mitsubshi MSH-09NV-a1 service manual

[paul_h]

Has anyone got any mitsubishi service manuals?
I was called out to a split that had no remote control operation.
The split is good. (runs on manual button)
The remote is good. (turns on another wall split OK)
There's 5Vdc to the reciever pins, no output.

I just called ME au spare parts, and they are telling me the reciver is part of the main control PCB, so they want $120 for it. This is not the case though because the reciever is on it's own PCB and connected to the main PCB via flying lead.
SO I'm hoping someone has a sevice manual so I could check what this spare parts guy is saying and I won't be $120 out of my own pocket if he's wrong.

[andy c]

Hi paul, I've emailed you a manual. If you have another unit available, you could swap the parts over to prove the fault. Hope the manual helps. Have fun. Andy C.

[nike123]

Try to wash IC receiver with dump cloth. If that doesn't work, you should first change that electrolyte condenser near the receiver and if that doesn't work, change IC receiver which is universal piece of electronic available in any store with electronic parts.
Of course, first swap receivers between these two indoor units to make sure that is receiver and not main PCB faulty

[paul_h]

Try to wash IC receiver with dump cloth. If that doesn't work, you should first change that electrolyte condenser near the receiver and if that doesn't work, change IC receiver which is universal piece of electronic available in any store with electronic parts.
Of course, first swap receivers between these two indoor units to make sure that is receiver and not main PCB faulty
I've been meaning to ask you that for ages since I know you have heaps of electronics experience. Are the recievers pretty much universal, or does it depend on the a/c brand, do they use different frequencies etc?
I tried looking up recievers based on the part numbers stamped on one from a fuji ages ago, and there wasn't many resources/spares available by that model number in australia. I was never sure if any 5v dc one would do.
From your experience is it mainly that capacitor that goes first, ( haven't seen any leaking bulging one ever) , or the reciever, or the PCB itself?
edit: Pretty much the only places in australia that stock much electroninics is http://www.rsaustralia.com or http://au.farnell.com and I haven't had much like finding the type of recievers fuji or this mitsubishi use because I don;t have enough data on the frequency etc..

[nike123]

These receivers are simply transistor with base which is sensitive for IC light (photo transistor). When you press button on remote, series of IC flashes hit the base of transistor and he then amplify current according to that IC flashes.Than, that amplified signals are sent to indoor unit main PCB to control processor, and he then interpret them as it is programed.
There is no any frequency or anything else. It is only operating voltage of concern and that is 5V in 95% of all uses of these receivers. Other thing is sensitivity (range) and angle of receiving, but that satisfy almost all of such receivers for TV,DVD,etc.......
Yes, condensers fail more often then receivers.

This should be Ok:
http://tinyurl.com/2fgj5u

[paul_h]

Hot links don't work at that site, I just got a session timed out error, did you happen to get a part number?

Interesting, looking up farnell, the have receivers rated at 33khz, 36khz and 38khz.
http://au.farnell.com/jsp/search/browse.jsp?N=500001+1000033&Ntk=gensearch_001&Ntt=infrared+receiver&Ntx=
I know when the fluoro energy saving bulbs first came out, they would block the signal from the a/c remote, but never interfered with TV/DVD etc remotes. So I thought they were all different, otherwise your TV remote could turn your a/c on. (and I seen that happen on some cheap brands, but never name brands, so I thought most remotes operate on different frquencies.

[nike123]

That frequency is his maximum frequency and, if you are concerned about that, then go to max frequency when selecting model.

RS Stock No. 267-8324 http://img-asia.electrocomponents.com/au/img/site/symbols/newSmall.gif
For detailed informations try here:
http://www.rohm.com/products/shortform/28remote/remote_index.html

I will try to find data for Fujitsu receiver if that could be of some help to you.

[paul_h]

Cheers, I grab one of those sharp recievers you linked to at rs spares and give them a go.
One question, in the PDF for the reciever, it said no cap required, and as you say there's a chance the the existing cap could be faulty, do I leave the cap on the PCB there or bridge it out, or buy one and replace it just in case?


andy c, I'm not ignoring you, I just never got the email :o

[nike123]

Buy both, receiver and capacitor (10V electrolyte) and first change capacitor, then if that doesn't work fit only that receiver and remove capacitor and if that also doesn't work fit capacitor again. Watch for capacitor polarity. Use low power soldering tool or temperature regulated one. They are cheap these days. I use Weller temp. regulated. One of my best investment in tools.

When checking for correct operation, start first from short distance (few cm) then step back.