Apple AppleVision 850 Display Capacitor Replacement Guide

Main deflection board of an AppleVision 850AV with the electrolytic capacitors marked: CP (green), CL (blue) and CF (orange) (photo: Elemenoh, TinkerDifferent)

Electrolytic capacitors on the main deflection board of the AppleVision 850 and 850AV. Both models use the same main deflection board, Apple part 661-1213. Apple published no component list for it: its Service Source treats the board as a module and gives no schematic or component values.

The list below was compiled by a TinkerDifferent forum member, Elemenoh, from an 850AV board in 2022, with a photograph marking each position. It is a single owner's survey of one board, not an Apple parts list; check each position on your own board before ordering.

Safety

The main deflection board carries the power supply and the flyback circuit. The CRT anode runs at 27 kV. Unplug the display, discharge the CRT, remove the anode cap and fit an ongoing ground lead from the anode aperture to the CRT ground strap before removing the board, as Apple's take-apart procedure requires. See CRT Discharge Procedure. CP11 is a 100 µF, 400 V part and can hold a dangerous charge after the display is unplugged; discharge it before handling the board.

Main deflection board capacitor list

AppleVision 850AV main deflection board electrolytic capacitors (community list)

Position	Capacitance (µF)	Voltage (V)	Size, diameter × height (mm)	Temperature rating (°C)
CP9	68	25	6.5 × 11	105
CP10	1	50	5 × 11	105
CP11	100	400	22.3 × 30.3	105
CP12	47	250	16 × 31.5	105
CP13	270	100	13 × 42	105
CP14	470	16	8 × 20	105
CP15	1,000	16	10.25 × 30	105
CP16	1,000	16	10.25 × 30	105
CP17	1,500	16	13 × 25.5	105
CP25	470	10	8.2 × 15	105
CP28	100	25	6.5 × 15	105
CP29	22	35	5 × 12	105
CP40	22	50	6.5 × 12	105
CP41	1	50	5 × 12	105
CP42	2,200	35	16.2 × 37.2	105
CP44	820	25	10.3 × 31	105
CP51	1	50	5 × 12	105
CP67	22	35	5.3 × 11.5	105
CP68	47	16	5.3 × 11.5	85
CP69	47	16	5.3 × 11.5	85
CL2	22	250	13.2 × 26	105
CL6	470	10	8 × 15	105
CL21	47	100	10 × 21	105
CL27	22	250	13.2 × 26	105
CL37	100	25	6.5 × 10	85
CL38	470	16	8.3 × 20	105
CL43	100	16	6 × 12	85
CL58	100	16	6 × 12	85
CL61	1	50	5 × 10	85
CL62	10	50	5 × 11	85
CL84	100	16	6 × 12	85
CL87	2.2	200	6.5 × 12	85
CF1	220	35	10.5 × 13	85
CF2	220	16	8 × 12	85
CF4	1,000	16	10.3 × 20	85

The list has 35 capacitors: 20 in the CP series, 12 CL and 3 CF. The photograph also marks a CL72 that is not in the list, and does not mark CL27 or CL62; check those three positions on the board.

What the list does not cover

• The CRT/video (neck) board. The same owner later replaced "all 100 µF caps" on it without listing them.
• The 850AV's sound board (922-2650) and power board (922-2652) in the sound enclosure.
• The 850's ADB board.

Owner's findings

The owner measured the capacitors he suspected first (the secondary side of the power supply and the deflection circuits). Most were within a few per cent of their marked value; CP14 read 16% low, CP15 and CP16 12% low and CL6 11% low, and CL43, a bypass capacitor on the emitter of transistor QL20 in the horizontal circuit, read 22% low. He replaced CP14, CP15, CP16, CP25, CL6 and CL43. These replacements did not cure that display's fault, a narrow, distorted picture at all but one resolution, which is covered on the troubleshooting guide.

Procedure

1. Remove the housings and the main deflection board following Apple's take-apart chapter, with the CRT discharged and the ongoing ground lead fitted.
2. Photograph the board and note the polarity of every capacitor before removing any.
3. Replace one capacitor at a time with a part of the same capacitance and at least the same voltage rating, checking that taller replacements clear the heatsinks and the chassis.
4. Refit the board, reconnect the yoke wires to BF1 and BL1 clear of the ribbon cables (Apple gives bundling them as a cause of corrupted set-up data and a frozen screen), and check the high voltage reads 27 kV.

See Capacitor Failure Symptoms for signs of failed capacitors.

Related pages

• Apple AppleVision 850 Display
• Apple AppleVision 850AV Display
• Apple AppleVision 850 Display General Maintenance
• Apple AppleVision 850 Display Troubleshooting Guide
• CRT Discharge Procedure