What's new
What's new

Looking for schematics for a Mitsubishi MDS B SP 220 Servo Amplified

Mcgyver

Diamond
Joined
Aug 5, 2005
Location
Toronto
worlds worst typist....title should be amplifier not amplified. I'm looking for schematics for a Mitsubishi MDS B SP 220 Servo Amplifier....any chance any of you has such a thing or can suggest how to get them? Mitsubishi's web site doesn't offer them.. The servo amp stopped working, no light on the front (but there's power on the DC bus) and repairing it seems hopeless without schematics

thanks
 
Based on my experience on other items in there range you will not find it. You may well find unique OEM component level parts though from china on E bay which i have replaced things like the actual touch screen display in a control unit and such for a tiny fraction of as new pricing.

Power on the DC bus is kinda meaningless, its pretty hard to damage any drive in such a way as to not still have that. Its far easier for output stages and control boards to be damaged, that would be a small supply in there some were providing the logic level voltages for the control side, i would try and ID that and chase it from there. I don't give you good odds though. Trouble shooting this stuff can take hours and even then its more than possible non replaceable bits.

if you have any output details, see if you can measure a output on any of the encoder lines - pin outs.
 
Based on my experience on other items in there range you will not find it. You may well find unique OEM component level parts though from china on E bay which i have replaced things like the actual touch screen display in a control unit and such for a tiny fraction of as new pricing.

Power on the DC bus is kinda meaningless, its pretty hard to damage any drive in such a way as to not still have that. Its far easier for output stages and control boards to be damaged, that would be a small supply in there some were providing the logic level voltages for the control side, i would try and ID that and chase it from there. I don't give you good odds though. Trouble shooting this stuff can take hours and even then its more than possible non replaceable bits.

if you have any output details, see if you can measure a output on any of the encoder lines - pin outs.

thanks. By mentioning the DC bus working, I just meant there's power to the unit. I did find an non working 2" onboard fan directed at a mosfet on a heat sink. I took the mosfet out and it seems ok, but there was a daughter board in very close proximity to the mosfet that looks a little dodgy. the daughter board is a DK510A BN634B836G51 - Home - Yaspro Electronics and the IC is a M51996 - a switching regulator. I'm guessing by proximity that was the controller for the mosfet, if its pooched it explains no power on the board
 
Go careful also on the fan thoughts, more than a few drives have fans that only come on based on actual measured temps not permanent run.

Define dodgy looking mosfet a bit better if you will? I have encountered plenty of dead ones that look brand spankers. Key problem mosfets are pretty tough but like a lot of solid state components can and frequently do damage there driver circuits when they fail, hence if it truly is dead replacing it is a bit of a crap shot, on the plus side it is a pretty cheap crap shot.
 
Go careful also on the fan thoughts, more than a few drives have fans that only come on based on actual measured temps not permanent run.
.

it was very gummed up to the point where it wouldn't turn freely, something inside, bearing seized or dried out grease? tried it off the board with a bench power supply and nothing

Define dodgy looking mosfet a bit better if you will? I have encountered plenty of dead ones that look brand spankers. Key problem mosfets are pretty tough but like a lot of solid state components can and frequently do damage there driver circuits when they fail, hence if it truly is dead replacing it is a bit of a crap shot, on the plus side it is a pretty cheap crap shot

the way I phrased that was not clear, its the daughter board that looks off, possibly heat damage, not the mosfet. The daughter board was bent over slightly such that it was in contact with the mosfet. I took the mosfet out and did they diode setting test, and current to the gate seems to properly turn on/off the drain/source connection. I thought maybe a hot mosfet damaged the daughter board touching it - I'll a get good photo of that board that'll be more descriptive than 'dodgy'
 
Somewhat to my surprise, I manage to fix this. The non working fan pointed at a fet and a daughter board that looked a little burnt. A leap of faith with an unknown Chinese board vendor (courier was as much as the board) and a new Fet and believe it or not it worked!

Maybe they are all as bad, but I have a hate on for Mitsubishi from this. Seems terrible that you discontinue a product and won't make the schematics available. What are you suppose to do - throw out your who machine because THEY decide to discontinue something? Sure they want you to buy new, instead it makes me not want to buy anything form them again. Grrrr.

Anyway, I pulled all the other modules in the machine and will replace any fans. If mitsubishi was a great as they think they are, the non working fan should have triggered an alarm before the circuit burned up.
 
Congrats on the fix!

Sadly, Mitsu are really no different than any of the other big control manufacturers. Fanuc might be a hair better in that at least they do (or used to anyway) print a "block diagram" of their drives and will sell discrete components if you have a P/N. You won't get that from Yaskawa, Mitsu, Okuma, etc. On the plus side though they are so well made that it's pretty rare to have them fail considering the numbers in service.
 
