N4000A Monitor Repair

I took the list of capacitors and checked every one of them (for capacitance and ESR). And, oh boy, 20 of them were defective! I replaced only the defective ones, eh voila, I now have a perfect picture on the screen again! Thank you so much for hinting towards problems with the capacitors!!

I also added a switch to the monitor to turn it off (cuts +12V and -12V) when not needed. This way I hope to extend the life of the picture tube (and avoid the infamous dimming).

FYI here is the list of capacitors from my N4000A with comments (sorry for the German words in there):

C nominal value voltage current capacitance ESR/Ohm comment new capacitance measured ESR/Ohm of new C

C2 22uF 100V 19.5uF 10.5 replaced 22uF 1.33

C3 330uF 35V 330uF 5.6 replaced 286uF 0.1

C5 100uF 100V 99uF 0.44 ok

C6 330uF 35V 286uF >40 replaced 335uF 0.58

C7 1000uF 35V 1139uF 0.78 ok

C8 1000uF 35V 943.7uF 0.67 ok

C11 22uF 100V 36uF 12.7 sollte ersetzt werden

C14 330uF 35V 332uF 0.47 ok, für C36 eingebaut, neu: 220uF, 25V 243uF 0.21

C15 330uF 35V 335uF 0.58 ok, für C6 eingebaut, neu: 220uF, 25V 254uF 0.29

C17 22uF 100V 18uF >40 replaced 19uF 8.6 (kein besserer da)

C24 330uF 6.3V 350uF 0.78 ok

C31 22uF 50V 16.5uF 0.9 replaced 25uF 0.56

C33 1200uF 35V ??? 0.24 ok

C34 1000uF 35V 904uF 0.91 ok

C35 22uF 50V 14uF 1.8 replaced 23uF 0.7

C36 330uF 35V 309uF 36 replaced with C14 332uF 0.47

C37 22uF 100V 21uF 14 should be replaced but no replacement available

C43 1uF 100V 0.73uF >40 replaced 1.6uF 1.6

C44 22uF 50V 11uF 7 replaced 23uF 0.5

C48 100uF 100V 104uF 6.4 should be replaced but no replacement available

C56 1uF 160V 0.0002 ?? replaced, new: 1uF, 350V 1uF 5.6

C62 22uF 100V 18.2uF 39.4 replaced, new: 300uF, 200V 290uF 0.08

C68 100uF 35V 64uF 1.3 replaced, new: 100uF, 64V 96uF 0.44

C69 22uF unipolar 25V 0uF ?? replaced by homemade cap 28uF 0.28

C70 22uF 50V 9uF 39 replaced 24uF 0.59

C80 1uF 50V 0.41uF 40 replaced 1uF 1.4 (auf Platinenunterseite gelötet, zwischen Pin8 (Masse) und 11 von IC4)

C99 47uF 50V 56uF 0.56 ok

C200 22uF 50V 12uF 6.4 replaced 26uF 0.38

C202 22uF 50V 12uF 5.2 replaced 24uF 0.38

Sound board:
alle SMD-C haben ca. 50uF und 2.3 Ohm ESR.
Grosser C hat 1798uF und 0.03 Ohm ESR.
Alles OK, nichts gewechselt.

C	nominal value	voltage	current capacitance	ESR/Ohm	comment	new capacitance measured	ESR/Ohm of new C
C2	22uF	100V	19.5uF	10.5	replaced	22uF	1.33
C3	330uF	35V	330uF	5.6	replaced	286uF	0.1
C5	100uF	100V	99uF	0.44	ok
C6	330uF	35V	286uF	>40	replaced	335uF	0.58
C7	1000uF	35V	1139uF	0.78	ok
C8	1000uF	35V	943.7uF	0.67	ok
C11	22uF	100V	36uF	12.7	sollte ersetzt werden
C14	330uF	35V	332uF	0.47	ok, für C36 eingebaut, neu: 220uF, 25V	243uF	0.21
C15	330uF	35V	335uF	0.58	ok, für C6 eingebaut, neu: 220uF, 25V	254uF	0.29
C17	22uF	100V	18uF	>40	replaced	19uF	8.6 (kein besserer da)
C24	330uF	6.3V	350uF	0.78	ok
C31	22uF	50V	16.5uF	0.9	replaced	25uF	0.56
C33	1200uF	35V	???	0.24	ok
C34	1000uF	35V	904uF	0.91	ok
C35	22uF	50V	14uF	1.8	replaced	23uF	0.7
C36	330uF	35V	309uF	36	replaced with C14	332uF	0.47
C37	22uF	100V	21uF	14	should be replaced but no replacement available
C43	1uF	100V	0.73uF	>40	replaced	1.6uF	1.6
C44	22uF	50V	11uF	7	replaced	23uF	0.5
C48	100uF	100V	104uF	6.4	should be replaced but no replacement available
C56	1uF	160V	0.0002	??	replaced, new: 1uF, 350V	1uF	5.6
C62	22uF	100V	18.2uF	39.4	replaced, new: 300uF, 200V	290uF	0.08
C68	100uF	35V	64uF	1.3	replaced, new: 100uF, 64V	96uF	0.44
C69	22uF unipolar	25V	0uF	??	replaced by homemade cap	28uF	0.28
C70	22uF	50V	9uF	39	replaced	24uF	0.59
C80	1uF	50V	0.41uF	40	replaced	1uF	1.4 (auf Platinenunterseite gelötet, zwischen Pin8 (Masse) und 11 von IC4)
C99	47uF	50V	56uF	0.56	ok
C200	22uF	50V	12uF	6.4	replaced	26uF	0.38
C202	22uF	50V	12uF	5.2	replaced	24uF	0.38