landymad

got them from ebay, look nothing like the ones that come out but are the same spec. guess things get smaller lol

Evening all,

im happy to say my IBMU is up and running!!!

first thing i did was test the 15v on the test pins and was getting around 2v ish, after reading about C26, C14 22uF 16V (Output of +15V & -15V module) i suspected these may be at fault. now ive replaced them and everything seems to be working.

good luck with yours bob but i suspect it could be the same two capacitors that need changing

afternoon, the below may help.

i blew some of the psu capacitors trying to get the thing working, am waiting on a couple of capacitors to get my one going. think its C26 and C14 in the centre of the psu board that are at fault on my unit.

Fingers crossed.

IBMS preventative maintenance/repairs

 

The main faults with IBMUs are caused by short circuit Tantalum capacitors.

These cause the various power supply rails to go low volts and/or cause the two white modules on the PSU card to fold back.

 

All of the Tantalum capacitors in the IBMU should be treated as suspect!

The following are the most likely areas of failure and these should be changed first:

 

PSU CARD

 

C40, C34 33uF 25V (Part of 12V supply circuit)

 

C26, C14 22uF 16V (Output of +15V & -15V module)

 

ANALOGUE MODULE

 

C1, C5, C8, C9, C12 All 10uF 25V

 

LOGIC MODULE

 

C1 33uF 25V

 

The various voltages can be tested from the test pins on the front of the Analogue Module.

When working on the PSU card I normally power these individually from a current limited 24V laboratory power unit, this makes testing of the individual supply outputs much easier.

 

The PSU card also contains four 22uF 40V Tantalum capacitors, C11, C16, C20 & C38 these do not seem to give any problems, but should be suspected if there is no output on the 12V rail. (22uF 40V Tants are about £12 each so replacement of these could be expensive!) If needed I would use normal electrolytics 125 degree C type in these positions. This would keep the cost to sensible proportions where low ESR would not seem to be a prime requirement.

 

how did you get on Bob i have the same fault on my new ibmu :embarrassed:

Yeah I've had this email! Do they think we are daft?

Does anyone else know about this vehicle and the people that used them?

No its not my build would be good if it was, i am in the manufacturing stage of my build. Trying to work out what i need and how to make it at the moment.

anyone else with any pic's or info on these fantastic vehicles?

Hi and welcome.

Hi I'm currently fitting my 1972 lightweight out as a parra recce vehicle I have some bits sorted, like the rear gpmg mount and a front one (only the lower section mind) and also two replica gpmg's to go in them but am lacking good images and information on what these would have looked like in service. Does anyone have one that wouldn't mind taking some snaps for me? And does anyone have any information as to what they really looked like and what other bits do I need?

Thanks everyone.

Hi everyone, i have just got my first military vehicle a 1972 series III Land Rover Lightweight and thought i should get myself online and learn a little about it. My plan is to replicate a parra recce vehicle with it.