Bob042 Posted March 4, 2015 Share Posted March 4, 2015 Hi, Can anyone repair Clansman IBMU's? I've got one I'm not sure what to do with, either sell as is for spares/repair or get it repaired. Any help would be appreciated. Regards Bob Quote Link to comment Share on other sites More sharing options...
MatchFuzee Posted March 5, 2015 Share Posted March 5, 2015 You may find the manual for the IBMU here:- http://www.moffatig.com/emers/restricted_document_index.htm but you do have to be a member of the Vintage & Military Amateur Radio Society to be able to download it. Quote Link to comment Share on other sites More sharing options...
g0ozs Posted March 5, 2015 Share Posted March 5, 2015 Bob What seems to be wrong with the IBMU ? I havent ever seen spares for them apart from the battery trays and link cables so you are very likely to end up consuming another one for parts - as a microprocessor controlled piece of kit they are harder to debug and fix than the radios if the issue is non-trivial. Regards Iain Quote Link to comment Share on other sites More sharing options...
Bob042 Posted March 6, 2015 Author Share Posted March 6, 2015 (edited) Bob What seems to be wrong with the IBMU ? I havent ever seen spares for them apart from the battery trays and link cables so you are very likely to end up consuming another one for parts - as a microprocessor controlled piece of kit they are harder to debug and fix than the radios if the issue is non-trivial. Regards Iain Hi Iain It's dead, no power up. Supply checks out ok, fuse is present (but no way of checking as no spare). On power up they will go through self test if all ok but nothing happens with this one when switched on. The fuse is a 10amp v. small if I remember correctly but in my experience it's very unlikely to be that, BUT you never know unless you have known ok spare. Unfortunately I don't. Tomorrow I may be able to check fuse as by chance I have come across another IBMS, at cost I admit but not too bad. BTW you are right, they are v. difficult to repair if broke, parts are not easy so BER is often the end result unless you have a spare. Potentially I have a spare but who can do the job as I wouldn't know where to start. Will update. Thanks very much for your help. Regards Bob Edited March 6, 2015 by Bob042 added info Quote Link to comment Share on other sites More sharing options...
g0ozs Posted March 6, 2015 Share Posted March 6, 2015 Bob It's probably worth checking the fuse with an ohm meter or continuity tester out of circuit - if blown there is a quite considerable chance that a replacement will also blow due to a fault within the IBMU. I think PTS Norfolk (aka GTEN98 on e-Bay) are the most likely source of spare fuses in sufficient quantity to be able to risk some during repair. If it is completely dead and not doing the power on self test then I'd guess either the internal PSU is faulty, something is loose inside, or the microprocessor board is faulty. I think it would be worth a look inside before powering up with a new fuse in case anything is obviously loose and can be reconnected Regards Iain Quote Link to comment Share on other sites More sharing options...
Bob042 Posted March 7, 2015 Author Share Posted March 7, 2015 Bob It's probably worth checking the fuse with an ohm meter or continuity tester out of circuit - if blown there is a quite considerable chance that a replacement will also blow due to a fault within the IBMU. I think PTS Norfolk (aka GTEN98 on e-Bay) are the most likely source of spare fuses in sufficient quantity to be able to risk some during repair. If it is completely dead and not doing the power on self test then I'd guess either the internal PSU is faulty, something is loose inside, or the microprocessor board is faulty. I think it would be worth a look inside before powering up with a new fuse in case anything is obviously loose and can be reconnected Regards Iain Hi Iain Picked up the other IBMU today, powered up ok & went into test, no problems - I was ecstatic!. Alarmed up, ok so no problem, acknowledged the alarm which then displayed 'vLO' on the LED. After a couple of minutes alarmed again, so I acknowledged the alarm again and got the same 'vLO' on the display. I don't know what this alarm is. This continued and even after powering it down and back up again it continued to go straight into alarm. So initial euphoria replace by extreme annoyance. I swopped the fuses over between the two units and the dead IBMU fuse is ok, so must be major problem with that unit. So, this now leaves me with one dead IBMU and one that powers up but now goes into alarm mode and 'VLO' as soon as it is powered up. All I want is a gwo IBMU. Unfortunately I am not a member of VMARS (I should be) so cannot access their database. Is there anybody who can access the spares and has the knowledge to repair these things? Regards and thanks for yours and MatchFuzee's help Bob Quote Link to comment Share on other sites More sharing options...
