Blown Resistor?

Yes, but not for that reason as the fault just suddenly manifested out of nowhere.

I bought mine for an absurdly low price at an auction of house contents (just over a hundred quid) - but spent almost ten times that amount on putting it back to original specification. You did very well with that relay in spotting that speck!

Well, it's all new to me having to deal with vintage tape. Back in the day, the tapes we had were still young and fresh and this issue simply never arose (not in my personal experience at any rate). My serviceman reckons it's a good idea to use IPA intially, then polish the heads with Autosol to get rid of any invisible remaining residue and it's an approach I now plan to stick to in future!

-known good test media (your reference)

-cleaned, demagnetized heads and transport (normal maintenance)

-rubber parts (degeneration)

-felt parts or anything dependent on adhesive (missing/moving)

-lubrication points (dirty or dry)

-any manually 'adjustible' parts (user damage)

-connectors (wear and tear) . . . . . electronics from power input to signal output.

Hasn't changed in 80yrs, regardless of format or end use.

RL

Mine came from a scrapyard in the days when the BBC disposed of their unwanted gear by that route. I invested in a copy of the full sevice manual, which meant I could do all the repairs and servicing myself. I was doing transfers from discs for the UK National Sound Archive and had to meet their specifications: every tape had to begin with a set of line-up tones to confirm that the azimuth and speed were spot-on and the bias settings and equalisation were correct for that particular reel of tape. If the playback wasn't within their specified limits, the tape came back and I had to do the whole job again (and didn't get paid until it was satisfactory).

Other transcriptors rather looked down on the Ferrographs as being dated, clunky battleships (one commented "You could play a length of bicycle chain on that thing!"), but I found they had been designed by people who actually had to use them professionally in arduous conditions, not by salesmen in plush showrooms. A tape path that looked so easy to thread in some other machines turned ito a contortionist's nightmare when it came to fast cut-and-splice editing because parts of the swish-looking casing got in the way of the tape when you needed to lift it out of the heads. The Ferrograph *was* clunky - and all the better for it.

Try not to leave the IPA on the pinch wheel for any length of time, as I have heard it can harden the rubber. If the pinch wheel tyre ever starts to go badly wrong (e.g. mushy), you can get away with cutting the rubber off and stacking 3 'O'-rings on the metal core until such time as you can get a proper replacement. Don't get the mush on your skin, it is dangerous.

I have never used Auto-Sol on the heads but I imagine it would be very effective - possibly a little too effective for anything other than occasional use in extreme circumstances.

I'm deeply humbled. I had no idea you were so experienced and venerable in this field. I can barely lift my L7 these days; not getting any younger. As you say, they're built like tanks. Not sure where they fit in the fidelity pantheon of high-end tape players. Some say better than Revox and the Swiss machines, others say not even close. But build-wise, they're virtually indestructible. Studio quality? Not quite, perhaps. But what do I know?

Ferrograph f***ed up badly at some point in their history as you no doubt know by using some weird compound on their pinch wheels which turned into a thick black gum which proceeded to jam the works up and make the most awful and hard to remove mess inside all the moving parts. I've had mine replaced with a compound which is compatible with IPA. The "dangerous mush" - would that be rich in hydrofluoric acid, perchance?

It's a very mild abrasive akin to toothpaste. My servicer has been doing F'graphs for almost 60 years now and recommends it, so I think you'll find it's safe enough!

My excuse is that I'm very old, so I have had plenty of time to gain experience. Working to a specification is a great way to learn and cultivate ulcers at the same time.

It was generally accepted that the Studer/Revox was very slightly better on paper - but that was offset by awkward servicing arrangements unless you were an agent with board-extenders, spare boards and a supply of the exact parts. I've seen a Ferrograph still working with the heads held on by wood screws.

They weren't the only ones who got caught by that batch of compound; some Philips models had the problem in their rubber drive-clutch pads but they generally didn't last long enough for it to become apparent.

It caused one of the worst nightmare scenarios of my career: I was using three Ferrrograph 7s (manual control, not Logic) to supply sound for a theatrical show. I was playing two machines alternately because the reels weren't big enough to hold the whole production, keeping the third as an emergency backup. At one of the final rehearsals they were left running all day as the producer constantly switched back and forth between musical numbers to give the cast the practice they needed.

Suddenly one of the machines ground to a halt, so I hastily switched to the standby machine. After a few minutes that one developed dreadful wow so I stopped it. The remaining machine kept going and I had some hasty tape-threading to do at the changeovers.

I took the two faulty machines away and dismantled them the next morning. In one of them, the compound from all three idler wheels had fused into a single gooey blob which had wrapped itself around the motor pulley, heated up from the churning effect, and then flown off in droplets over the entire works. In the other machine, the active wheel was gradually melting into the other two and dragging, also spreading sticky droplets throughout the works. Luckily my 'day job' was in a research establishment where one of the technicians warned me about the chemical risk.

Yes.

The technician produced a solvent (highly flammable!)which removed the mush that I hadn't been able to scrape off. Replacement wheels arrived by post the following morning and I fitted them in time for the first public performance that evening.

I'll give it a try next time I have a really persistent head-clog.