarify a little more about what was wrong on the amp so I can check it prior to powering it up.

came with extra parts, power bars, fan board, some extra smaller coils if anyone needs anything please pm me and I will be happy to help anyone I can out.

Looking forward to soldering in the Nichicon caps that were included to do a full upgrade.


This one already had the big reisistor upgrade so It will probably end up in the ms1000 so it matches the other one.

First question: I have a bunch of small crappy soldering irons and a solder gun and a desoldering iron, but I really have no quality soldering iron. What would you recommend for a quality/easy soldering iron/station as I have this, the 1000, and the 430s I am going to be doing so I figure its about time to set up a station to do it right. My budget would be $100-150 but if I found one with a smoke vacuum system I might pay a little more.

[ttocs]

well after some looking around and pricing I decided to get a station with a few options. Heat gun, tweezers, smoke vacuum since I hate the fumes and now I can't wait to get started on everything.
https://www.amazon.com/gp/product/B00H3 ... UTF8&psc=1

Cleaned out my old work space in preparation and got started cleaning up the board. Went over it with some rubbing alcohol and found a couple of spots that worry me. First I found some kind of repair or modification was done here by the fuses and the speaker outputs.

and here is the other side?

not sure what they were doing there.

I have also found a couple of spots where the pads have lifted by the coils, and there is one power transistor that has now broken off the board... Any help on these?

[joerg]

The small solder spots next to the Speaker Outputs is where the red and black wire for the fanboard go. There was a fanboard included in the shipment. Other than that i did not touch the boards parts.

[ttocs]

No not the fan board inputs. the resistor sticking straight up and the cap hanging off of it. after looking at the two already in the 1000, its a stock modification. Strange looking as it is the cap/resistor are swapped I guess.

[ttocs]

Does anyone know what the value of Capacitor 323? Its missing and I would like to throw it on the parts list to order this weekend. Also curious if anyone knows what the wattage requirements are for the larger 1.5k resistors that have been swapped out for R345 and R346 I have one board that does not have it done yet, 2 that do now.

Thanks to everyone responding on here or pm. Its been a great help. The soldering/reheat station is arriving tomorrow and I look forward to starting in on this.

[trickyricky]

C323 is the same as C307 which is a 0.1uf capacitor.

For the resistors go 3 or 5 watt (just look at the datasheets to make sure they are not excessively long). 3.9K 1 or 2 watt for R343 and R344. The other side is 1.5k 3 or 5 watt R345 and R346

[ttocs]

grassyass dude!

is it normal to not be able to get the 1.5k ohm 3 watt resistor back ordered in quantities of 1000?

[trickyricky]

No, you should be able to get 3w in single quantities. I know I order a few from Mouser a month ago for a 2250 I repaired/serviced. They might have been 5watt, I'll double check and let you know.

[ttocs]

got my reworks/soldering station and set it up and was dying to try it out. Its amazing how fast it heats up and everything works perfect. The heated tweezers are just too damn cool imo but the smoke vacuum is really nice as well.



I got all the caps soldered in except the ones missing pads.



Should I take some of the capacitor pins and use those to try and repair the missing pads, or is there a better way?

[trickyricky]

The way you have those RAIL caps installed/inserted are WRONG! (From left to right, second and fourth snap in cap)...unless you just did that for the pic but haven't solder it yet. They should all have the negative side going the same direction. Eric has a great tutorial in his site (http://www.soundbuggy.com/Eric/Car%20Au ... index.html) for repairing damage through hole via's.

[trickyricky]

No not the fan board inputs. the resistor sticking straight up and the cap hanging off of it. after looking at the two already in the 1000, its a stock modification. Strange looking as it is the cap/resistor are swapped I guess.

They did this because the large 35 x 35 mm snap in rail caps was in the way.

[ttocs]

lol no i did that on purpose just to use the new rework station a little extra. Strange there were + markings on the board next to the cap spots but checking against the other two yer right.

Looking at the resistors, how can I tell the wattage? Looking at digikey now I see they they are available in multiple sizes and I thought size was what you judged them by? The two that are in this board are not in well, one side is loose already.

Also curious what you recomend for the coils. It seems a bit of a pain to try and get all the legs in there and then solder so just put one in and then solder it before moving to the other?

[ttocs]

ok got the two caps swapped. Thankfully i had not cut the ends yet and my desoldering bulb made it easy.

I am still curious what do to about the transistor that the pins broke off the board as I think I noticed another is loose.

In the extra parts I got from joerg there were extra power buss bars and a couple of them looked like they had a little better polish on them then the others, and from the way they were stacked/shipped the bottom plastic had worn off and needed to be replaced. I took the plastic off and was amazed how much better they looked after a quick cleaning as with two next to each other you can see your reflection in the gold. I will get some new heat shrink from the store for them and hope the new plastic is clearer then the old or I might consider some clear vinyl instead to preserve the polish.

[trickyricky]

As for the transistors with the broken pins, you can always use solder wick to tie them back together once you have the devices mounted to the heat sink. Just a small piece of solder wick on top of the broken pins and add solder.

On the transformer, you can solder from the top to hold down the wire or you can do one by one. I would alternate the soldering pins on the transformer and allow a minute to cool a bit before soldering the other pins (just to avoid excessive heat).

Looking at the resistors on your board, those are 3watt and I would leave them alone. If you want to replace them just measure them and get something near the same length.

[ttocs]

on the resistors they cut one too short and it isn't actually making contact, one other 2250 has smaller sized not sure what the power rating is on them.

Another reason I need more solder wick.....

[ttocs]

finally was feeling well enough to spend some time on this. I got the torroids installed and man was that pain in the ass. I still need to finsh soldering the top side but after repairing the via holes/pads that needed it I am happy. I realized while I was working on it this time that I will need the large glass fuse holders that go on the end by the fan board as they are missing. I think I could pilfer a dist block if I needed but I would hate to basically gut one for those little parts unless it was dead already or cheap. Anyone have any of those extra laying around? Still looking for 1.5k 5 watt resistors as well if anyone has a place to find those.

Also I almost forgot while doing some crap on my soldering station I happened to take out the filter to the smoke absorber and I was amazed to see that it was white/covered after just a short time of use. After seeing that if you guys do a lot of soldering I would recomend looking into a system like this. It just has a small tube that is 1/4" away from the tip that sucks all the smoke up as soon as its made. It was in the way a little last night where I had to take it off to get access to the torroids but it comes on/off easy enough.

[trickyricky]

I got some of those fuse AGU fuse holders in gold plate, let me know how many you need. As for the resistors I think mine are also in a white ceramic in 5watt, I'll double check and let you know.

[ttocs]

I need 4 of the fuse holders thanks again. I got the resistors out that I have and they are not all that much bigger then the ones that were already done on the one board. I would need to swap it out to match if I want to be picky about it but the board is out, the irons are hot so I probably will.

[ttocs]

got some more work done on it and repaired the via spots that had come out and got all the caps in. I also decided to go ahead and use the ceramic high watt resistors I got and they don't stick out that bad after all. What size are the smaller fuses supposed to be?