g0ozs Posted March 7, 2015 Share Posted March 7, 2015 Bob If VLO is seen before a battery is placed on the tray it is likely the supply voltage is (or appears to the microprocessor) low - can you measure the supply voltage with a meter ? I dont know how low it can go and still work - when I had one I always ran it off a Clansman 50A mains PSU at 28V and never tried with batteries ? I have just moved house and my workshop is in boxes and distributed across the van, the garage, and three different storage facilities so I'm not really in a position to take on the repair If you are in Lincolnshire it would be worth a word with Colin G4DDI at Thorpe Camp if you ever go there both about the repair and joining VMARS Also note that the IBMU will refuse to charge very flat batteries - although my recollection is that it sees them as short circuit and reports s/c for the relevant tray position - you need a DCCU and slow charger tray to safely get them back to a sufficiently charged state that the IBMU will run a reconditioning cycle on them Regards Iain Quote Link to comment Share on other sites More sharing options...
Bob042 Posted March 8, 2015 Author Share Posted March 8, 2015 (edited) Bob If VLO is seen before a battery is placed on the tray it is likely the supply voltage is (or appears to the microprocessor) low - can you measure the supply voltage with a meter ? I dont know how low it can go and still work - when I had one I always ran it off a Clansman 50A mains PSU at 28V and never tried with batteries ? I have just moved house and my workshop is in boxes and distributed across the van, the garage, and three different storage facilities so I'm not really in a position to take on the repair If you are in Lincolnshire it would be worth a word with Colin G4DDI at Thorpe Camp if you ever go there both about the repair and joining VMARS Also note that the IBMU will refuse to charge very flat batteries - although my recollection is that it sees them as short circuit and reports s/c for the relevant tray position - you need a DCCU and slow charger tray to safely get them back to a sufficiently charged state that the IBMU will run a reconditioning cycle on them Regards Iain Hi Iain Thanks for the excellent info. The IBMU was connected direct to the vehicle supply in this instance, my Hawkers are in tip top condition and fully charged but I thought better to check it out direct from vehicle output. I measured the output at a steady 28.4v, which is what it always on my vehicle. This I believe is bang on what it should be. This being the case then for some reason the microprocessor is deciding its seeing a low voltage supply? This is slightly more encouraging news for me so maybe it's not too dire. There appears to be no output from the IBMU into the tray but that will be because of the alarm I assume? Where is Thorpe Camp? I am at Melton Mowbray, not far from the Lincolnshire border. Do you have a contact email address for Colin? Sorry to hear you cannot take on the repair at the moment, but I am in no rush at present. Importantly I did not know that IBMU's will not charge totally flat batteries. I have a DCCU and charging tray so I will bring a couple up. Regards Bob Edited March 8, 2015 by Bob042 Quote Link to comment Share on other sites More sharing options...
g0ozs Posted March 8, 2015 Share Posted March 8, 2015 (edited) Bob Colin is involved with Thorpe Camp museum near Woodhall Spa http://www.thorpecamp.org.uk/index.html, http://thorpecamp.wix.com/visitorscentre#!contact-us/cyha and http://www.dambusters-hamfest.net/ - he doesnt put an e-mail address on line so I probably shouldnt post it here - he should be contactable via Thorpe Camp as he is their webmaster - the radio shack page has a phone number at http://thorpecamp.wix.com/visitorscentre#!radio-shack/c210s Iain PS I agree it looks like the microprocessor is reporting low input incorrectly - maybe a PSU fault inside the IBMU or an a/d converter fault at a guess Edited March 8, 2015 by g0ozs add radio club details Quote Link to comment Share on other sites More sharing options...
