Computer Wizardry…

I don’t know much about computers, as this post will demonstrate…a while ago my friend Olivia gave me her nice HP Windows 10 laptop, because she was “sick of it”. She wanted a desktop computer instead, so I bought a Compaq 6000 all-in-one and gave it to her (seemed like a fair trade). She had it for a while, then told me it wouldn’t power up. Apparently she’d pulled the plug out of the wall accidentally when the computer was running, and now it wouldn’t start.  I went over to her house and sure enough the computer would display a “Windows didn’t shut down properly” screen, and if I selected a start option would go to a black screen and hang there. In the BIOS I made sure the computer was booting from the hard drive, restarted it and Windows appeared and seemed to be working fine. The other day she told me the same thing had happened – she’d been vacuuming and knocked the plug out of the wall. I went over on Sunday and this time the same trick didn’t work. I ran a diagnostic from the BIOS and it couldn’t detect the hard drive – “replace hard drive” was the recommendation. Oops. I texted a friend who knows a good computer repairer and got their phone number. I was just about to leave and thought, “I wonder if doing what caused the problem might fix the problem?” (I know, this isn’t even sensible). The computer was displaying a “Windows didn’t shut down properly” screen and I yanked the plug out of the wall. Plugged it back in, pressed the start button – the computer booted up and Windows appeared. Amazing. The legal definition of ‘dumb luck’, methinks…


Dual 505-2 Clicking…

My friend Michael’s son’s birthday tomorrow, and Michael has given me his old Dual 505-2 to fix up as a birthday present. I’ve gone through it pretty thoroughly and it seems to be working well: I’ve cleaned and lubricated the mechanism, fitted and set up a new cartridge, lubricated the spindle, fitted a new belt, polished the dustcover and plinth etc. etc. One thing I noticed today was a clicking sound coming from near the sub-platter. I know the trip lever (for the lever that stops you changing speed when the platter isn’t revolving) can stick and click against the sub-platter spur that actuates it, and apparently the motor can click if dry (although I’ve never noticed this) but this time it was the sub-platter spur hitting the belt once (and sometimes twice) per revolution. This turntable has no pitch belt, so I had adjusted the pitch with a strobe disc and spanner, winding the nut down on top of the expanding pulley until the strobe markings stood still. So I assumed that part was at the right height. I put a slightly heavier oil on the spindle to see if that would make the sub-platter a little higher, but it didn’t. I remembered the motor has washers on the motor mount shafts, and that the washers are different thicknesses. I moved the thick washers next to the motor, and put the thin washers above the rubber motor mounts, effectively lowering the motor assembly by about 0.5mm. This was enough to stop the top edge of the belt fouling on the underside of the sub-platter spur. I haven’t seen anyone suggest this as a remedy for Dual 505 clicking, so here it is…

Pioneer PL-960 Cueing Reservoir

The PL-960 is a fairly plasticky P-Mount fully automatic Quartz-lock Direct Drive turntable from the ’80s. I bought it ages ago and did some cleaning and lubrication, gave it a new stylus then set it aside. It had a dustcover but only one hinge. I had a go at adapting another hinge to replace the missing one, then gave up. Got it out recently and realised it was a fairly decent-sounding turntable. Has an Audio Technica AT3472P cartridge or something like that. I cleaned the speed pots, then set the speed with a strobe. The arm was dropping like a brick, so I dismantled the turntable to get to the cueing reservoir. I removed the base and the automatic mechanism, desoldered the tonearm wires, undid the nuts holding the arm in place and lifted it out, first removing the bottom bearings and then catching the top bearings as they fell out. I cleaned the arm lifter and applied some 300,000 CST silicone oil and reassembled everything. It took a couple of goes to get the pressure correct on the bearings – first time the arm wouldn’t move at all! The arm was dropping nice and slowly, but after a few days of listening I noticed a ‘chirp’ at the end of each record. I’d slowed the arm a bit too much – the stylus wasn’t lifting off the record completely before the auto mechanism swung the arm back to the rest. Today I tried a different approach – I undid the vertical bearing screws at the base of the tonearm and was able to lift the arm enough to get the arm lifter out. I cleaned some of the silicone oil off – originally I’d completely filled the notch in the lifter piston – and just left a thin layer overall. Reassembled it all, again I had a bit of trial and error with the vertical bearings – first time the arm wouldn’t land fully! But removing the lock nut on the right and adjusting the ‘cone’ (I guess it’s like a bicycle wheel cone) until the arm swung up and down freely seemed to do the trick. Ideally I should have a tool with a notch in the middle, so I can insert a screwdriver to hold the ‘cone’ steady while I’m tightening the lock nut, but the ‘cone’ didn’t move when I replaced the lock nut so all good! I guess Blind Freddie could have told me that putting lots of silicone oil in the arm lifter would slow it down a lot, but I guess ‘live and learn’…I’ve listed and sold this on Trademe and the woman who bought it is collecting it in a few days. Glad I’ve sorted out this last part of the puzzle. Oh, I had a random dustcover that I polished up, transferred the metal Pioneer label to, and strategically fitted some rubber equipment feet to lift the cover clear of the tonearm. The lack of hinges is probably a bit inconvenient, but it will do the job. Quite proud of this!




