The Service Department

theservicedepartment
bystevegeorge

Wow, so many new recorders and formats to pick from! What brand, what recording medium, what number of channels? Decisions, decisions. It's worse than shopping for a PC! Gone are the simple days of having but two choices: analog tape or DAT.

So how does this affect my little repair world? Thankfully, not much at all (yet). In fact our number one recorder repair (quite a few each week) is still the Fostex PD-4, followed closely by the Nagra 4.2 and IV-S units, and then the HHB PortaDAT, et al.

We were amazingly busy repairing PD-2's last year, but those are finally tapering off as the machines are being replaced (often with pre-owned PD-4's!), because even after extensive repairs PD-2 long-term reliability is questionable.

With all the repairs on PD-4's, shouldn't people be replacing these obsolete recorders?

Remember, the Fostex PD-4 is just 12 months out of production, and in its final iteration, the PD-4M (with built-in MS headphone matrix) was a great recorder. New repair parts are available from Fostex, so a PD-4 is still cheaper to maintain than to buy a new recorder (complete with a new learning curve).

Well, there are several reasons for the increased number of PD-4s here for service. The number one reason is that many recordists are still sitting on the fence with regard to the non-linear units, waiting for just the right moment. The other reason is that the PD-4 is still very much a viable choice as a main recorder, and not just a backup -- although it will likely become that backup once their new nonlinear recorder is chosen.

Another reason for increased PD-4 activity is that Fostex no longer repairs DAT recorders in-house. At the same time Fostex enacted this policy, they trimmed the number of Authorized Service Centers to just a select few. Plus, since we at Trew Audio have earned a nice reputation among PD-4 owners as a good shop, word of mouth is generating a bunch of new clientele (thanks for all the referrals, folks! You know who you are).

Which brings us to the main reason for this article; how can we, as your Authorized Service Center, keep your PD-4 reliable?

I'll tell you. It's called Preventative Maintenance (AKA stopping future failures before they occur).

Courtesy of knowledge obtained at the School of Hard Knocks (years of extensive repairs of PD-4's), we learned not only how to fix them, but also got a decent insight into what makes them fail.

From this we've created a program of mostly physical retrofits and upgrades that help prevent future problems. The good news is that most of the maintenance procedure lasts for the life of the machine!

Here's what we do:

1. We remove and apply Loktite to 26 screws that commonly get loose. Three of them form the electrical GROUNDING for the Transport Controller Board and if they get loose cause all kinds of transport lunacy because they eventually fall out and short-circuit the Main Board (which costs $1000 to replace). Those three screws also get star washers applied for better security.

2. We epoxy the 15 LED Lenses. At least one will be sure to fall out and then you better pray they don't get into the Transport Gears. We epoxy ALL of them just to be safe.

3. While the Front Panel is apart to do the Lenses, we clean all 4 Gain Pots (Main, Channels 1-3 Gain Faders).

4. We glue (with a very special adhesive) the Top Panel plastic frame surrounding the Transport Plexi Lid. It will come loose (if not already) eventually causing downward pressure on the Capstan Bearing Cap, which either wears out the Capstan Motor or causes speed fluctuations with red LEDs galore -- or both.

5. We overhaul and LokTite the four Transport Shock Mounts. If and when the Right Rear Shock Mount works its way loose (they're spring-loaded) you will not be able to close the tape lid without damaging the lid mechanism. We lock all four.

6. We reroute the Transport Data Cabling for better RF immunity, and replace the ribbon cables if necessary.

7. We replace the plastic NP-1 Release Lever with a new one. (It's real fun bunging up your ATM card on location trying to get an NP-1 out when that lever breaks.)

8. We perform a visual inspection for dirt or oxidation. We remove all the dirt and sand, and if any evidence of corrosion is present, we coat it with either a light silicone or a heavier antioxidant depending on its location in the machine. We also clean and re-lube the Transport.

9. Once all the above steps are complete, we calibrate the unit to Fostex Spec's and send her home.

Average cost of the above Preventative Maintenance:
$200-$300 - a small price for such increased security.