Honestly lots of fans have bearings, if there permanently on they very much have a life expectancy of x years, less if hotter or dustier environments, hence replacement every dozen or so years is not exactly a bad call, nearly all semi conductor electronics last significantly longer when ran at a lower temp.

Congrats on the fix, you beat the odds on that one.

Pretty much no one will issue circuit diagrams any more, oftern basic block diagrams, but beyond that your on your own, do to the amount of stuff that gets copied, it is kinda no wonder though. Equally ever more circuits run on std but programmed chips, hence simple replacement is only half the process. Add in surface mount rework tasks and this stuff is getting harder than it ever has been. One of the intresting circuit digrams you can still get is for apple products though, but i don't believe its through official channels. Even then do to the amount of integrated circuits performing some pretty complex stuff its far more akin to a wiring diagram than a circuit diagram of old. Deep multiple layer boards are also the norm and fault finding gets ever harder.

I use to do a lot of board level repairs, these days its kinda only the special cases or obvious that i even contemplate taking on.
 
Congrats on the fix, you beat the odds on that one.

Pretty much no one will issue circuit diagrams any more, oftern basic block diagrams, b.

thanks, I considered myself lucky too.

Too bad about the customer service thing, imo its a lousy outlook for a company to have. I've several old HP and Tektronix pieces of test equipment, you know, the stuff with complete schematics and repair instructions? They sure sent the message they cared about the customer with all that. At some point, given any one of these controller manufactures products can move stuff from A to B properly, perhaps one will realize great attitudes and customer service would be a good differentiator .Maybe its sort a Japanese company thing as well, very formal in a structured set of rules that aren't questioned. I needed a little part from Mitutoyo and was told there's a minimum order but they won't sell to me anyway, has to go through a dealer. I needed a Starrett part, walked into Starrett's office asked for a batter cover, and they gave me one, no charge! Whole different attitude. Then again maybe characterizing it as Japanese is perhaps unfair, there are lots of customer-hostile western world companies. Our only chance at changing it is hit them in the pocket book so when I encounter it, I try not to give them any more business
 
It might be a cultural thing, but I think it is based in business realities. I used to work pretty closely with Yaskawa when they were still building CNCs. In the 80s and very early 90s, they would sell boards and components for servo and spindle drives. Some time around 92 they stopped doing that would only sell rebuilt drives and had a "core charge" return credit. I asked them about that and the response was that they were having too much trouble with folks asking for credit on returned parts that were damaged in the customers attempts to repair a unit. It was kind of tough for some shops since the cost of the rebuilt drive was $1500 -$2500 versus replacing a $150 transistor module.
 
Somewhat to my surprise, I manage to fix this. The non working fan pointed at a fet and a daughter board that looked a little burnt. A leap of faith with an unknown Chinese board vendor (courier was as much as the board) and a new Fet and believe it or not it worked!

Was wondering if you had the photo of the damaged daughter board and FET. I have a drive MDS -B-SP-110 with the same symptoms. It is getting power but doesn't power up. The fan was caked up and blocked.
So you replaced both the daughter board and the FET?

Thank you
 
I know this is an old thread, but I have a dead drive with exactly the same symptoms. I was wondering if either of you had photos or if the repair lasted and if Sinij kot, did you get yours working?
 
hackish, I poked around at my drive but didn't find anything obviously wrong with it. There are several different boards in that drive. I checked few components like capacitors and diodes in the power section and looked for cold joints but nothing jumped out. I had to get the machine back up and running and was able to find a used drive on ebay. I think it was around $1200.
The old drive is sitting disassembled on the shelf. In case the replacement fails I'll have some parts to maybe Frankenstein something together.
 
hackish, I poked around at my drive but didn't find anything obviously wrong with it. There are several different boards in that drive. I checked few components like capacitors and diodes in the power section and looked for cold joints but nothing jumped out. I had to get the machine back up and running and was able to find a used drive on ebay. I think it was around $1200.
The old drive is sitting disassembled on the shelf. In case the replacement fails I'll have some parts to maybe Frankenstein something together.

I am in the process of ordering the board. I have done some sleuthing and I believe that 90% of the time it is just this board that fails. My drive has a full history of repairs. They show many components having been replaced. This is not my first time working on electronics. Looking at the board itself I can see that these were the only items changed. I'm anxious to get this thing running since I just purchased it, but I just hope the drive is good for the next few years... In your case, maybe you should do the same and test it so you have a unit in stock should you suffer another failure.

Do you mind taking some photos for future searches and for comparison sakes? I will do the same once I've confirmed the repair.
 








 
Back
Top