11 March 2025 23:46-0400

NeXT Megapixel Display N4000 Repair

Dave Luna

Last weekend's repair project: A NeXT Megapixel Display with a wavy picture.

ESR testing the original capacitors to confirm my suspicions

I suspected a failing filter capacitor. I replaced that and the remaining 36-year-old electrolytic capacitors as a preventative measure. It was a time consuming process, but the surgery was a success.

This is how I felt after I finished the repair jobs:

My N4000's logic board (1-623-855-12) varied from the revision on AsteronTech's NeXT MegaPixel Refurb page. Here's the capacitor list for my specific version:

(Also available as a DigiKey list.)

ID	Capacitance	Voltage
2	22	100
3	330	35
5	100	100
6	330	35
7	1000	35
8	1000	35
11	22	100
14	330	35
15	330	35
17	22	100
24	22	50
31	22	50
33	1200	35
34	1000	35
35	22	50
36	330	35
37	22	100
43	1	100
44	22	50
44	22	50
48	22	50
56	1	100
62	22	100
38	100	35
69	22 (Bi-polar)	16
70	22	50
99	47	50
200	22	50