7
\$\begingroup\$

I'm trying to repair an old PC Engine game console and one of the missing components is a capacitor that looks just like a resistor. I'm not familiar with these and don't know how to read the colour bands or what a suitable modern equivalent might be. It's C137 in the picture, can anyone help? Thanks.

enter image description here

\$\endgroup\$
7
  • 3
    \$\begingroup\$ +1 for a decent photo. I can't help with the markings. \$\endgroup\$
    – Transistor
    Commented Jul 7, 2019 at 9:36
  • 2
    \$\begingroup\$ you sure it is a capacitor? there could be a mod record (somewhere) stating "C137 to be fitted with a 1k resistor, MELF". Where possible modifications will make use of available pads as it provides a more resilient connection and less mod time - NOTE: I am not saying that in this instance it is a 1k resistor, this was just a example \$\endgroup\$
    – user16222
    Commented Jul 7, 2019 at 9:40
  • 1
    \$\begingroup\$ Maybe it is just the same code like with resistors? 22 * 10^2 = 2.2nF? \$\endgroup\$
    – jusaca
    Commented Jul 7, 2019 at 9:43
  • 2
    \$\begingroup\$ C121 and 125 look like a capacitors, C137 looks so much like a MELF resistor, so much like the other Rs next to it, it's difficult to imagine it to be anything else. \$\endgroup\$
    – Neil_UK
    Commented Jul 7, 2019 at 9:44
  • \$\begingroup\$ I don't believe it's a resistor from multi-meter testing, all the R components in the same row give a resistance reading. Unfortunately, I don't have a way to measure capacitance. In case anyone was wondering, there are 2 of these on the motherboard so I'm able to test the one that's not missing. \$\endgroup\$
    – Prateek
    Commented Jul 7, 2019 at 9:50

2 Answers 2

Reset to default
1
\$\begingroup\$

Based on the color code (assuming all three bands are red and assuming it's a cap from the designator on the PCB), that's a 2.2nF MELF capacitor.

See also the photo in this question which shows some similar leaded parts.

The similarity of body color to the resistors is a bit disconcerting though, I suspect it might not actually be a capacitor, but there is no way to be sure without more information (or by measuring a good one).

\$\endgroup\$
2
  • \$\begingroup\$ It's really hard to tell if it's red red red or red red brown, but I agree it's more of a concern whether it's actually a capacitor. I think I might break down and buy a LCR meter as I'm getting nowhere with my basic multimeter. \$\endgroup\$
    – Prateek
    Commented Jul 7, 2019 at 11:20
  • 1
    \$\begingroup\$ @Prateek Desoldering it and trying to measure resistance should help. If it's still intact, and it's a capacitor, it will show open-circuit. If it's a resistor it'll show what its proper value is. Even using an LCR meter might not work with it still all connected in the circuit like that. \$\endgroup\$
    – Hearth
    Commented Jul 7, 2019 at 13:16
1
\$\begingroup\$

enter image description here

Brown-Red-Red Confirmed on IRfanview 1.2nF SMD eqiv 2010 or less enter image description here

\$\endgroup\$
4
  • \$\begingroup\$ I managed to get hold of a capacitance meter and the reading was 300pF. My assumption was that the bands are read from large to small which would indicate 220pF so it's not far off. \$\endgroup\$
    – Prateek
    Commented Jul 9, 2019 at 7:01
  • \$\begingroup\$ Or Orange Red Brown 320 pF \$\endgroup\$
    – D.A.S.
    Commented Jul 9, 2019 at 7:03
  • \$\begingroup\$ Yes, that's definitely a possibility. I might try my luck with a 300 or 330 ceramic as a replacement. \$\endgroup\$
    – Prateek
    Commented Jul 9, 2019 at 7:10
  • \$\begingroup\$ Probably an NPO cap \$\endgroup\$
    – D.A.S.
    Commented Jul 9, 2019 at 13:29

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.