Bob042 Posted March 8, 2015 Author Share Posted March 8, 2015 Hi Iain Now I know exactly where Thorpe is, not far away, many memories of the area back in the 60's travelling the highways and byways with my Father on his business. Who he didn't know as farmers in the area weren't worth knowing. Many a night spent at the Leagate Inn, watching the F4J Phantoms scream off the runway on QRF at RAF Coningsby, the afterburner on F4's was always spectacular as was their noise which they were known for, damned good aircraft though, I remember seeing the last of them in the early 80's. In later years I was at both Scampton and the nearer Waddington as well as being rolled to Coningsby which although not stationed there, I visited regularly. Regards Bob Quote Link to comment Share on other sites More sharing options...
Bob042 Posted March 13, 2015 Author Share Posted March 13, 2015 Looks like I'm going to have to have a go at this myself, anyone with any pics or info ( I have been fortunate to receive some which details the main problem areas and the Tants to replace) I would appreciate. There doesn't seem to be any EMER repair manuals available (non-listed on VMARS) but I am quite confident I can do the job. The spares are easy and cheap. I will use the "dead" IBMU as a guinea pig before attempting the "good" one. As said, any further gen will be gratefully received. Fortunately I work for an electrical engineering company, so help is available. One thing that has been suggested is to heat the legs of each suspect capacitor just in case its a dry solder issue. Anyone any thoughts on the merits of this? My intention is to document everything I do with pics etc, for the benefit of others facing this problem. Regards Bob Quote Link to comment Share on other sites More sharing options...
g0ozs Posted March 13, 2015 Share Posted March 13, 2015 Bob Reflowing potentially dry joints can do no harm and may find some problems - candidates are usually heavy components that rely on the PCB pins for mechanical support (so more likely transformers and connectors than tantalum capacitors) - the problem with the tantalums is that they can fail short circuit and do additional damage to other components subjected to high voltage or high current as a result. I will look forward to the pictures and updates Iain 73 de G0OZS Quote Link to comment Share on other sites More sharing options...
Bob042 Posted March 13, 2015 Author Share Posted March 13, 2015 Iain, Are you on about the white modules on the psu card folding back because of the tant short circuit? If so what's the prognosis? are spares available? I have yet to find out the issue, and need to understand what this means. Very interesting, Regards Bob Quote Link to comment Share on other sites More sharing options...
g0ozs Posted March 14, 2015 Share Posted March 14, 2015 Bob I havent been inside an IBMU - if it has commercial PSU modules then they probably will protect themselves from a short circuit as you say - I am more used to the tants failing in the PRC320 where usually the result is several transistors or an unobtainable undocumented voltage regulator IC being destroyed. Widney Aish who made the IBMS certainly used commercial Weir modules in the "10 amp" mains PSU for use with the IBMS so it doesnt surprise me if they did the same in the IBMS - I'd appreciate some internal photos as I sold mine several years ago without looking inside Regards Iain Quote Link to comment Share on other sites More sharing options...
Bob042 Posted March 14, 2015 Author Share Posted March 14, 2015 I have tried to post all the pics tonight over the last hour or so and it has crashed so will have to leave until tomorrow as fed up now as you can appreciate, this is not the first time I have had problems posting on this site. Bob Quote Link to comment Share on other sites More sharing options...
Bob042 Posted March 15, 2015 Author Share Posted March 15, 2015 (edited) Time to have another go. First of all you need a 3mm Allen key then undo all the retaining bolts on the front and rear plates, they are all captives so keep unscrewing until they run loose, you cannot lose them. Do not try to remove the back plate at this stage. The front control panel will now be loose. Using the carry handle, gently ease the front panel away from the casing; Behind the front panel is the controls pec with 2 connecting looms, a blue control loom to the right, then the output loom to the left. Next disconnect the blue control loom. Do this by lifting on the retaining catches to the top and bottom of the plug; Pull back on both catches at the same time and the plug will self extract, don't worry if there is a bit of resistance at first, just keep pulling back on the catches to their fullest extent and the plug comes free; Easy :-) I'm going to post this section now as I don't want a repeat of last nights disaster. Bob Edited March 15, 2015 by Bob042 Quote Link to comment Share on other sites More sharing options...