Fixed by Breaking

A while ago friend Olivia got me to replace the broken screen on her iPhone 5S.

A couple of weeks ago she told me the screen was lifting and the phone had developed ghost touch – it opened and closed apps at random, and pressing one part of the screen made something happen on another.

I replaced the screen, but told her the problem was probably caused by the phone having been bent at some point.

A couple of days later she told me I hadn’t fixed the problem.

I got the phone off her, straightened the housing using two pieces of wood and my bench vise, and cleaned the connectors on the logic board with isopropyl alcohol.

I gave the phone back to her and it worked perfectly – for a couple of hours.

Over the next few days she reported that the phone still had ghost touch.

I saw her tonight and asked her how the phone was going. She said it was working perfectly – she’d dropped it, the screen was cracked at the top right corner, and ghost touch had disappeared.

Turns out accident is a better phone repairer than me.


Fook Lever

This from the Yamaha P-751 service manual:

Fook Lever

I always wondered where the fook lever was.

Now I know.

Just bought a Yamaha P-751 for $20 on Trademe. The seller said it had just stopped working. I plugged it in, nothing. I noticed the fuse was blown, replaced it, the turntable spun for two seconds then stopped, fuse blown. Ahem…on the back the words ‘120 Volt’ stood out like dog’s balls (a particularly antipodean expression). Somebody had replaced the plug…I scavenged a power cable and moulded plug off a lamp, replaced the turntable cable and fuse, plugged the turntable into my stepdown transformer…and it went! Phew…the fuses must have saved the Yamaha’s transformer. Speed wouldn’t change…I looked at the PCB, and decided to test R15, the first component after the 33/45 pin. It was meant to be 100 Ohms, but was meg Ohms. Replaced it, speed changes now. I’ll do some work on it (probably replace the X capacitor across the AC line, it may have taken a hit) and it will go to a friend who wants a turntable. Fully automatic quartz-controlled direct drive. Nice-looking, nice-sounding and with ADJUSTABLE VTA, something you don’t see every day.

How to Land the Space Shuttle from Space – Bret Copeland

Just a truly great video – entertaining and informative. Thanks Bret! I guess there are valid objections to the shuttle program – it was born out of a political compromise, reusing the shuttle actually cost more per launch than the Saturn V/Apollo flights, it only flew into Low Earth Orbit, it was the deadliest space vehicle, etc. etc. But I still love the shuttle (or do I mean the orbiter?) – an amazing engineering achievement, and it did, after all, enable the building of the ISS and the launch of many satellites, including Hubble. And the people who flew it seem notably brave and capable. So, hats off…

iPhone 6 Plus LCD

Today, what a day! I replaced the screen on my friend Mike’s daughter’s iPhone 6 Plus. I’d never done one of these before and REALLY should have done a bit more research. However, with tools in hand and iFixit video cued up I embarked on this at 10:30am. It was not to prove simple…the main problem was battery removal: I heated the back of the phone moderately, pulled at the adhesive strips – and promptly broke them. I cut a thin piece of plastic and pushed it under the battery, slowly and surely levering it up and pulling away the adhesive. When I got the battery out I saw I’d broken the outer covering, and could smell the sweet-almond scent of electrolyte (cyanide? only wish it was!). I realised the battery was trashed. I continued, and tore the home button flex that runs up the back of the digitiser shield. I thought, I have to finish this today (customer is 16 and would die without her phone) so rang the first place I found and collected a new battery and shield + flex. It wasn’t Trademe, or ebay, cheap, but a retail outlet has a right to make a profit, nawmsayin’? However, Wellington Phone Repair at 37A Taranaki Street Wellington, New Zealand, was a perfectly obliging and amenable outfit. I chatted with their tech guy about the ins and outs of battery removal, then went next door to the skate shop retail area and bought my replacement parts. Thoroughly nice people, I haven’t had them repair anything but their down-to-earth friendliness and helpfulness leads me to believe they’d be worth checking out if you need something done to your phone. Back in my ‘workshop’, I did part of the repair then went to help my friend Alex set up the Lumia 930 I’d sold him. With mind reeling from downloading, installing and explaining I went back and completed the repair, which by some small miracle seems to be OK. The daughter has a friend who needs the same repair done to the same model iPhone, but I think I’ll have more of a clue about the 6 Plus the second time around. Here’s hoping…

Tonight I tried removing the battery from a broken iPhone 6 I’ve got in the drawer. I removed the vibrator motor (I think that’s what it is at the bottom end of the battery) and could see the broken-off ends of the adhesive strips under the battery. I used tweezers to grab one at a time, pulled gently and wwwrreeeeeaaaaaatttttttt (that’s a rough approximation of the sound they make) they came out, battery released! Note to self: always pull the adhesive SLOOOOOWLY!!

Adventures in old tech…until your mind reels…