I will be slowly transferring a log of service work I kept before starting the GReg/Electrical Tech Journal. It dates back to 2000. The info is pretty thin so I will try to flesh it out a bit. I'll omit redundant listings like mic re-ribboning, and fixing cables unless there is something unique about it.
I was learning a bunch as I went, so there might be some novice-minded solutions.
20/20 observations in different colors

Sometime in 2000
Equipment: Neumann M-7 Capsule
In:
Out: to Dirk Brauner
Repaired:
Date:

Equipment: Altec 21B Capsule
In:
Out: to Dirk Brauner
Repaired:
Date:

Equipment: Schoeps Capsule
In:
Out: to Dirk Brauner
Repaired:
Date:

Equipment: Neumann M58 Cap
In:
Out: to Dirk Brauner
Repaired:
Date:

Equipment: ATR 102 #3 (bought used, not working)
In: Take up tension sensor bounces causing the machine to unload anytime the transport is in forward motion.
Out:
Repaired: Blown trace on PWA motherboard, supplies +20V to reel servo board.
Date:2000
This was a very hard thing to find. The voltage appeared to be there when in stop mode, with the board on the extender, but drooped to nothing as soon as the machine went into action. I thought somewhere the current was being limited (which it was) and replaced the diodes and power transistors on the main deck plate, then swapped psu, then thought there must be something up with the motor, swapped that. Nothing had a positive effect. I pulled my hair out for a while. At some point I looked at the trace on the connector side of the card cage mother board, and saw a black dot on a trace. It looked like someone touched it with a fine tipped sharpie, no burn marks. It was feeding the +20v to the reel servo board. I think there was a rch of wire left, so I would see +20v when I measured around. As soon as the board needed more current, that dropped. After soldering in a jumper the machine operated normally.

Equipment: NTI EQ 3 (studio B) intermittent
In:
Out:
Repaired: replaced crappy in/out (bypass) switches
Date: 3/20/00 + 3/24/00 (for studio A's nti)

Equipment: Elite CH 4
In: No monitor solo
Out:
Repaired: trace broken - jumper put in
Date:

Equipment: Elite CH 4
In: Noisy Mic Pre
Out:
Repaired: blown electrolytic cap C111 upper board
Date: 3/22/00

Equipment: Ampex 351 #
In: Bad VU meter
Out:
Repaired: replaced
Date: 3/23/00

Equipment: Elite CH 46
In: Aux 7 pot bad
Out:
Repaired: replaced
Date: 4/3/00

Equipment: MCI ALII
In: not working well
Out:
Repaired:
Date:

Equipment: MCI ALIII
In: completely dead
Out:
Repaired:
Date:

Equipment: 2X Coles 4038
In:
Out: Coles
Repaired:
Date:

Equipment: Neve 6-pack
In: not working
Out:
Repaired: blown filter cap in the 24VDC power supply replaced
Date:

Equipment: Altec capsule
In: needs reworking, already cleaned
Out:
Repaired: capsule works OK - problem located on base
Date: 4/20/00

Equipment: Studer (black)
In:???
Out:
Repaired: replaced 2 remaining bridge rectifiers. all 4 new now.
Date:
Must have been something wrong with the power supply? I don't remember.

Equipment: MCI JH16
In: modification
Out:
Repaired: Modified the audio cards to be switchable between IEC+NAB 15IPS
Date:

Equipment: AKG 414 #2
In: sputtering noises
Out: AKG service
Repaired: back $7.00, cleaned switches
Date:

Equipment: AT4051
In: low output cap - spitting body
Out: AT
Repaired:
Date:

Equipment: Altec 175
In: dead
Out:
Repaired: replaced tube
Date: 5/29/00

Equipment: Crown GLM 100
In:
Out: crown for repair
Repaired: returned. works well. $68
Date:2000

Equipment: Josephson 609 + sidefire (KA32 capsule)
In: check sensitivity
Out:
Repaired:works fine compared to others
Date:

Equipment: MXR delay
In: noisy
Out:
Repaired: cleaned chip/pin connections
Date:

Equipment: C-24
In: 60Hz hum,
Out:
Repaired: high voltage regulator zener diode failed (1st norman made psu)
Date: 7/17/00

Equipment: U67
In: noise
Out:
Repaired: changed tube. ok
Date:

Equipment: Neumann SM-2 PSU
In: buzzing on mic
Out:
Repaired: rewired grounding scheme.
Date: 7/20

Equipment: Schoeps 21 Capsule M934C #5973
In: did not have any o/p
Out:
Repaired: cleaned connections, seems to work ok
Date: 7/28/00

Equipment: MXR Delay
In: bad memory chips on expansion board
Out:
Repaired: got replacements, works ok now
Date:

Equipment: Geffel UM70
In: capsule does not work
Out:
Repaired: two contacts in capsule housing not touching
Date: 12/00

Equipment: Schoeps 221 Body
In: not working
Out:
Repaired: Broken transformer primary. When ordering a replacement one from Schoeps, I found out the mic was a eastern european copy, and not a real 221. The only difference being the metal body, and output transformer. The capsule (real Schoeps capsule), tube and passive components were the same however. Knowing this, Schoeps was still nice enough to send us a new output transformer.
Date: 8/25/00

Equipment: ATR capstan servo pwa
In: 5V rail short
Out:
Repaired: preformed 5V 'heat' test, replaced A6 (short) + C29 (leaky)
Date: 8/24/00