Bob042 Posted March 15, 2015 Author Share Posted March 15, 2015 (edited) In this section we will disconnect the output loom together with some observations on what I found. With the blue control loom disconnected, open up the front panel to the left of the unit casing; This will expose the inner retaining plate behind which sits the output loom connector plug and the main inner components of the IBMU; You will see the inner plate is held in place by 3 Allen bolts, ignore the two to the bottom left below the output loom. You also may be able to see here the evident whitish corrosion to the 3 Allen bolts; To the bottom right of the retaining plate you can see the evidence of moisture staining around the desiccant unit. Obviously the unit has not been serviced for some time and I don't know if replacement desiccant units are available. I am surprised at the evidence of moisture ingress to the unit, as I have taken apart much older Clansman stuff before and everything was as dry as a bone and shiny as the day it was assembled. A closer look at one of the screws below; Undo the 3 screws and withdraw the retainer plate; This will expose the output loom plug and its 2 retaining screws to the left and you get the first proper peek at all that lies inside the casing; Remove the 2 retaining screws from the plug; Gently ease the plug from its housing, the front control panel is now free; That's all for now, otherwise I shall be in trouble. more to follow soon. Don't be afraid to have a go! Regards Bob Edited March 15, 2015 by Bob042 Quote Link to comment Share on other sites More sharing options...
Bob042 Posted March 16, 2015 Author Share Posted March 16, 2015 Couple more pics from yesterday, Control panel pecs NSN Power input module NSN Regards Bob Quote Link to comment Share on other sites More sharing options...
g0ozs Posted March 17, 2015 Share Posted March 17, 2015 Bob Thanks for the photos. The corrosion is indeed a concern. I would be inclined to suspect it was opened previously and not closed in a hot dry environment or the seals weren't fitted properly. This may have been compounded by outdoor or semi-outdoor storage in a stillage while waiting to be sold. If the dessicator is the usual kind based on silica gel the dessicator can be restored by heating in an oven to expel the water from the silica gel crystals - I believe it needs to be 120 degrees C for a couple of hours. I note that there are a number of flexible PCBs used in place of a wiring loom - the IBMS is probably too new but I have had issues with those becoming brittle with age in other older products and being nearly impossible to reconnect reliably if solderless connectors are used to clamp the ends of the flexible ribbon in preference to soldered connections. The soldered connections are prime candidates for dry joints or tracks lifting off the flexible substrate if they are under stress all the time due to curvature of the ribbon. The blue connector with end levers is fairly typical of mid-1980s practice and are relatively reliable. Certainly I used them in things I designed in my day job at the time and had no trouble. Another cause of bad joints is where gold plated leads are soldered with ordinary solder. This results in a brittle alloy at the junction of gold and solder and fails relatively quickly - I had to resolder the offending boards after 6 months once dry joints started to appear the one time I made that mistake at work in 1988 or 89 ! Regards Iain Quote Link to comment Share on other sites More sharing options...
Bob042 Posted March 17, 2015 Author Share Posted March 17, 2015 Hi Iain, and anyone else watching this who may be able to help, More pics to come, but now I have the problem of identification. There are a number of cards which have cord attached to them, some is white cord, some black. I presume the cord is there in order to extract the card for replacement or repair? In saying this I assume the cards connect into the circuit board on the back plate?. I need to I.D. the PSU card, Analogue module and Logic module as they are the main areas of concern apparently. I have the tant numbers I need to replace. Bob Quote Link to comment Share on other sites More sharing options...
andym Posted March 17, 2015 Share Posted March 17, 2015 Just a thought, but have you considered what solder to use when conducting repairs? I suspect that the IBMU uses old-fashioned lead solder rather than the new-fangled ROHS stuff. Andy Quote Link to comment Share on other sites More sharing options...
