-- BobWicksall - 06 Jun 2019

Commodore 1902 Monitor

I have been unable to find a 1902 service manual but at least at first glance the Commodore 2002 monitor is a close match:

• Commodore_2002_Service_Manual.pdf
  • Capacitors on Page 25

• Layout and Electrolytics match on Power board and Video board
• Layout of Main board appears to be nearly identical
• Main Board markings on the 1902 are:
  • (5AS) 2061758-818 ELNA-87 94V-0
• Main Board markings on the 2002 Service Manual are:
  • (5AS) 2061758-800 ELNA-87 94V-0

Capacitor List

Note: These capacitor values and locations appear to match page 25 of the service manual for the Commodore 2002.

Main Board
C207	10uF (M)	25V	BP
C209	2.2uF (M)	50V
C210	220uF (M)	16V
C212	100uF (M)	16V
C213	1uF (M)	50V
C307	0.22uF (M)	25V
C308	0.22uF (M)	25V
C309	4.7uF (M)	50V
C310	0.22uF (M)	25V
C311	0.22uF (M)	25V
C401	47uF (M)	16V	4.7uF 25V and BP(NP) in 2002 service manual but actual value is on the left.
C402	4.7uF	25V	BP (Also not on the C2002 Capacitor list but is on the layout)
C403	2.2uF (M)	50V
C406	1uF (M)	50V
C413	100uF (M)	35V	Small
C414	1000uF (M)	25V
C415	22uF (M)	25V	BP
C416	220uF (M)	25V
C417	100uF (M)	16V
C420	10uF (M)	25V	BP
C441	4.7uF (M)	50V
C452	100uF (M)	35V	Small
C458	1uF (M)	50V
C460	10uF (M)	25V
C477	10uF (M)	25V
C478	1uF (M)	50V
C491	47uF (M)	16V
C511	22uF	160V
C512	33uF	160V
C701	47uF	160V
C703	1000uF	16V
C704	2200uF (M)	16V
C706	1000uF (M)	35V
C708	47uF (M)	35V
C710	1000uF	16V
C801	4.7uF (M)	50V
C802	4.7uF (M)	50V
C803	100uF (M)	16V
C805	330uF (M)	16V
C807	1000uF	16V
C809	10uF (M)	25V
C7218	22uF (M)	25V

Video P.C. Board
C201	1uF (M)	50V
C202	1uF (M)	50V
C203	100uF (M)	16V
C301	10uF (M)	25V

Neck P.C. Board
C251	10uF	160V

Power P.C. Board
C509	470uF	200V

These are on main board but under the shielding
C531	100uF (M)	10V
C535	100uF (M)	10V
C7201	330uF (M)	10V	Small
C7202	220uF (M)	16V	Small - Value in the manual is 330uF (M) 10V
C7203	330uF (M)	10V	Small
C7204	330uF (M)	10V	Small
C7207	1uF (M)	50V
C7208	10uF (M)	25V
C7209	10uF (M)	25V
C7210	10uF (M)	25V
C7211	33uF (M)	16V	Corrected. Typed 22 rather than 33 the first time.
C7212	1uF (M)	50V
C7213	1uF (M)	50V
C7214	220uF (M)	16V	Small
C7216	0.47uF (M)	50V
C7217	0.47uF (M)	50V
C7220	47uF (M)	10V	Value in the manual is 470uF (M) 10V

Other Parts

My board had a "Vertical Collapse" problem along with some leaky and bad capacitors. Replaciong the following part resolved my issue:

• uPC1378H - Vertical Deflection IC

Also purchased but didn't use:

• LA7823 Genuine SANYO Sync / Deflection IC

Pictures

• 1902_Top.jpg:
  

• 1902_Bottom.jpg:
  

• 1902_Cap_next_to_flyback_C512.jpg:
  

• 1902_Caps_around_flyback.jpg:
  

• 1902_Caps_under_harness_mess.jpg:
  

• 1902_Power_and_Video_Boards.jpg:
  

• 1902_Large_Heatsink_Label.jpg:
  

• 1902_Under_Shielding.jpg: