On arrival today the Argus wouldn’t boot. As soon as data started to be transferred from the CF card (disk) to the ME148 Store (memory) the parity LED on the ME148 lit and nothing else happened. A reseating of the ME148 and a clean of the edge connector made no difference. The ME148 that had now failed was the LCP spare used to replace the original ME148 which had also gone U/S. The original ME148 was still in the LCP. An observation; a lot of the faults we have with the A700 boards tend to be on units with mother and daughter combinations. – Store, GL and GX processors. It was, therefore, worth a go at the previously removed and U/S ME148, I (Pete H) cleaned the edge connector and then unscrewed the daughter board and easing it out before reseating it back on the mother board. I then put the original ME148 in the A700, switched on and all ‘S’ again. The simulator ran for a good period with no further problem. I now have the removed, original LCP spare, ME148 at home and I’ll give it the same treatment and see if it works OK in the test rig. The reson for the failures became evident when it was realised that the aperutures left by removal of air vents for cleaning and paint preparation had been covered with polythene to prevent ingress of vermin; unfortuantely this also stopped ingress of air causing condensation to form due to adverse humidity conditions … lessons learned!
Off-site work has included the thrilling task of cleaning external rubber connector covers. Some good quality tyre paint will hopefully restore the rubber and cover the green paint which has been randomly sprayed over the covers during in-service repainting.
The simulator is now ‘S’ again. An ME153 GL processor was used from the test rig to replace the U/S ME153.
Plenty of scraping and painting was had with Neil removing more of the residue of the top coat on the rear wall of the LCP cabin. I attacked the cable access panels on the right hand wall. Wire brushed and cleaned with sugar soap solution. All ready for painting.Neil and I put our heads together regarding the position of the LCP and could we leave the axles on the cabin? With apologies to our wood fettler Ian, Neil set about dismantling a large pallet to provide 3 metre lengths as shims to sit on top of the wooden sleepers. Giving an extra 1 cm of clearance allows us to leave the axles on the cabin and the wheels are clear of the floor. The plan is to move the LCP out from its current position to near the hangar doors, better light, better for paint drying etc. We then push it back when we pack up for the day.
Tried a software dump to tape in the LCP as Neil has now set MEZ’s and No Light zone configured. A box of old and used DC600A tapes were checked over this wee; almost all are unusable. The belts were stretched, snapped in use, had shiny sections where they rested on spindles and the tape itself, probably not used sine 1991, a key missing part. Amongst the tapes were sets labelled:- Swiss Dump 4A Issue 2- Bloodhound ADP- Bloodhound SZ Developer Tape (marked ‘Faulty’)For a few minutes I thought the developer tapes were for the UK software but under the faulty labels I could make out ‘SZ’. All the tapes on these cassettes have stretched, split or broken drive belts (see photo), some tapes had ‘sticky’ tape which stuck to itself. Symptoms due to storage for many years in poor conditions. I’ll short cut all the testing of tapes that I have done and get to a sort of resolution. In the box of tapes were some DC6250 tapes, not compatible with the A700 so I’ve used the belts from those on the DC600A tapes. The DC6250 belts are a bit smaller than DC600A or the DC6150 belts but as they are stretched they work with these tapes absolutely A OK and are a good firm fit. If necessary I can exchange the DC6250 belts with any cassette that has belt problems. The ¼” tape cassettes we use have one big weakness their belts and you can’t buy spares! I’m now thinking about our tape reliability as I did for the original A700 disk. Is there a solid state replacement? What I do know is that there is no SCSI to QIC-02 solid state emulator so it’s not an option to replace the tape drive. The tape drive though is not the problem, it’s the cassettes. What I am now thinking is; is it possible to copy all the utility/test programs to disk (CF card) on the A700? If this can be done then A700 formatted CF cards can be copied to create as many backups we need. The supplier of SCSICFDISK (Peripheral Vision) has PC software that copies CF cards no matter their format or what is on them. Perhaps Gustav can advise if copying a number of utilities to disk is possible. There is a tape with a disk image for test programs but is it the same?The ex-eBay G5 120A power supply (RIFA capacitors changed) has now been in use on the test rig for a good number of hours and remains ‘S’. We therefore have a spare in the LCP and of course a G5 120A on the test rig.
An initial batch of paint has been ordered: Etch primer, Matt NATO Green, MV primer (Ferrous materials), Black tyre paint and Fibreglass/plastic primer.