andym Posted March 17, 2015 Share Posted March 17, 2015 Hi Iain, and anyone else watching this who may be able to help, More pics to come, but now I have the problem of identification. There are a number of cards which have cord attached to them, some is white cord, some black. I presume the cord is there in order to extract the card for replacement or repair? In saying this I assume the cards connect into the circuit board on the back plate?. I need to I.D. the PSU card, Analogue module and Logic module as they are the main areas of concern apparently. I have the tant numbers I need to replace. Bob A simple means of identification is to type the individual NSNs into Google. There are several sites that will give a description of NSNs. For example your power input module NSN above comes up as a filter assembly, which sounds right. Andy Quote Link to comment Share on other sites More sharing options...
Bob042 Posted March 17, 2015 Author Share Posted March 17, 2015 Hi Andy Thanks, good advice & much appreciated, never thought of that, Doh! The thing about this IBMU is that it is the one that does not power up which is why I'm using it as the guinea pig to get the knowledge prior to attempting repair to the one that does power but keeps going to low voltage fault. Now the question I'm asking is why does this one not power up? Has the damp ingress damaged it beyond repair? The cards look in good condition with no sign of corrosion. Take your point about the flexi pcb's Iain, have checked tonight and look ok. Gold plated leads, so what solder should be used, as Andy points out the original is highly probable lead? A couple more pics; Not sure what this pin is for, if you recall I said ignore the two retaining Allen screws earlier when removing the inner retaining plate. It actually locates into a graphite grey coloured block fixed to the bottom left of the card casing, you can just see it in this pic. Is it just for inner casing locating and retaining purposes? Again the pin and screws have suffered from moisture considerably; If somebody confirms I'm meant to pull the cards using the cords I will do, but I'm wary to do this as I don't want to damage a potentially repairable source of replacements?? Regards Bob Quote Link to comment Share on other sites More sharing options...
g0ozs Posted March 17, 2015 Share Posted March 17, 2015 Bob I havent been inside an IBMU - mine never gave any trouble when I had it - and don't have the EMER to hand - I agree with you that the cords are likely to be for card removal - if so they should come out without too much force. Hopefully someone here has done it before or has the EMER to hand but it should be ok to pull gently and see! The things with the corrosion generally look cadmium plated yellowish/copper - it's probably worth handling them with gloves to keep the H&S people happy in case and standing upwind when brushing off the white powdery corrosion outdoors. I think the pin looks more like a mechanical than an electrical function. Gold plated things shouldnt be affected by damp - if damp has done harm it will be to plain copper contacts that have tarnished, or steel components that have rusted. The IBMS is too recent to have paper capacitors or resin bonded paper boards that can hold damp in truly vintage radios - probably only transformers are likely to suffer from damp affecting the insulation breakdown voltage until dried out. The more worrying possibility is that if it was ever powered up damp the conductivity of moisture in transformers or on the surface of the PCBs may have affected circuit operation and done some collateral damage that will still be there when it is cleaned and dried out. I agree with Andy that the NSN method is usually ok for identifying cards - as to solder it would surely have been the original 60/40 Tin/Lead version when the IBMS was made. If forced to use ROHS solder it's best to desolder and clean the joint with a suction tool or solder wick braid and start over I think. Regards Iain Quote Link to comment Share on other sites More sharing options...
andym Posted March 17, 2015 Share Posted March 17, 2015 Personally I'd just use old-fashioned lead/tin multicore solder. I always thought the flux had a rather nice smell ... :-) Another annoying thing to consider - if you've got boards with microprocessors on them you should be thinking about anti-static precautions. A pukka wrist strap would be good, but touching something earthy before and during dismantling is a passable substitute. Hold the cards by their edges and try not to touch any of the computery bits. I agree that the spigot thing is some form of mechanical location but I can't for the life of me see from the photos what it's actually trying to do. Andy Quote Link to comment Share on other sites More sharing options...
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